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Latest research about heat pump innovation

scservicess@gmail.com (SHAH) — Sun, 21 Apr 2024 16:10:00 +0000

Heat pump technology has been undergoing continuous innovation to improve efficiency, reduce environmental impact, and expand applications. Here are some recent advancements and research areas in heat pump innovation:

Variable-Speed Compressors: Variable-speed or inverter-driven compressors adjust their speed based on demand, improving efficiency by matching output to the heating or cooling needs of a space.
Refrigerants: Research is focusing on developing environmentally friendly refrigerants with low global warming potential (GWP) and zero ozone depletion potential (ODP) to replace traditional refrigerants like R-410A.
Smart Heat Pumps: Integration with smart home technologies allows heat pumps to optimize performance based on occupancy, weather forecasts, and energy prices, leading to further energy savings.
Cold Climate Heat Pumps: Advances in cold climate heat pumps allow them to operate efficiently in colder temperatures, making them suitable for regions with harsh winters.
Hybrid Heat Pumps: Combining heat pumps with other heating technologies, such as gas or biomass boilers, in hybrid systems can further enhance efficiency and flexibility.
Thermally Driven Heat Pumps: Research is ongoing into thermally driven heat pumps that utilize waste heat or solar thermal energy to drive the heating or cooling process, improving overall efficiency.
Heat Pump Water Heaters: Innovations in heat pump water heaters aim to improve efficiency and reduce standby losses, making them more energy-efficient than conventional electric water heaters.
Modular Heat Pump Systems: Modular heat pump systems allow for scalability and flexibility, making them suitable for various applications from residential to commercial and industrial settings.
Heat Pump Integration with Renewable Energy Sources: Integrating heat pumps with renewable energy sources like solar photovoltaic (PV) panels or wind turbines can further reduce carbon emissions and energy costs.
Heat Pump Controls and Optimization: Advanced control algorithms and optimization techniques are being developed to maximize the performance and efficiency of heat pump systems under varying conditions.

Overall, ongoing research and innovation in heat pump technology are focused on improving efficiency, reducing environmental impact, and expanding the applicability of heat pumps in various sectors. These advancements aim to make heat pumps a more viable and sustainable heating and cooling solution for the future.

New Eco-friendly AC uses water to cool down Air

scservicess@gmail.com (SHAH) — Sun, 12 Jan 2020 17:32:00 +0000

A new type of air conditioning is waiting to make its cool debut on the market. Suitable for both indoor and outdoor use, the system is much more energy efficient than traditional units, uses plain water instead of chemicals refrigerants, and produces drinking water to boot.

With the winter holidays coming to a close, it’s time to plan for the future. The hot, sweaty, sticky near-future of summer. There is solid ground to assume that this year will be a scorching one, which should still feel like small fry compared to those in the future.

All this heat will not be doing anyone any favors. According to researchers from the Natural Resources Defense Council, future summers won’t be only about ice-cream and beach holidays — they will be very deadly seasons, claiming tens of thousands of lives all across the US. The EU is on the hook too, and there’s no reason to believe people in other areas of the world will fare much cooler than, essentially, the world’s technological and economic powerhouses.

Too hot for comfort

It’s not an overstatement, then, to say that proper temperature control, in the form of air conditioning, will become a matter of life or death in the future. However, our current approach to the issue leaves us in a spot of hot water.

For one, air conditioning isn’t so much about ‘destroying’ heat as it is about taking it somewhere else — specifically, out of the room. Comfy on the inside, but the reverse of the coin is that the ‘outside’, especially if you live in a big city, gets much warmer very fast. Le Chatelier’s principle on equilibrium tells us that this will make it progressively more difficult for air conditioning units to actually push all that heat outside: it’s more laborious to create a big imbalance (pumping heat from a cold room to a hot outside) than a small one (say, between two bodies at closer temperatures). It’s like pushing water uphill. Which segues us into issue Mk.2:

The harder our ACs have to work, the more energy they need. Ironically, this makes everything hotter, as that energy degrades into heat. It’ll also put a large dent in many a family’s finances, and many people will have to contend with an unenviable choice: go into overdraft, or gamble that nobody’s going to get heatstroke. Zooming back even further, it will put a huge strain on often aging and already-overtaxed power grids — and we definitely don’t want these to pop when everybody’s hugging the AC for dear life.

Lastly, our current systems employ chemical refrigerants such as chlorofluorocarbons and hydrochlorofluorocarbons for cooling, which are quite nasty for the environment. More directly important to you, however, is that these compounds are quite expensive to manufacture and very deadly if leaks occur indoors.

So we need a better alternative. Luckily for us, that’s exactly what one team of researchers from the National University of Singapore (NUS) has been working on, with support from the Building and Construction Authority and National Research Foundation Singapore. The device they came up with could potentially address the limitations of the century-old AC principle in use today.

The water-based AC system can cool air down to 18° Celsius (64.4° F) without using the energy-intensive compressors or the chemical refrigerants the most common ACs today use. Suitable both for indoor and outdoor use, the device is fully portable and can be customized to work in all weather conditions, says the team led by Associate Professor Ernest Chua from the university’s Faculty of Engineering.

Cooler cooling
Because it relies on water in lieu of chemical refrigerants, the device is also cheaper to manufacture than traditional AC systems, is more sustainable, more eco-friendly, and potential leaks will be a nuisance at their worst. Running costs should also be much lower, as the team reports their cooler uses roughly 40% less electricity than traditional systems — good for your bill and the planet, too.

A final feature you’ll enjoy on a scorching noon is that the system also generates potable water as it cools your room.

“For buildings located in the tropics, more than 40 per cent of the building’s energy consumption is attributed to air-conditioning,” Chua says. “We expect this rate to increase dramatically, adding an extra punch to global warming.”

“Our novel membrane and water-based cooling technology is very eco-friendly — it can provide cool and dry air without using a compressor and chemical refrigerants. This is a new starting point for the next generation of air-conditioners, and our technology has immense potential to disrupt how air-conditioning has traditionally been provided.”

Instead of dehumidifying and cooling the air at the same time, as conventional designs do, the team from NUS decided to handle them separately. Finer control over each process allowed the team to increase their energy efficiency.

The first step in the process is to pass air through a paper-like membrane which removes moisture. Then, the dry air is passed through a dew-point cooking system. In broad lines, this is a system that uses part of the dry air produced in the first step to force evaporation on metallic plates inside the AC. Since water needs energy to turn into a gas (and heat is energy), this process cools the plates which, in turn, cool the air flowing through them. Out the end comes a stream of cooled, drier air than compared to the environment, and about 12 to 15 liters (12.68 to 15.85 quarts) of potable water per day.

According to the team, the device can easily be adapted to work in all types of weather and climate, used for individual homes or scaled up to service clusters of buildings. The team says it’s particularly well-suited for confined areas that need reliable humidity control, such as bomb shelters, wine cellars, or hospitals. “Armoured personnel carriers, and operation decks of navy ships as well as aircrafts,” are also good candidates, Chua adds.

The team is currently refining its design to further improve user-friendliness. They plan to incorporate features including pre-programmed thermal settings, based on human occupancy, and real-time tracking of its energy efficiency. The team hopes to work with industry partners to commercialize the technology.

VISIT: https://www.zmescience.com/science/water-based-air-conditioning/

Commercial Refrigerator Troubleshooting

scservicess@gmail.com (SHAH) — Mon, 21 Oct 2019 13:01:00 +0000

Is this a commercial refrigerator troubleshooting call for a unit that's totally "dead"?

If it's plugged into a wall outlet, you'll need to check the outlet for power, and it's always a good idea to verify that the ground and neutral are wired correctly.

If it's wired to a disconnect, you'll need to check for power in the disconnect, and once again, it's always a good idea to verify that the ground and neutral are wired correctly.

If there's no power in the outlet or disconnect, you're going to have to find out why, and correct it.

If there is power in the outlet or disconnect, check the plug, or the connections in the disconnect; then check the wiring and connections into the unit to see if there's a broken wire or loose connection.

A non-contact voltage detector is a quick way to find broken wires and open connections, on commercial refrigerator troubleshooting calls, or on any HVACR service call.

If there is an on/off switch on the unit, check it to see if it's working.

Be sure you have a good neutral.

You might read a good voltage from your hot line to ground, but if your neutral line is bad, your unit won't run.

Is this a commercial refrigerator troubleshooting call for a unit that's freezing up?

Make sure the evaporator fan is running, and that it's rotating correctly.

You may have to melt the ice off the evaporator first.

Make sure the coil is clean, and that the drain line is clear.

If only the first section of evaporator piping is freezing up, you very likely have a low charge, or possibly a restricted drier, liquid line, or metering device.

Check your pressures, temperatures, superheat, and subcooling.

Our System Evaluation Manual has a cycle diagram and guidelines for evaluating pressures and temperatures for air conditioning and refrigeration systems.

Is this a commercial refrigerator troubleshooting call for a unit that might have a compressor problem?

Before you attatch your gauges, is the compressor doing anything at all?

Is it pulling any amperage?

Is the compressor hot?

If it's making a sound like "mmmmmm-TINK.....mmmmmmmm-TINK", it's trying to start, but tripping off on its overload.

Disconnect the wiring from the compressor terminals and check the resistances of the windings.

If there's an open winding, you'll have to replace the compressor.

If the compressor is very hot, the internal overload may be open.

It will take time for this to cool down and close, so don't condem the compressor yet.

You can either wait until it's cool, or cool it down with ice.

Once the overload closes, if the windings test OK, replace the start components and try to run the unit.

If the compressor runs, the unit should cool ok if there are no other problems.

If the compressor makes the "mmmm-TINK" noise again, it's locked up, and must be replaced.

If the compressor is running, with very low amp draw, very high suction pressure and very low discharge pressure, it has failed, and must be replaced.

Try to determine why it failed.

Is the condenser fan running?

Is the condenser coil clean?

Is hot air blowing into the condenser coil from another appliance?

If you're on a commercial refrigerator troubleshooting call and the compressor is running with low amp draw, low suction pressure and low discharge pressure, you may have a low charge, or a restricted liquid line, drier, or metering device.

Check the superheat and subcooling, and make the necessary repairs.

Is this a commercial refrigerator troubleshooting call for a unit that's cooling but not maintaining the correct refrigerator temperature?

Verify that the operating pressures, temperatures, superheat, and subcooling are in the normal range.

Make sure the gaskets are in good condition, are correct for the door, and are sealing good.

If the temperature control is turned to its coldest setting, and it turns off the compressor at too warm a temperature, it has failed.

Replace it.

On every commercial refrigerator troubleshooting call, check the fans; make sure they're running, turning in the right direction, and that the blades and motors are the right size.

Check the coils, and make sure they're clean.

Make sure no controls or safeties are by-passed.

Make sure the panels, grills, and enclosures around the fans and coils are installed and providing good air flow.

Verify that the supply voltage, operating pressures, temperatures, superheat, and subcooling are in the normal range.

VISIT: CLICK HERE

How Does A Water Cooler Work?

scservicess@gmail.com (SHAH) — Sun, 04 Aug 2019 05:33:00 +0000

How Does A Water Cooler Work?

In our universe, heat can travel in only one direction: from a higher temperature to a lower temperature. Therefore, it seems that water coolers, along with refrigerators and air-conditioners, by freezing fluids (air and water), defy one of the most fundamental laws of nature!

Of course, this is untrue. In fact, it’s impossible, yet these machines are ubiquitous today – indispensable, in fact, to some. What magic is then obscured behind those curved walls of metal and plastic that enables the machine to achieve such a transformation?

Water cooler working principle

The working principle of a cooler, or for that matter, a refrigerator or air-conditioner, is quite simple: introduce the object whose temperature you wish to decrease to an even colder object, so that when the heat from the hot object is transferred to the colder object, the former is rendered cold. Similarly, water is made colder by acquainting it with an even colder fluid. It surrenders its heat to this colder fluid, thus becoming colder itself. Heat is still traveling in the only direction it can, meaning that no fundamental laws of physics are violated.
However, bear in mind that we desire cold water at room temperature or an even lower temperature, which means that this magic liquid must boil — thereby extracting water’s heat — at room temperature. What’s more, it must also freeze at a meager temperature, since it must be refrozen to be reheated. Otherwise, one would be required to refill the machine with more magic fluid each time all of it is heated, thus rendering it unusable for further use.

The magic fluid that boils and freezes at a very low temperature is called a refrigerant. Consider, for instance, one of the most commonly employed refrigerants, which is called R22. While water boils at 100 degrees Celsius, R22 boils at an astounding -40.8 degrees Celsius! However, refrigerants are not amazing because they boil from a liquid into a vapor or condense from a vapor into a liquid at a low temperature, but rather because they do so very rapidly and seamlessly. How and why is irrelevant to our present discussion. Now, let’s wrap our heads around how the components of a water cooler exploit this property to cool water.

The water is introduced to the cooler by filling a container called the cooler reservoir. The reservoir is effectively a mini-fridge and is therefore often called the bank fridge. The reservoir is surrounded by coils in which the refrigerant flows.

The cooler has four major components: the compressor, the condenser, the expansion valve and the evaporator.

First, the low-pressure and low-temperature refrigerant gas is pumped into the compressor. The compressor, as the name suggests, compresses the gas, thereby raising its pressure. What the compressor does, by pushing the piston over the gas, is reduce the volume that the same number of molecules previously occupied. This causes them to collide more frantically with each other. These collisions elevate the pressure and temperature of the gas. This is exactly why a bike pump becomes hotter when we pump it vigorously.

The high-pressure, high-temperature gas is then passed onto the condenser. As the name suggests, it condenses the gas, meaning that it decreases its temperature. This is achieved by making it flow in long, circuitous coils. The area of the tubes is optimized to achieve maximum condensation. An additional loss of heat is achieved by blowing on the pipes with a fan. The condenser causes the gas to lose its heat in the same way that blowing on your hot coffee makes it more tolerable. The extracted heat is vented out into the surroundings, which is why the back of your fridge is always so warm.

The gas is now converted into a liquid of moderate pressure and temperature. The temperature of this refrigerant is further decreased by squeezing it through an expansion valve. An expansion valve is very similar to the nozzle of a spray can. The liquid inside the can is pressurized, but when one pushes the nozzle, the liquid spurts out into a region of low pressure. When the compressed liquid enters such a region, it immediately expands. This expansion, representing a decline in pressure, simultaneously causes a drop in temperature. You have probably experienced how cold the liquid is that leaks from the nozzle incidentally. Therefore, our refrigerant, after exiting the valve, becomes a cold, low/moderate-pressure liquid.

Now, the final component, the component that produces our cold, thirst-quenching water. This last component is called the evaporator. The evaporator in an air-conditioner is a system that comprises a fan to suck in the air of the region intended to be cooled. The temperature of this air is significantly higher than the boiling point of the refrigerant. The cold refrigerant enters the evaporator in pipes, which are exposed to the “warm” air the evaporator sucked in. Heat flows in only one direction. The heat of the air is transferred to the refrigerant, thus making it hotter. The air, now divested of heat, is recirculated into the region through a vent. Voila! Cold air!

The image below neatly summarizes the entire process of cooling.

However, a water cooler doesn’t necessarily employ a separate, dedicated mechanical unit to evaporate the cold refrigerant. The coils that surround the reservoir often form the condenser itself. The “warm” water surrounded by cold coils transfers its heat to them, and what pours out of the faucet is cold and rejuvenating water. The refrigerant in the pipes, now heated, is pumped into the compressor and the cycle repeats.

Akash Peshin 9 Months Ago
The short URL of the present article is: http://sciabc.us/unir9

Scientists discover potential sustainable energy technology for the household refrigerator

scservicess@gmail.com (SHAH) — Sun, 21 Apr 2019 08:35:00 +0000

Date:

March 28, 2019

Source:

American Institute of Physics

Summary:

While many advancements have been in improving its efficiency, the refrigerator still consumes
considerable energy each year. So researchers in China are working to minimize the cold loss that occurs
at the thermal barrier between inside the freezer and outside the fridge. They hypothesized that using
part of the cold loss to cool the fresh food compartment could be a promising solution.

While many advancements have been in improving its efficiency, the refrigerator still consumes
considerable amounts of energy each year.

"Energy efficiency of a normal refrigerator is affected by the heat-insulating property of the thermal barriers
of the freezer. This is due to its low inner temperature," explained Jingyu Cao at the University of Science
and Technology of China. "There is a significant difference in temperature between the freezer of a
traditional refrigerator and ambient air temperature and the normal thermal barrier of the freezer causes
considerable cold loss."

Cao and his team hypothesized that using part of the cold loss to cool the fresh food compartment could be
a promising solution in improving the efficiency of the refrigerator. They describe their findings in the
Journal of Renewable and Sustainable Energy, from AIP Publishing.

"The evaporating temperature of the refrigeration cycle depends only on the freezer temperature and
appropriate reduction of the evaporator area in the fresh food compartment will not decrease the overall
efficiency," explained Cao.

"Most families need one or two refrigerators and they are always on 24 hours a day, 365 days a year.
That wastes a lot of energy. Even if we can save a little energy, that helps the human race be more
energy-efficient," said Cao.

Cao and his team are not the first scientists to attempt to improve the efficiency of household refrigeration.
Extensive experiments by many different scientists have looked at various parts of the refrigerator to
improve energy consumption, but a definitive solution has not yet been found. In Cao's study, a novel
refrigerator with a loop thermosyphon is put forward to decrease the heat transfer between the freezer and
ambient air.

"One of the surprises was how much energy we saved. The energy-saving ratio of the improved walls got
close to 30 percent -- more than we had expected. This technology even works in hot climates like the
desert."

Although Cao's study is currently based on theoretical calculation, the results are promising. "It has great
potential to be popularized as a sustainable energy technology or applied in the renewable energy field,
considering its significant energy-saving effect, simple structure and low cost," said Cao.

Story Source:

Materials provided by American Institute of Physics. Note: Content may be edited for style and length.

visit:https://www.sciencedaily.com/releases/2019/03/190328150937.htm

Experimental Study of the Performance of a New Developed Heat Pump Water Heater with Frozen Evaporator

scservicess@gmail.com (SHAH) — Tue, 12 Feb 2019 13:15:00 +0000

Abstract

Heat pumps are a part of the environmentally friendly technologies using renewable energy and have been utilized in HVAC systems. A heat pump water heater unit with frozen type evaporator was designed and developed. And a test bed was constructed to determine the performance of the unit. In the experiment, a parallel helical coil type evaporator was used in the unit to extract latent heat from the sewage. The data (dynamic COP and other parameters) was obtained in three processes(including the first freezing, melting, and the second freezing) at different water temperatures (8.2℃ and 13.8℃). Results show that compare with traditional water source heat pumps, the newly designed unit with the frozen evaporator can reduce the required water amounts as a heat source by more than 90%. The higher initial temperature of hot water and sewage, the higher temperature of sewage after melting. Meanwhile, with the increase of the initial temperature of hot water and sewage, the comprehensive COP was greater. This paper will provide a reference for the sewage source heat pump system to extract the latent heat from the sewage.

For more deatails please visit Click Here

Whirlpool Stainless – Best Water Dispenser Bottom Load

scservicess@gmail.com (SHAH) — Sat, 08 Sep 2018 18:49:00 +0000

You wish you had a self-cleaning water dispenser?
Yes, this is it.
The others have been dishwasher safe, but this one is self-cleaning. This is due to its 6th sense technology, and then it uses unstable oxygen in order to kill bacteria and other viruses that can be contaminating your water.
It is nice and sleek for your office since it is made of stainless steel. And it even has a nickel planted front and sides for a sleek and sophisticated, edgy design. Look wise, this to me is the most aesthetically pleasing to the eye.
It screams sophistication and luxury, but the price tag does not. It is a personal favourite of mine.
Pros:
This is the companies 5th generation of bottom loading water dispensers so they know what they are doing
The LED light lets you know when the self-cleaning is running.
The LED will also allow you to know when the water is at its coldest or at its hottest
The coldest the water gets is 9° F which is well below freezing The hot water is hot enough to brew the perfect cup of tea, which is hotter than water for a cup of coffee
A 300 pound person can sit on the water dispenser and not break it Will outlast other brands since the compressor is not used as often due to the cooling system Is able to use 3 or 5 gallon water jugs which seem to be the two most popular sizes
Cons
Only offers are freezing cold or boiling hot water. In order to achieve room temperature you need to leave the poured water out Since it is stainless steel, it shoes stains and finger prints all over the appliance. Keep a rag handy

Design and Development of Modified Air Cooler cum Storage System

scservicess@gmail.com (SHAH) — Wed, 23 May 2018 20:18:00 +0000

Abstract-

The modified air cooler cum storage system

is a type of conventional air cooler which is used for providing

room cooling as well refrigeration systems. The system

consists of a lower tank which is a mud pot whose outer

periphery is filled by sand slurry. The lower tank and the

slurry are held by a larger mud pot, i.e., a pot-in-pot system.

The lower tank is filled with water and it is connected to the

upper tray through a pump. The water in the upper tray is

passed through a cooling pad which is used for absorbing the

water. A fan is fixed next to the cooling pad and is followed by

a vent system. The tray also has another port which is

connected to the cold storage box. On running the system for 5

hours, the temperature of a 960 cubic feet room gets reduced

by 12o C and the temperature of the cold storage box gets

reduced by 11o C and reaches 24o C, hence providing the right

temperature for storage of perishable items.

Keywords - Evaporative Cooling, Heat Transfer, Sir

Cooler, Pot System.

I. INTRODUCTION

India is a tropical country in which most of the regions

experience very low temperatures during the winter and

very high temperatures during the summer seasons. That

is, the temperature range between summer and winter

seasons is very large. Hence, it is not a very pleasant

experience and highly uncomfortable. Though cheaper

methods of heating are available during the winter

season, methods of cooling down the hot temperatures during

the summer do not have wide variety of options. Air

conditioners have high initial and running costs, which cannot

be afforded by all the people in a developing country like

India. Air coolers are relatively cheap, but provide

unsatisfactory results; there is a need for developing a cheaper

room cooling system. Conventional air conditioning is one of

the major contributors of CFCs into the atmosphere. An

alternative type of cooling, which does not expel CFCs is

highly desirable as one important step in the correction of this

problem. So, this is why adiabatic cooling is environmentally friendly because it is a passive cooling method that does not

expel CFCs. It is 100% fresh air-cooling which even helps to

clean the air it cools. With the help of Evaporative Technology

swamp coolers provide cooling at cheaper than central air or

larger air conditioners.

A Regenerative type evaporative cooler cools air using a heat exchanger in addition to the direct evaporative method of cooling. It is observed that the overall efficiency of

the system and the COP increase by about 20-25% than the

normal air cooler system but the initial and maintenance costs

of the system are increased due to the addition of a heat

exchanger and a pump. The size of the system also increases

due to the addition of more components.

A multi- utility desert cooler is one in which

water cooling as well as cold storage systems are attached in

addition to the air cooling system. The average effectiveness

was found to be 65.42% and a temperature range of 22-27o C

was achieved. It can be used only in areas with high

temperature and low relative humidity hence reducing its

scope.

Ndukwu Macmanus Chinenye developed a clay

evaporative cooler for the purpose of preservation of fruits and

vegetables at a lower temperature and also to study the

physical parameters such as cooling efficiency, cooling

capacity, etc. in the system. The results showed that the

evaporative cooler reduces the temperature up to 10o C and

increases the relative humidity of incoming air for the storage

chamber. The evaporative cooler was able to preserve freshly

harvested tomatoes for about 19 days. It is observed that clay

is a material which helps in evaporative cooling and has

shown proven results and hence can be used as a vital element

in the air cooling system.

Hence, it is proposed to build an air cooler which

provides better room cooling in addition to providing a cold

storage box for refrigeration purpose at a cheap initial, running

and maintenance costs which will meet the demands of a large

section of the society who find it difficult to bear the hot

temperatures.

Types of Chillers

scservicess@gmail.com (SHAH) — Sat, 11 Nov 2017 14:41:00 +0000

Click Here

Ground-source heat pump renaissance

scservicess@gmail.com (SHAH) — Thu, 26 Oct 2017 03:17:00 +0000

Dandelion uses this photo in all of its promotional materials, although the image doesn't show what the system actually looks like in any capacity. But perhaps it reflects the target structure that would benefit from a ground-source heat pump

Heating and cooling are holdouts in decarbonization and ripe for revolution.

Seeking to do for home heating systems what SolarCity did for solar panels, a new company called Dandelion hopes to popularize decades-old, energy-efficient heating and cooling technology.

So-called “ground-source heat pumps” or “geothermal heat pumps” have been used for decades to warm and cool homes, especially in colder climates where expensive fuel oil is burned for warmth. The pumps use the relatively stable temperature of the Earth below the frost line to pull up and push down heat using pipes filled with a water/antifreeze solution (or food-grade propylene glycol, in Dandelion's case). Although ground-source heat is an old and proven technology, Dandelion says it has made a few advances to the installation process and business model that will make these systems a more attractive proposition for homeowners.

This is important because heating is still a sector of the global economy that relies heavily on burning fossil fuels, and cooling has a similar problem—running an air conditioning unit is really energy-intensive. In the summer, ACs represent considerable load that utilities have to plan for, usually with fossil fuel-burning plants. (Ground-source heat pumps require electricity, too, but we’ll get to that below.)

How does a ground-source heat pump work?

At relatively shallow depths in the Northern Hemisphere, soil tends to maintain temperatures equivalent to the mean annual air temperature above it (between 50 degrees Fahrenheit and 60 degrees Fahrenheit, according to the Department of Energy) year-round. Seasonal temperature variations are limited. So ground-source heat pump installers place solution-filled pipes underground either horizontally or vertically.

With the help of a heat pump, the solution that circulates in the pipes transfers heat from the ground to the building in the winter. During the summer, the solution forces heat out of the building and underground. According to a 2007 paper (PDF) in Environmental Research Letters, ground-source heat pumps can “provide heating using 25 to 30 percent of the energy consumed by even the most efficient conventional alternatives.”

There are drawbacks, of course. Installing the right ground-source heat pump technology is important—the details of the installation depend on the location of the home, property size, soil composition, and other conditions. Since heat pumps need some amount of electricity to operate, their greenhouse gas-avoiding properties depend on how much renewable energy your local utility uses, too. And the Environmental Research Letters paper points out that there are concerns that the energy used to power some ground-source heat pumps could have higher system-wide emissions than keeping a newer, high-efficiency furnace. So not every household needs one of these immediately.

Where does Dandelion fit in?

Dandelion claims that it has simplified the variables that go into a household’s decision to get a heat pump. The company grew out of Alphabet’s moonshot lab, formerly Google X, which has poured money into research that advanced projects like self-driving cars (Waymo), head-mounted mobile computers (Google Glass), and healthcare diagnostics (Verily).

Ars spoke to Dandelion’s CTO, James Quazi, about the project. Quazi said that Dandelion is only installing two-stage heat pumps right now—a relatively old technology compared to variable-frequency heat pumps that can modulate the heating and cooling work done by the pump’s compressor. But eschewing more cutting-edge technology for a pared-down technology that Quazi called “battle-tested” could help Dandelion keep costs down. After all, being able to show that ground-source heating offers economic savings is a priority for the company.

Specifically, Dandelion’s system uses a heat pump with a heat exchanger attached to one or two 400ft pipes that are buried vertically (yes, vertically) in one or two four-inch-wide boreholes drilled into your lawn. (“500 [feet] is generally the max you’d want to go, and further requires mining permits,” Quazi said.)

The pipes are filled with a mixture of water and propylene glycol, which captures the relative warmth of the surrounding earth. That mixture is then pumped up to a heat exchanger, where it lends that low-grade heat to a refrigerant, which is sent through a compressor to bring the heat up to 134 degrees Fahrenheit—a temperature that could actually warm a house.

One thing that’s new is how Dandelion drills those boreholes. “Generally, well-drillers use existing equipment,” Quazi told Ars, often using mining drills that produce six-inch holes in the ground. The installers then insert two, 1.25-inch pipes, connected at the bottom by a U-shaped pipe. But you don’t need a six-inch hole for little more than 2.5-inches of piping. Instead, Dandelion is retooling the traditional machinery to only drill a four-inch hole, which it claims reduces the amount of debris that needs to be hauled away and makes the drilling process more economical.

Additionally, the company said it has purchased some custom drilling machinery that will come complete with modifications specific to drilling in upstate New York, where Dandelion will be offering its first installs. In that area, before you hit rock, you’ll encounter some amount of what Quazi calls “unconsolidated soil.” In a traditional ground-source heat pump installation, that soil needs to be reinforced by steel tubing called casing.

Installing the casing makes vertical ground-source heat pumps vary widely in price, because drillers are never sure how much each project will need until the project is underway. This causes problems for customers who want a simple installation quote. Instead, Quazi said, Dandelion will use resonance sonic drill heads to liquify the earth in the drill path. This will allow the company to install up to 60 feet of casing “in about 10 minutes.”

A local endeavor

Quazi said many of his team members got started working for SolarCity, so they’re trying to adopt a business model similar to the one that helped that company become one of the leading residential solar installers in the US. That is: target a market where the economic and environmental savings are obvious, and scale out from there.

For ground-source heat pumps, that market is upstate New York. There, you’ll sometimes find extreme weather, and many houses depend on expensive fuel oil or propane for heating. Dandelion will be targeting homes of a certain size (“mega-mansions are not our target market,” Quazi said), and the company will give preference to homes that are heated and cooled with forced air, which is compatible with its system.

Additionally, New York has an abundance of greenhouse gas-free nuclear energy and renewable hydroelectric generators serving its grids. Using electricity to power a ground-source heat pump isn’t necessarily giving up fossil fuels locally just to export those emissions to the power station (although natural gas-fired generators do still play a big role in New York).

Quazi was frank about the fact that a Dandelion system isn’t going to offer savings for all homes—he said if you heat your house with natural gas, the system isn’t going to pay for itself due to natural gas being so cheap.

But if you do qualify, Quazi says Dandelion has standardized the installation so a system costs about $20,000 cash, or the company can offer a payment plan to make the install about $150 a month.

As with everything these days, the system also comes with a software end. Sensors are installed throughout the system so that the company can figure out when and where maintenance needs to be done. Analytics will also show the customer how much money they’re saving, and Quazi said that, by gathering data, Dandelion will be able to do predictive fault detection, so it can predict a component will fail before it actually does.

For now, the company is working on building a small backlog of a few dozen qualified customers who would see the most benefit from such a system. Then, Quazi told Ars, installations should begin around late September. After those installations, the company plans to take a break in late 2017/early 2018 to regroup and focus again on sales and marketing before proceeding with new installations later in the year.

If that doesn’t work for you, more traditional geothermal companies have been quietly expanding in the last several years, as well. According to a report compiled by Navigant Research for the business association Advanced Energy Economy, revenue from the sales and installation of geothermal heat pumps in the US has grown steadily in the past six years, “rising from $93.6 million in 2011 to $154.3 million in 2016, with an increase of six percent from 2015 ($145.1 million) to 2016.” Dandelion hopes that those increases grow even more in 2017.

Source

Understanding Medical & Laboratory Refrigeration

scservicess@gmail.com (SHAH) — Wed, 11 Oct 2017 07:53:00 +0000

What To Know When Choosing a Medical Refrigerator

When it comes to refrigeration, every facility has its own unique storage needs. Research laboratories may need to hold critical biological samples at a steady temperature or risk compromising a timely study, while some medical clinics may just need to keep ice packs on hand for patients with muscle pain.
Navigating the industry of scientific, medical, and laboratory refrigeration can be a daunting task. For many, the temptation to just purchase an inexpensive "dorm fridge" off the floor of a chain store is an easy solution. That decision, however, can be extremely dangerous and ultimately, far more expensive than investing in a quality appliance specifically engineered for the scientific industry’s storage needs. Temperature fluctuation can destroy the effectiveness of vaccines, meaning that a $199 dormitory refrigerator now has a much higher cost when you consider the expenses of the potentially life-saving materials being stored.

All-Refrigerator, All-Freezer, Or Refrigerator-Freezer?

One of the key differences in medical or laboratory refrigeration and household refrigeration comes down to the freezer. While most residential refrigerators include a freezer compartment, the CDC strongly discourages the use of combination refrigerator-freezers for any kind of vaccine storage. The same applies to any sort of laboratory refrigeration needs.

Refrigerator-freezers, whether they are full-sized frost-free units or compact dorm style models, are not designed with an eye towards temperature stability. In studies conducted by the CDC, dorm style units experienced as high as 5ºC temperature fluctuations from the midpoint. These single compressor units also tend to have much wider temperature gradients in the interior, meaning there is simply no “safe” place to keep the more sensitive items. Household refrigerator-freezers rarely allow the user to independently control the temperature of each compartment.

Most manufacturers that specialize in vaccine refrigeration offer all-refrigerators (or freezerless refrigerators) and all-freezers in place of these combination units. While some refrigerator-freezer units are perfectly suitable to keep staff items, beverages, and ice packs, they are not recommended for any kind of vaccine storage. It is also a bad idea to store both staff items (such as lunch and snacks) in the same unit used for vaccines because community refrigerators will undoubtedly experience more traffic. Every time the door is opened, items inside are exposed to ambient temperature. Over time, this can harm interior contents.

If you require both refrigeration and freezer temperatures for storage, consider stackable units or opting for slimmer side-by-side sets. Medical refrigeration is often offered in slimmer sizes to help accommodate these needs.

Size & Capacity

Obviously, you don’t want to choose a refrigerator too large for its setting or too small to store what it needs. At the same time, knowing how much storage will be needed is a key factor in choosing a medical refrigerator. Why? Because how much you stock the unit can help or hurt its temperature performance.

All refrigerators, whether storing vaccines or groceries, work best when loaded between 30 and 80%. An empty refrigerator with no load or a mere water bottle will experience large temperature fluctuations from the top of the unit to the bottom. If a unit is stuffed with too much content, air will not circulate properly, leading to cold and hot spots that can damage stored materials.

Always have a realistic estimation of how much capacity is needed when choosing a laboratory refrigerator.

Placement

Most refrigerators and freezers are generally designed for either built-in (or “zero clearance”) installation or freestanding use. If a refrigerator is going to be placed under a counter and surrounded by cabinets on either side, it must be designed and constructed for built-in installation. This usually means there is a fan that pushes air out the front (typically located in the kickplate).

Freestanding refrigerators do not usually include exterior fans. As a result, installing one under a counter with little ventilation will compromise its performance, as the side walls or rear can overheat. When choosing a medical refrigerator, always determine how much space you will need around it. Built-in capable units generally come at a higher price, but it’s worth the investment if it ultimately leads to safer cold storage in your institution.

Temperature Requirements

While there is no universal temperature setting for all vaccines or biological samples, it is always advised that any kind of medical refrigerator stay within 2 to 8ºC. Within that temperature range, most units will still experience minor temperature swings. For more advanced medical refrigerators, that swing should be no higher than 2ºC outside the thermostat set point.

Medical or laboratory freezers have different requirements depending on what they are storing. Ultra low laboratory freezers are generally classified by their temperature, with units that can reach between -45º and -85ºC. Other temperature classes include -35º, -30º, and -25ºC, while more standard freezers run between -10º and -20ºC. As you can probably imagine, it is vital to know what temperature requirements the items you will be storing have before purchasing a clinical grade freezer. Vaccines, biological samples, plasma, and other sensitive material have unique temperature needs, and it is best to know the details before making a decision.

Shelving

When it comes to the shelving systems inside medical refrigerators, the key is to promote proper airflow. While glass shelves tend to be more popular with residential customers for their easy cleanability, they are not recommended for medical storage because the solid surface can impede cooling circulation. Instead, look for a medical refrigerator that includes wire shelves, or shelves that are perforated with ventilation holes.

Some vaccine refrigerators are built with interior drawers that have solid fronts in order to help shield stored contents from ambient temperature when the door is opened. In that case, the drawers may be constructed from wire or installed with added space in the rear to allow full air circulation. These kinds of bins or baskets are recommended by the CDC to help ensure better organization and air circulation within the pharmacy grade refrigerator.

Another case where medical refrigerators differ from household units can be found in the door shelves, or usual lack thereof. Because door shelves are constantly exposed to ambient temperature, proper medical refrigerators will have flat door liners in place of door racks. General purpose or lighter medical refrigerators sometimes include door racks, but it is never recommended to store any sensitive material in that space. Instead, put water bottles or gel packs on the door shelves to help stabilize interior temperature.

Temperature Monitoring

Once you have selected a refrigerator designed to medical standards, it is important to make sure it is actually performing to these standards. Monitoring the temperature is vital to ensuring that your refrigerator is protecting, and not damaging its contents.

All scientific refrigerators should include a temperature readout on the outside of the unit. Note that this is not the same as having a digital temperature control outside the unit; a thermostat controls the temperature and generally shows a readout of what temperature has been set, while a thermometer (ideally, a NIST calibrated thermometer) will provide a more accurate display of the temperature inside the unit. The CDC recommends using a digital thermometer that has its probe placed in a glycol-filled bottle, as opposed to other fluid-filled bio-safe liquid thermometers, food thermometers, or household mercury thermometers. Certified thermometers will include a Certificate of Traceability to prove that the thermometer has been calibrated to a recognized standard.

For more specific and longer-term temperature monitoring, facilities should record temperature via a data logger. Many state laws now require automated temperature monitoring in hospital refrigeration. Depending on your needs, you can find a variety of temperature loggers that will work with your system. Rather than assigning a staff member to take regular temperature readings from a thermometer, data loggers record interior temperature at user-set time intervals. USB based loggers save the information to a thumb drive and allow users to view the temperature performance via spreadsheets or charts, while stand-alone loggers have smaller storage and record to their own system. Some more advanced data loggers can interact with smart phones or wireless connections and can include temperature alarms and notifications.

Temperature Alerts

While logging temperature is crucial, knowing if and when a refrigerator goes out of its required temperature range is even more vital to acting fast and protecting stored contents, especially when dealing with sensitive, expensive, and potentially life-saving vaccines. Many medical refrigerators will include audio temperature alarms that will sound if the unit rises or falls out of a pre-set temperature range. Depending on your needs, more advanced alarms can notify staff of a temperature issue via text message or email.

Additional Features

Now that we’ve covered the basics of what you will need in a laboratory refrigerator, here are a few additional features that can help your facility protect its stored items:

Hospital grade cords: Standard refrigerator plugs are usually three-pronged and stronger than smaller electronics, but for added safety, many state and local authorities specify a hospital grade cord with a ‘green dot’ plug. These cords are designed for more durability, meaning they will not become unplugged from the wall socket easily.

Self-closing doors: The busier a facility, the higher the chance a staff member may walk away from a refrigerator without thinking to check that the door closed properly. Self-closing door mechanisms are one solution to this problem. Leaving a door opened can obviously disrupt the interior temperature and also confuse the defrosting cycle. Self-closing doors help prevent this.

Open door alarms: Another solution to accidental open doors is to have an alarm installed that will sound if the door is left open, usually for over one or two minutes. While most medical refrigerators will already include a temperature alarm, it’s certainly better to catch the problem before it disrupts the interior to the point that sounds that alarm.

Locks: Most institutional refrigerators come standard with keyed locks to offer more security to stored items. Some states and governing bodies require certain pharmaceuticals be kept in locking refrigerators, or alternatively, in locking compartments or refrigerator lock boxes located inside the refrigerator. Locks can use a standard key, combination lock, or digital keypad. Some facilities prefer keypad locks or combination locks because staff doesn’t have to worry about keeping track of a key. This also makes it easier to handle staff transitions. Instead of redistributing easily misplaced keys, staff can instead change the access code.

Conclusion

As you can see, there are many factors to consider before specifying and choosing the right refrigerator or freezer for your facility. Improper storage conditions can lead to costly losses. Take some time to understand exactly what your storage needs are before committing expensive, potentially life-saving materials to their new home.

Thanks: http://www.accucold.com/understandingmedicalrefrigeration

Cooling Collar

scservicess@gmail.com (SHAH) — Mon, 06 Feb 2017 03:03:00 +0000

Meet CoolWare Personal Cooling System, a special system that beats the heat when you're in a hot place with no air conditioning.

The device is made of anodized aluminum and blows water-cooled air. It has 2 refillable chambers within the arms. The latter has space for 57 grams of water that is used to cool air brought in from the front and then sent out into the back of the user's neck.

A single AA battery is required to power the built-in motorized fan. The rear unit of the device has 2 power settings that the user can select.

In addition, there are 2 padded neck cushions manufactured using anti-bacterial fabric. These cushions ensure that the users benefits from a comfortable wear on the neck.

The user will have to refill the water reservoirs every 2 to 4 hours (water consumption depends on the temperature of the environment), reports 7 Gadgets.

Amazing solar-powered fridge

scservicess@gmail.com (SHAH) — Thu, 27 Oct 2016 03:39:00 +0000

It's the kind of simple yet brilliant invention that would have the tycoons of Dragons' Den salivating with excitement.
Not only is the fridge solar powered, it can also be built from household materials - making it ideal for the Third World.
Emily Cummins, 21, came up with the idea while working on a school project in her grandfather's potting shed. The fridge is now improving the lives of thousands of poverty-stricken Africans.

And Miss Cummins hopes to patent a more sophisticated portable model for use in transporting medical supplies around hot countries.
From the age of four, when she was given a hammer as a gift, Miss Cummins has spent much of her spare time making things out of ordinary materials.
She has won awards for a toothpaste squeezer for arthritis sufferers and for a water-carrying device, again for Third World use.

Her 'sustainable' fridge works through evaporation and can be used to keep perishable goods such as milk and meat cool for days.
Without using any power, temperatures stay at around 6c.
The fridge comprises two cylinders - one inside the other. The inner cylinder is made from metal but the outer cylinder can be made from anything to hand, including wood and plastic.
Miss Cummins, from Keighley, West Yorkshire, said: 'A fridge is something that people can't seem to live without.
'I wanted to keep it really simple and so I set about researching how we cooled things years ago. The simplest method of cooling something could be seen when you look at how we cool biologically - through sweating or evaporation.
'That idea led me to the design and the fridge was born.'

After her A-levels she spent five months of her gap year in Africa, perfecting and demonstrating her product. In Namibia she became known as 'The Fridge Lady'. Miss Cummins returned to the UK to start a business management course at Leeds University.
She had been refused a place on an engineering course because, to her dismay, she didn't have the correct qualifications.
Last year she met the Queen at Buckingham Palace after being invited to a prestigious women in business event.

Thanks Dailymail

Home Made

scservicess@gmail.com (SHAH) — Wed, 17 Aug 2016 06:38:00 +0000

How to Diagnose Refrigerator Problems

scservicess@gmail.com (SHAH) — Thu, 07 Jul 2016 04:41:00 +0000

Sometimes you notice there's something wrong with your appliance right away. Maybe the light in your refrigerator won't turn on or your food isn't staying cold enough. You might not know if its necessary to call a professional or if its something you can easily fix yourself. Diagnosing the problem yourself can be the difference between a quick fix and an expensive, unnecessary

Problem	Solution
Refrigerator Won't Turn On	Check the outlet and breaker Try resetting the circuit board
Refrigerator is Not Cooling	Check the temperature gauge Check for airflow and overheating
Refrigerator is Not Getting Cold Enough	Check the door seals
Refrigerator is Constantly Running	Defrost the freezer Check the door seals
Refrigerator is Leaking	Clean the drain pan

1

Check that the power cord is plugged in all the way. Pull out the refrigerator if needed and press the plug firmly into the outlet. Check your appliance's electrical cord for damage. Any exposed wire, kinks or cuts in the cord might make the appliance malfunction. If this is the case, do not use the cord and contact a repairman.
2

Remove an extension cord if you were using one between the refrigerator's main cord and the outlet. The extension cord may be damaged or faulty. Plug the refrigerator directly into the outlet. If this solves the problem, replace the faulty extension cord.^[1]
spaceplay / pause

escstop

ffullscreen

shift + ←→slower / faster (latest Chrome and Safari)

↑↓volume

mmute

←→seek

. seek to previous

12…6 seek to 10%, 20%, …60%

to Diagnose Refrigerator Problems

3

Try another appliance in close proximity to the refrigerator. Plug the other appliance into the same outlet that your refrigerator was plugged into. If that appliance also does not work, check your fuse or circuit breaker box. You might have a blown fuse or tripped breaker.
4

Try plugging the refrigerator into a different outlet. If this solves the problem, then the problem is with the outlet. Check the current and voltage of the outlet with a multimeter and voltage tester. If you do not know how to work these tools, contact a professional repair technician or electrician.
spaceplay / pause

escstop

ffullscreen

shift + ←→slower / faster (latest Chrome and Safari)

↑↓volume

mmute

←→seek

. seek to previous

12…6 seek to 10%, 20%, …60%

to Diagnose Refrigerator Problems

5

Try leaving it unplugged for a while, then plugging it back in. This may reset the circuit board (like rebooting a computer or a cell phone). By leaving it unplugged, you allow capacitors to lose any charge they may be holding.

Method2
Diagnosing if Only the Light Works

1
Check your temperature gauge inside the appliance. If the dial was bumped, it could have made it too warm for the refrigerator to turn on. It's important to check both the refrigerator and the freezer temperature settings, because the refrigerator gets its cold from the freezer. A problem with the freezer setting will affect the refrigerator as well.
- It should be set between 37 and 40º F (3-4ºC) for the refrigerator and between 0-5ºF (-15 to -18ºC) for the freezer.
2

Make sure there's proper airflow around the appliance. Check the space between the walls and the appliance. There should be a 3-inch (76.2 mm) gap around the sides of the appliance and at least a 1-inch (25.4 mm) gap at the top. This provides airflow needed for the machine to function.^[2]
3

Clean the condenser coils with a vacuum or brush. This part helps dissipate heat that could make the appliance act funny. This cleaning should be done with the appliance turned off. You should clean rear-mounted coils once a year, and floor coils twice a year.^[3]
4
Test for overheating and continuity. Unplug the refrigerator for 2 hours and then plug it back in. If it starts running "normally" again, the compressor is overheating and it should be checked by a repair technician. Use a multimeter to test each component for continuity. These include the temperature control, the evaporator fan, the defrost timer, the overload protector and the compressor motor.
- You may have to consult your owner's manual for the locations of the components. If a part does not have continuity, it is faulty and will need to be replaced.

Method3
Investigating a Refrigerator That Isn't Cold Enough

1
Check your temperature gauge inside the appliance. The dial could have been bumped, raising the refrigerator's temperature. It's important to check both the refrigerator and the freezer temperature settings, because the refrigerator gets its cold from the freezer. A problem with the freezer setting will affect the refrigerator as well.
- It should be set between 37 and 40º F (3-4ºC) for the refrigerator and between 0-5ºF (-15 to -18ºC) for the freezer.
2

Inspect the vents. Check the vents between the freezer and refrigerator and the drain tube for debris and ice. Remove debris if needed. This obstruction could be your problem.^[4]
3
Test your door seals. Place a piece of paper between the seals and the appliance. Close the door and pull out the paper. You should feel tension if the seals are functioning properly.
- Repeat the process all around the seals of the appliance. If there's no tension at any spot, the seals are starting to fail. You should also check for cracks and rigidity that could be causing a failing door seal.
4

Test the refrigerator components. Use a multimeter to test the continuity of the appliances various components. These include the door switches, the defrost heater and timer, and the evaporator fan. If any of these parts fail, they could be your problem.

Method4
Diagnosing a Refrigerator That Keeps Running

1

Wait a day to see if the problem solves itself. Several factors could cause your refrigerator to temporarily run continuously. If you live in a humid environment, just loaded the refrigerator, or recently adjusted its temperature, it might take a while for the refrigerator to cool completely. It could take 24 hours or possibly more for it to cool.
2

Defrost the freezer in case there's too much ice built up and clean your condenser coils. If there is a build of debris on your condenser coils, they won't be able to efficiently dissipate heat, and the refrigerator will have to constantly cool. If the defroster is faulty, then the evaporator coils will frost over, and the refrigerator will work harder to keep cool.
3

Test the door seal. The door of your refrigerator has a seal that prevents cool air from leaking out. If the seal is faulty, your refrigerator will have to constantly cool itself. Use a piece of paper to check for breaks in the seal. Close the door on the piece of paper and pull it out. There should be resistance when pulling the paper out, and if there isn't, a faulty door seal may be your problem. Repeat the test along the whole seal.
4

Clean the condenser coils with a vacuum or brush. This part helps dissipate heat, and if it's too dirty, the refrigerator will have to work harder to stay cool. This cleaning should be done with the appliance turned off. You should clean rear-mounted coils once a year, and floor coils twice a year.^[5]
5

Test the continuity of the refrigerator's various components. This will require using a multimeter on several of the refrigerator's components. These components include: the condenser fan, the overload protector, and the compressor relay and motor. A fault in any one of these components can cause the refrigerator to cycle improperly.
6

Test the outlet voltage. Use a multimeter to test the outlet voltage of the outlet that the refrigerator is plugged into. Do this only with the proper tools and safety measures. The voltage should test between 108 and 121 volts.

Method5
Determining Why a Refrigerator Leaks

1
Check the drain pan and tube. Water pooled outside the refrigerator might be caused by a dirty drain pan. Your drain pan should be cleaned about once a year. Water pooled inside the refrigerator might be caused by a clogged drain tube. Clean out a clogged drain tube by forcing a solution of water and baking soda or bleach through the tube with a basting syringe.
- The refrigerator should be turned off before attempting to clean the drain pan and tube.
2

Level the refrigerator. If your refrigerator is not level, things might not seal correctly, and the defrost drain might leak. The refrigerator was designed to operate correctly when level. Unplug the refrigerator, then place a level on top of the refrigerator. Check the back and front of the appliance and adjust the feet until it is level throughout.^[6]
3

Check the water filter. If the water filter is not fitted properly, water may leak out. After unplugging your refrigerator, remove and reinstall the water filter. Also check for cracks in the water filter head and housing. If there are damages, your filter head or housing will need to be replaced.

Technological innovations in heat pump systems

scservicess@gmail.com (SHAH) — Fri, 06 May 2016 06:23:00 +0000

PDF File

Leave your comments if you think it is helpful.

Electricity-free air conditioning

scservicess@gmail.com (SHAH) — Tue, 12 Apr 2016 17:37:00 +0000

A cool idea

New materials may change the way temperatures are regulated

AIR conditioning is a transformative technology. It has made the world’s torrid climes pleasanter to live in, and enabled the siesta-free working habits of the temperate regions to move closer to the equator. But cooling buildings takes a lot of energy. Heat must be pumped actively from their interiors to their exteriors. Fully 15% of the electricity used by buildings in the United States is devoted to this task. If an idea dreamed up by Aaswath Raman of Stanford University and his colleagues comes to fruition, that may change. Dr Raman has invented a way to encourage buildings to dump their heat without the need for pumps and compressors. Instead, they simply radiate it into outer space.

The idea, described in this week’s Nature, is both cunning and simple. Outer space is very cold (about 3°C above absolute zero) and very big, so it is the perfect heat sink. Earth radiates heat into it all the time. But this is compensated for by the heat the planet receives from the sun. To encourage one part of Earth’s surface (such as an individual building) to cool down, all you need do in principle is reflect the sunlight which falls on it back into space, while also encouraging as much radiative cooling from it as possible.

To try to turn principle into practice Dr Raman has made a material which reflects 97% of sunlight while itself radiating at a wavelength of between eight and 13 microns (or millionths of a metre), which is where the atmosphere is most transparent. Production of the material is made possible with modern manufacturing methods. It consists of four layers of silicon dioxide interspersed with three of hafnium dioxide. Each of these seven layers is of a different, precisely defined thickness, ranging from 13 to 688 nanometres (or billionths of a metre). It is backed by a layer of silver 200 nanometres thick, to act as a mirror.

The result, a sheet with a total thickness of less than two microns, is the photonic equivalent of a semiconductor: it does to light what a semiconductor does to electricity, namely manipulates its energy levels. Since, optically speaking, energy levels correspond to wavelengths, such an arrangement can be tweaked to reflect some wavelengths and preferentially emit others. And that, in choosing the layers’ pedantically exact dimensions, is just what Dr Raman and his colleagues have done.

Polythene plan
They worked out on a computer how thick those layers needed to be to reflect pretty much the entire solar spectrum while, at the same time, shedding infra-red light at the frequency which can most easily escape from Earth into outer space. And then they made it, to see if it works.

It does. Mounted on a silicon wafer to keep it flat, held in a specially designed box made of Mylar, polythene, polystyrene, acrylic and wood, to minimize the conduction of heat into it from its surroundings, and then left outside on a sunny, albeit rather wintry Californian day, the photonic sheet settled down to a temperature 4.9°C cooler than its surroundings. If it were thermally connected to those surroundings, rather than isolated from them, that temperature difference would disappear—but the result would be to cool the surroundings slightly.

Turning this discovery into a useful device will be a journey down a long road. Dr Raman and his colleagues have, however, taken the first step by working out that they should be able to replace the hafnium dioxide (which is expensive) with titanium dioxide (which is cheap). They will probably need to replace the silver, too—though the cost of silicon dioxide, also known as sand, is not so much of a problem.

The process will also have to be scaled up. And it will work only on those parts of a building (mainly the roof) that have a clear view of the sky, and thus of outer space, so it will not replace air conditioning completely. But the idea of even part of a building’s cooling system being electricity-free is an attractive one, so this may be the start of something really cool.

The economist

Refrigerator Odor Tips

scservicess@gmail.com (SHAH) — Thu, 10 Mar 2016 13:43:00 +0000

Odors in the refrigerator can come from many different sources. Spoiling food, spilled milk, open food. Often a really good cleaning out with an ammonia cleaner can help or with a baking soda & water mixture.

But, sometimes an odor can "permeate" into one of the plastic parts found inside the fridge, crisper pans, door liners, shelf supports. Even after you have found the spoiling food, removed it, cleaned the fridge up.....sometimes another plastic part will pick up this odor and continue to give the odor back off. A few things that can help with this type of an odor, place one these inside the fridge section:

box of baking soda
dish of coffee grounds
open slices of bread

I like using the bread trick to help remove odors. Just throw a slice or two onto one of the shelves in the fresh food compartment, leave the bread slice(s) in there for 12-24 hours -no longer- and then throw the bread out or I throw the bread outside for the birds to eat. When bread goes stale, it will suck in odors very well. Because the air inside the refrigerator is blown between both sections, this will help the fridge and freezer sections. Do this for about a week and you should notice a big change in the odor problem :-)

A really bad odor problem. Sometimes something like milk or juice is spilled inside the fridge. The liquid can run under the plastic edge breakers and get into the insulation. This can be very difficult to clean and may require a service call to have the old insulation removed and replaced with new insulation in that section.

WaterATM: Automated Water dispensing machine

scservicess@gmail.com (SHAH) — Sun, 28 Feb 2016 05:24:00 +0000

WaterATM’ is a user friendly automated water dispensing machine installed over filtration plants. It regulates usage of clean drinking water by using a user authentication mechanism. It provides technological innovations and help in saving clean and filtered water wastage which eventually impacts the community health.

The Challenge

In recent history, there has been much emphasis on low cost water purification technologies, however, not a lot of work has been done on automated monitoring and evaluation of such technologies. Recent advances in wireless sensors, alongside ubiquitous availability of mobile (GSM) networks in developing countries now make it possible to remotely and automatically monitor the quality of water being dispensed, thereby eliminating the human error/mischief element from the system. While organizations such as Sarvajal have used technologies to measure the use of the purification unit (as a proxy to measure water quality), to our knowledge, no organization has actually been able to remotely and automatically measure actual water quality metrics in real-time. Access to clean water is as important as access to water itself. The health and economic effects of polluted water are well documented. It leads to illness, ailment and even death. Mortality and morbidity impose costs on individuals and families which, above the direct costs of treatment and medicine, may include loss of earning and impaired productivity. The Supreme Court of Pakistan has declared, not only that the fundamental right to life includes a clean and healthy environment, but that access to unpolluted water is the right of every person wherever he lives.

Our Solution
Our proposed device, called Wrind, has two components: an automated water-dispensing unit, and a real-time remote water quality-monitoring unit. Given that Pakistan is an extremely water-scarce country, and water collection at water filtration plants is free of cost, we are working with the government to minimise water wastage and ensure quality. In order to do so, we are currently building a prototype of a 2 x 2 ft. water-dispensing unit which has three components: RFID authentication, a fluid flow meter to measure volume of water dispensed, and a solenoid activated valve to stop/start dispensing. Currently, we are able to accurately measure and dispense water, and also provide authentication via RFID tags, where the user data is stored on a local database. Moreover, we plan to add a two-SIM (one for backup) GSM component (GPRS/EDGE or SMS), where the log files from the Water Dispensing Unit can be pushed to a central database in real time. Also, we plan to design the user-interface of the device to especially cater to the needs of low-literate, less tech-savvy users.

Innovative Miniaturized Heat Pumps for Buildings

scservicess@gmail.com (SHAH) — Sat, 02 Jan 2016 03:33:00 +0000

Georgia Tech Research Corporation

Modular Thermal Hub for Building Heating, Cooling, and Water Heating

Program:

BEETIT

ARPA-E Award:

$2,399,765

Location:

Atlanta, GA

Project Term:

09/01/2010 to 06/30/2014

Project Status:

ALUMNI

Website:

www.gtrc.gatech.edu (link is external)

Technical Categories:

Building Efficiency

Critical Need:

Buildings currently account for 72% of the nation's electricity use and 40% of our carbon dioxide emissions each year, 5% of which comes directly from air conditioning. Current building cooling systems run on electricity and use synthetic fluids, leading to large energy consumption and greenhouse gas emissions. Thermally driven absorption heat pumps--which transfer heat energy from one location to another in a cooling and heating system--offer independence from electricity supply constraints because these technologies can be powered from the combustion of natural gas and solar and waste heat. In addition to providing efficient space cooling and heating, these heat pumps can heat water. However, the use of these technologies in residential buildings has been hindered by the lack of efficient and economical heat and mass exchangers.

Project Innovation + Advantages:

Georgia Tech is using innovative components and system design to develop a new type of absorption heat pump. Georgia Tech's new heat pumps are energy efficient, use refrigerants that do not emit greenhouse gases, and can run on energy from combustion, waste heat, or solar energy. Georgia Tech is leveraging enhancements to heat and mass transfer technology possible in micro-scale passages and removing hurdles to the use of heat-activated heat pumps that have existed for more than a century. Use of micro-scale passages allows for miniaturization of systems that can be packed as monolithic full-system packages or discrete, distributed components enabling integration into a variety of residential and commercial buildings. Compared to conventional heat pumps, Georgia Tech's design innovations will create an absorption heat pump that is much smaller, has higher energy efficiency, and can also be mass produced at a lower cost and assembly time. Georgia Tech received a separate award of up to $2,315,845 from the Department of the Navy to help decrease military fuel use.

Potential Impact:

If successful, Georgia Tech's absorption heat pump would reduce energy use in air conditioning by up to 50% compared to conventional systems.

Security:

Waste-heat or solar-heat-based air conditioning could reduce demand for fossil-fuel-based electricity and help strengthen U.S. energy security.

Environment:

Finding efficient and cost-effective ways to incorporate waste heat into cooling systems in addition to sources like solar and natural gas could decrease fossil-fuel-based electricity use and harmful emissions from coal-burning power plants.

Economy:

Widespread use of this technology could save consumers money on their energy bills by reducing the amount of energy required to cool homes and businesses.

Affordable Solar Powered Air Conditioning in a Neat Little Package is Finally Here

scservicess@gmail.com (SHAH) — Thu, 03 Dec 2015 18:38:00 +0000

Five percent of America's electricity is used for residential air conditioning, and it is considered now to be a necessity, not a luxury. It's usually needed most when the sun is shining, so as I have noted since 2006, Solar Powered Air Conditioning Just Makes Sense. For most of that time I have been looking at absorption units that run like a propane fridge, but I recently mused that perhaps it is time for a change in the way we think about this:

I am wondering if the solar powered air conditioner might not be in the end a small, high efficiency home with a small, high efficiency air conditioner powered by a big honking bank of photovoltaics, and be done with it.

I am not alone. Jamie Edens of Charleston, South Carolina read the post and wrote, telling me about his search for a solution to what he calls "the crux of our energy problem", all that coal that is being burned to generate the electricity to run that air conditioning. He also noted that there was a big movement everywhere to get off the grid, to stop paying so much money for electricity, but the real problem in doing so was the heavy load from air conditioning, and the poor efficiency of most units on the market.

After hearing a story of how truckers had seriously efficient air conditioners that could run on batteries while they slept, he started hanging out in truck equipment shows and discovered Kingtec Technologies, a big manufacturer of direct current air conditioners for the trucking and RV market. After building a prototype that was a minor hit on YouTube, and with the help of a local Kingtec distributor, Edens convinced the company to build a unit to his specifications.

They started with very efficient 48 volt DC unit that puts out 16,000 BTUs at 850 watts, giving it an Energy Efficiency Ratio (EER) of 18.8. (Martin Holladay explains that EER is the cooling capacity of the appliance (in Btu/h) at an outdoor temperature of 95°F divided by the current draw of the appliance in watts.)

They added a 45 amp solar charge controller and a 20 amp/hour battery as a buffer for when clouds block the sun. All you have to do is stick it in your window like a regular air conditioner, plug in a thousand watts of solar panels and it will run all day. Add more batteries or add a grid connection power supply and it will run all night. So for $2895 plus a thousand bucks worth of solar panels, you in business.

Edens has been to China and played with the prototype. Comparing it to his prototype, he writes:

The new air conditioner blow three times harder and has twice the BTU output. The efficiency are there and it is ready to change the world. It's not a toy- the beauty of this air conditioner is that all of the solar components are installed in the air conditioner and the engineering is done for you. All you need to do is plug in your solar panels and turn the unit on.... Air conditioning doesn't need to burden to the grid, our finances and contribute to global pollution. It can contribute a new start to clean things up and sustain the earth for the long run.

16,000 BTUs is not comparable to a typical home air conditioning unit; it's a big window unit that might normally condition 600 square feet. But if you combine it with an equally efficient home, you might have something here. After I mused about a photovoltaic powered AC unit earlier I wrote Martin Holladay at Green Building Advisor for his thoughts and he replied:

So, if you want to minimize your air conditioning bill, install low-solar-gain windows on your west (and perhaps east) walls, include wide roof overhangs, install deep attic insulation, minimize your air leakage, install an efficient air conditioner ... and then install PV, as much as you can afford. In other words, I agree with you.

Jamie Edens and Kingtec have built a neat little package that runs on a lot less than my "big honking bank of photovoltaics"; combined with a small home designed around its output (not a difficult thing to do) and you've got that holy grail I've been looking for: the effective and affordable solar powered air conditioner.

More at Kingtec Solar

LG LFX32945ST Door-in-Door Refrigerator Review

scservicess@gmail.com (SHAH) — Thu, 24 Sep 2015 20:48:00 +0000

The features, capacity, and performance are worth the price.

When LG introduced the door-in-door concept on the LFX31945ST refrigerator at CES in 2013, we weren't sure if customers would bite or balk at a trick door that lets users quickly get at condiments and drinks without opening up the whole fridge.

Since then, the market has spoken, and the design is apparently a hit. LG responded with a slew of new door-in-door fridges, a lineup that's topped by the LFX32945ST (MSRP $3,699.99). Compared to the similar LFX29945ST (MSRP $3,199.99) and the original LFX31945ST (MSRP $3,499.99), it's the best of the bunch... and also the most expensive.

At 33 cubic feet, the LFX32945ST has one of the largest advertised interiors on the market, but it the was impressive results in our lab tests that secured our recommendation. If you can swing the high price, we think this fridge is a perfect fit for a big family.

Design & Usability

A stainless steel Swiss Army fridge

LG LFX32945ST Door-in-Door Fridge

This high-performing, stainless behemoth is both spacious and user-friendly. View Larger

When it comes to high-end fridge design, this LG checks off almost every traditional box. There's a through-the-door ice and water dispenser that's tall enough for pitchers and vases, and controls that blend in with the stainless exterior.

On the inside, bright LEDs illuminate glass shelves with silver trim. Two spacious crispers and a slim middle drawer sit below a bevy of adjustable shelves. At the bottom, a fridge-wide Glide N’ Serve drawer offers three preset independent temperature settings. Two “hidden” compartments are built into the bottom wall of the fridge called the Slide N' Glide bins—LG must have gotten a discount on apostrophes—and they make for great child-height snack storage.

LG LFX32945ST Crispers

Crispers, temp drawers, slide n' glide compartments... The drawers, Duke, the drawers! View Larger

There's a slim icemaker on the left door, while the right plays host to this fridge’s main selling point: door-in-door storage. The six shelves on the right-hand door exist in an almost completely enclosed plastic casing. You can get at shelves normally by popping open a plastic flap on the inner portion of the unit with the main fridge door open normally, or you can open a thin secondary door triggered by pushing a button on the fridge’s handle. (Sound complicated? It's really not—just check out the little video for a demonstration.)

That same plastic casing I mentioned earlier? It serves as a buffer to keep more cold air inside the fridge compared to opening the regular doors. It means the fridge doesn't have to work as hard to cool down after it's been opened, which improves efficiency.

The drawback is that the six door-mounted shelves are completely fixed. Yes, they're carefully positioned so that you can fit anything from cups of yogurt and sticks of butter to gallons of juice and cans of soda. If you want to chill a bottle of Sauvignon Blanc, though, it’ll have to go into the fridge proper.

Performance & Features

It tested well, too.

When it comes to food preservation, our lab tests indicated no major flaws with the LFX32945ST. The crispers did a great job retaining moisture for fresh fruits and veggies. Freezer temperatures proved both cold and consistent, which should minimize the risk of freezer burn. It's good to know that a fridge this pricey holds up when it comes to food preservation as well as storage.

LG-LFX32945ST Freezer

Despite all the compartments in the fridge, the pull out freezer is actually quite straightforward. View Larger

LG LFX32945ST Icemaker

The door-mounted icemaker takes up minimal space while still serving up plenty of ice. View Larger

No fridge is perfect, but the LFX32945ST's downsides were minimal. For instance, we noticed some warm spots at the top of the fridge cavity, so be sure to store the most sensitive food items (like soft cheeses and defrosting meat) in the middle. It's really hard to keep temperatures even across a fridge cavity as large as this one, so we're willing to overlook this mild flaw.

Even if you're sold on style alone, there are two numbers you should know when buying a fridge: 0ºF and 41ºF. A freezer that fluctuates above 0ºF puts food at risk of nasty freezer burn, and bacterial growth might start when a fridge goes above 41ºF. Neither compartment in this LG got warm enough to put food at risk.

Chlorine Dispensers for Safe Water in Kenya

scservicess@gmail.com (SHAH) — Mon, 26 Jan 2015 17:01:00 +0000

Policy Issue:

Two million children die of diarrheal disease each year and contaminated water is often to blame. Treating water with chlorine could substantially reduce this toll. The most common approach to chlorination in areas without piped water infrastructure is to offer small bottles of chlorine for sale to consumers.However, chlorine use has been slow to catch on in this system. In this Kenyan study area, for example, less than 10% of households regularly use chlorine at a monthly cost of approximately US$0.30, despite several years of vigorous social marketing that has raised awareness about the product

Details of the Intervention:

Researchers examined free provision of dilute chlorine via a point-of-collection system, which includes a container to dispense the product placed at the water source, a local promoter to encourage the product’s use, and free provision of a supply of chlorine solution packed in bulk. This bulk supply dramatically reduces delivery costs relative to the retail approach, which requires packaging chlorine in small bottles, and relative to door-to- door distribution, which in addition significantly raises marketing costs. Hence, bulk distribution to water sources makes free provision more realistic. Additionally, this delivery method makes chlorine use very convenient. Users can treat drinking water when they collect it. The required agitation and wait time for chlorine-treated water are at least partially accomplished automatically during the walk home from the source. The source-based dilute chlorine disinfection approach to water treatment makes this act salient and public, in addition to making it cheaper and more convenient. The dispenser provides a daily visual reminder to households to treat their water at the moment when it is most salient—as water is collected—and maximizes the potential for learning, norm formation, and social network effects by making the dispenser public. Potential users can see others who use the dispenser, and they have the opportunity to ask questions; they will also know that others will see whether they use the dispenser

Results and Policy Implications:
Take-up of chlorine provided through dispensers dramatically exceeded take-up of chlorine for treating water for in-home use. When communities were randomly assigned to receive a promoter and a community dispenser, take-up was approximately 40% in the short run (three weeks) but climbed to more than 60% by the medium term (three to six months), representing 37- and 53-percentage point gains, respectively, compared to the communities that did not receive them.

In contrast to the take-up levels achieved with the dispensers, clinic-based coupon redemption started higher and dropped over time. More than 40% of households that were given coupons redeemed them 8 months into the program, but this figure fell to 20% by 12 months. This finding suggests that the success of the dispenser may be due not only to the zero price but also to the reduction in the psychic cost of remembering to treat water that is achieved by source-based treatment as well as other attributes, like the visual reminders. Although take-up rates are slightly lower than those achieved in some trials, the dispenser system relies far less on outside personal contact (e.g., from repeated household visits from enumerators) than do those approaches; hence, costs are significantly lower. The chlorine dispenser is extremely cost-effective, with a comparative study finding dispensers the most effective from a range of low cost approaches to reducing diarrhea.

The success of the chlorine dispensers at the proof-of-concept stage described here led to a concerted effort to scale the intervention up as a sustainable program. As of April 2014 over 1.8 million people were being served by chlorine dispensers, with plans to reach four million by the end of 2014.

The program has transitioned to Evidence Action, a new organization started with the support of IPA to scale evidence-based initiatives. More information can be found on their website here.

New system to reduce heating costs in cold climates

scservicess@gmail.com (SHAH) — Wed, 07 Jan 2015 12:33:00 +0000

WEST LAFAYETTE, Ind. - A new type of heat pump being developed at Purdue University could allow residents in cold climates to cut their heating bills in half.

The research, funded by the U.S. Department of Energy, builds on previous work that began about five years ago at Purdue's Ray W. Herrick Laboratories, said James Braun, a professor of mechanical engineering.

Heat pumps provide heating in winter and cooling in summer but are not efficient in extreme cold climates, such as Minneapolis winters.

"With this technology we can maintain the efficiency of the heat pump even when it gets pretty cold outside," said Eckhard Groll, a professor of mechanical engineering who is working on the project with Braun and W. Travis Horton, an assistant professor of civil engineering.

The innovation aims to improve efficiency in general but is especially practical for boosting performance in cold climates. The new heat pumps might be half as expensive to operate as heating technologies now used in cold regions where natural gas is unavailable and residents rely on electric heaters and liquid propane.

"We'll be able to extend the geographical range where heat pumps can apply," Horton said. "So this could open up a whole new market."

Researchers expect to complete a prototype by the end of the three-year, $1.3 million project. The research, which also involves three doctoral students, is a partnership with Emerson Climate Technologies Inc. and Carrier Corp. Emerson will work with researchers to create the prototype heat pump, and Carrier will integrate the new heat pump into a complete system.

Two research papers about the work will be presented during the 13th International Refrigeration and Air Conditioning Conference, the 20th International Compressor Engineering Conference and the first International High Performance Buildings Conference from July 12-15 at Purdue. The papers were written by mechanical engineering doctoral students Margaret Mathison and Ian Bell.

The new technology works by modifying the conventional vapor-compression cycle behind standard air conditioning and refrigeration.

"This could be a relatively simple modification to existing heat pumps, refrigeration and air conditioning systems," Braun said.

The standard vapor-compression cycle has four stages: refrigerant is compressed as a vapor, condenses into a liquid, expands to a mixture of liquid and vapor, and then evaporates.

The project will investigate two cooling approaches during the compression process. In one approach, relatively large amounts of oil are injected into the compressor to absorb heat generated throughout the compression stage. In the second approach, a mixture of liquid and vapor refrigerant from the expansion stage is injected at various points during compression to provide cooling. The added steps improve the compression process while also reducing energy losses due to friction in the expansion stage.

"Cooling the compressor keeps the refrigerant dense, and that's important because it takes less energy to compress something that's more dense," Braun said.

The researchers are developing a system for precisely controlling the flow of refrigerant from the evaporation stage into the compression stage using a series of small valves. A critical component of the new heat pump is a "scroll compressor," which uses a rotating, scroll-shaped mechanism to compress refrigerant. Domestic heat pumps normally use reciprocating compressors, in which a piston compresses refrigerant.

"You can't inject a liquid into a reciprocating compressor, whereas you can with a scroll compressor, which is uniquely suited for this modification," Groll said. "Also, an important part of our project will be to determine the efficiency of a machine that pumps liquid while also compressing gas, so there will be a lot of computational modeling involved."

The work grew out of research into the Ericsson cycle, an exotic refrigeration technology in which liquid is added to coolant as it is being compressed. The Ericson cycle, however, does not use the vapor-compression cycle because the gas never turns to liquid.

Refrigerator Defrost Cycle

scservicess@gmail.com (SHAH) — Mon, 08 Dec 2014 04:13:00 +0000

How a common frost free defrost cycle works and the main parts....

When the refrigerator is running ( cooling mode ) the defrost timer contacts prevents any power from getting to the defrost heater. When the defrost timer turns off the power to the compressor and fan motor(s) the power is then redirected to the defrost system. The defrost timer motor

Defrost thermostat:

During a defrost cycle, the defrost heater causes the metal alloy in the switch to warm and as it does it curls back and breaks the circuit. As the metal cools, it makes a closed circuit again. A defective thermostat can prevent the defrost heater from coming on or allow it to overheat which could result in heat damage or fire.

The defrost thermostat is located near the defrost heater and is wired in series. It is usually located at the back of a side by side freezer, behind the freezer back wall of a top freezer or under the floor. It will be necessary to remove obstructions such as the contents of the freezer, freezer shelves, icemaker and the inside rear or bottom panel of the freezer. At room temperature the defrost thermostat is an open circuit ( no continuity ) and when cooled down the defrost thermostat closes the circuit ( has full continuity ) to allow the defrost heater to come on.

Defrost timers:

The defrost timer is sometimes found behind the front grill of the refrigerator. It may also be found behind a cover plate inside the refrigerator or freezer, in the temperature control console, or behind the refrigerator near the compressor.

The timer is usually held in place with one or more screws. Remove the screws and gently pull the timer out far enough to disconnect the wiring connector.

Locate the timer switch and turn it clockwise until you hear it click. One click and the refrigerator shuts off = defrost mode, second click the compressor and fans come back on = run/cooling mode.

*Some defrost timers are a constant or continuous run timer, which means when ever the refrigerator is plugged in the defrost timer is powered up and running. Some defrost timers are an accumulative run timer, which means when the refrigerator is off the defrost timer is off and not running, when the refrigerator is running the defrost timer is running. This is also sometimes called a demand defrost. The power for the defrost timer goes through the cold control first on an accumulative defrost system. The timers are often the same but will be wired differently to get the different operations.

Defrost heater:

Test the heating element for continuity using a multimeter. Set the multimeter to the ohms setting X1. Place a probe on each terminal. The multimeter should display a reading somewhere between zero and infinity. Because of the number of different elements we cannot tell what your reading should be, but we can be certain of what it shouldn't be. If the reading is zero or infinity the heating element is definitely bad and should be replaced. Proper power ( careful!! ) to the heating element ( 110-120 volts AC ) and the defrost heater does not come on = bad defrost heater.

Some newer refrigerators have been using an electronic board instead of an mechanical defrost timer. The adaptive defrost control does the same job as the defrost timer ( shuts off the refrigerator cooling items and redirects the power to the defrost heater for the defrosting cycle, then redirects the power to the compressor and fans to come back on when the defrost cycle is over ). This adaptive defrost system is a bit different when testing, normally speaking if the defrost heater and defrost thermostat ohm ok, we replace the adaptive defrost board.