Ground Source Heat Pumps [Geothermal]

Standing Column Well Systems Overview

2010-11-24T09:10:00.000-05:00

Standing Column Well Systems

A Standing Column Well System, or SCW, is a hybrid of an open loop and closed loop configuration. It resembles an open loop because the water drawn from the well is used as the medium for heat exchange and an antifreeze solution is not needed. A SCW is similar to a closed loop in that it draws water from the well as the heat source, and returns it back to the same source after the heat has been extracted, which is also called the heat sink.[i]

In general, all of the water that is withdrawn from the well for heat extraction is returned to the well, allowing for the water level in the well to remain relatively stable. Some systems may be incorporate a bleed system, which allows for small amounts of water to be discharged into another well or other watercourse[ii]. The purpose of bleeding water from the system is to allow for more groundwater to flow into the well, bringing the overall water temperature closer to the design temperature for maximum system efficiency. The need for bleeding water may be required to prevent the well water from dropping to temperatures that may be harmful to the heat pump or to simply increase the heat exchange capacity.

[i] Rees, S.J., Spitler, J.D., Deng, Z., Orio, C.D., & Johnson, C.N. (2004). A study of geothermal heat pump and standing column well performance. American Society of Heating, Refrigeration, and Air-Conditioning Engineers Transactions: Research, 110, 3-13.

[ii] Rees, S.J., et al. (2004).

Water Energy Distributors, Inc.

2010-11-23T10:21:00.002-05:00

Please visit www.northeastgeo.com for more information about GSHPs. I believe that this company is one of the best in the area. They are committed to quality, education, and service. I have personally visited this company and was very much impressed!!!

Vermont Energy Atlas

2010-11-19T12:06:00.001-05:00

This is an excellent resource for Vermonters looking for information about alternative energy.

http://www.vtenergyatlas.com

FEEDBACK NEEDED

2010-11-18T09:03:00.000-05:00

As far a GSHPs what would you like to see discussed here? I am looking for what kind of information I could provide for you. I have lots of information about various aspects of GSHPs, but would appreciate a little input for those of you reading...

Weatherizing Your Home & Addressing Heat Loss

2010-11-17T10:58:00.004-05:00

The building envelope includes the components of the building such as the foundation, roof, walls, doors, and windows that separate the interior and exterior environments of a home. An inadequately sealed building envelope has a significant and direct effect on the efficiency of any installed heating and cooling components.

Heat loss is responsible for the most significant energy drain on a home. Direct heat loss, or air leakage, accounts for between 25% and 40% of the total energy used for heating and/or cooling in a typical residence[i]. Air gaps around window and door frames, gaps or cracks in bricks, siding, stucco and foundations, as well as electrical and gas service entrances are the most common sources of air leakage.

Heat loss through temperature differential is also a major source of energy drain on a home[ii]. Temperature differential occurs when different components of the building envelope conduct heat out, such as attics, walls, basements, crawl spaces, pipes, and roofs.

There are a few of do-it-yourself projects such as using weather-stripping, caulking, or a non-expanding spray foam to seal around window frames and exterior doors. Sealing attic hatches and insulating recessed light fixtures are additional methods of decreasing air leakage.

In many cases, a home energy audit, performed by a qualified technician, is the most beneficial means of obtaining a thorough and accurate measurement of air leakage in the home. An energy assessment will also determine if further insulation is necessary to prevent temperature differentials in the home. It is important to remember that proper air sealing should be addressed first and it could possibly negate the need for further insulation.

When considering insulation, the term R-Value is frequently used, it indicates the material’s resistance to heat flow. Factors affecting the R-Value include material, thickness, and density. The higher the R-Value, the greater the insulating effectiveness of the material.

Because 50% to 70% of the total energy consumption of a home is used for heating and cooling, preventing heat loss will decrease utility bills and increase personal comfort in the home.

It’s the Little Things Too!

ENERGY STAR® qualified Compact Fluorescent Light bulbs, or CFLs, use 66% to 75% less energy than incandescent bulbs. Despite the slightly higher cost of these bulbs, they last 6 to 10 times longer than traditional light bulbs, which can equate to around $42 in energy cost savings over the lifetime of just one CFL[iii].

Turning off lights when leaving a room and unplugging small appliances when not in use, will help to reduce your energy costs.

Plug small electronics, such as cell phone chargers, iPod chargers, and computer chargers into a power strip or surge protector. When not in use, turn off the surge protector, as these charging devices continue to consume electricity even when they are not in use.

Lowering the thermostat to 65° if no one is at home during the workday or at night before going to bed, could save you up to 10% on annual heating costs[iv].

Taking advantage of ENERGY STAR® qualified appliances and electronics may further decrease your energy consumption and lower your utility expenses.

Take advantage of rebates and incentives for energy efficient products. Find more information at: www.efficiencyvermont.com/pages/Residential/RebateCenter

[i] U.S. Environmental Protection Agency. (2000). Air sealing: Building envelope improvement (EPA 430-F-97-028).

[ii] Logan, K. (2010, November & December). The rise to retrofit. Green source: The magazine of sustainable design, 107-113.

[iii] Efficiency Vermont. (2010). About CFLs. Retrieved from http://newbulbintown.com/about

[iv] Efficiency Vermont. (2010). Energy-saving tips. Retrieved from www.efficiencyvermont.org/pages/Residential/SavingEnergy/EnergySavingTips

A Little More Info - Open Loops

2010-11-16T18:14:00.001-05:00

Open and Recycle Systems

Efficiency

Takes ~50 degreeF water from the well and utilizes in the system
The source temperature remains the unchanged throughout the year, therefore making it the most efficient system

Initial Cost

Used in areas where there is an abundant near-surface water supply
Utilizes relatively shallow wells, which decreases drilling costs for the consumer
Often in unconsolidated aquifers, loose gravel, and require steel/plastic casing to maintain borehole integrity

Geology

Requires a large quantity of water, which necessitates a responsible returno Wells in the Northeast
U.S. are often not able to provide the high flow rates required to use this method, so it is often NOT practical

Maintenance

Should have “liquids” checked every 1.5 to 2 years
Because it is used in conjunction with domestic water systems, it should be free of harmful bacteria, such as fecal coliform

The system should be checked periodically for these bacteria
Iron bacteria (gallionella) is not harmful to humans, but should be controlled to avoid occluded pipes

Regulatory

Federal and State regulations

o Permitting for water withdrawal and responsible return

o Return to navigable streams or rivers is also regulated

Thermal Stability

No change in subsurface geology because there is a constant drawing of water from the well and deposition in an alternate location

Senator Bernie Sanders on Geothermal

2010-11-16T16:41:00.000-05:00

The Science of GSHP

2010-11-14T22:57:00.000-05:00

Standing Column Well System

2010-11-14T22:55:00.000-05:00

2010-11-13T08:17:00.001-05:00

This broadcast is from North Carolina Public Radio. It's relatively short, just clarifies a few ideas that were not very clear in the VPR: Vermont Edition Podcast. Take a listen if you're interested in learning more.

http://wunc.org/tsot/archive/sot0710a08.mp3/view

2010-11-09T23:23:00.000-05:00

Geothermal HVAC

Energy Efficient Homes For Dummies

HVAC Simplified

VPR Broadcast from 4 October 2010

2010-11-09T21:21:00.000-05:00

Ground Source Heat Pumps are Discussed in this VPR Broadcast. Two industry professionals speak about the practicality and possibilities associated with GSHPs!!! Take a listen, I found it to be very informative. Let me know what you think...

http://www.vpr.net/news_detail/88926/

2010-11-05T22:59:00.000-04:00

The Chicago Metropolitan Agency for Planning (CMAP) identifies one of the three primary causal factors for the lack of retrofitting projects as lack of access to information. There is a significant need for a consolidated information source that is easy to navigate. Profits of individual companies should be set aside. Before companies can profit, the public awareness needs to increase dramatically. Without consumer education, the industry is doomed to obscurity!!!

Is this helpful information?

2010-11-04T09:15:00.001-04:00

Tax Exemptions/Credits, Loans and Other Financial Incentives

2010-10-31T20:01:00.000-04:00

Would you be more or less likely to purchase a Ground Source Heat Pump if you knew more about the financial incentives, such as tax credits, low interest loans, sales tax exemptions, etc.?

What is a Geothermal Heat Pump?

2010-10-28T11:48:00.002-04:00

A Geothermal Heat Pump, or GHP, is a system that has the ability to utilize energy and heat of the ground or groundwater to heat and/or cool your home. There are four primary configurations for GSPs: Closed-Loop Horizontal, Closed-Loop Vertical, Pond/Lake Loops, and Open-Loop.

Closed-Loop Horizontal Systems consist of a network of pipes, usually made of polyethylene, that are buried about 4-6 feet underground in a series of trenches. These pipes circulate a refrigerant or antifreeze solution, as the name indicates, this is a closed loop system, therefore, the refrigerant solution never comes in contact with the soil or with the groundwater. The solution is circulated through the actual pump system, which is located in the home. The pump circulates the refrigerant, which extracts heat from the ground surrounding the pipes. This heat is then distributed throughout the home. This process is reversed for cooling; the warm air is drawn out of the home and distributed into the ground. This configuration is ideal for new construction and it also is generally the most cost-effective configuration available.

Closed Loop Vertical Systems consist of a network of underground pipes at depths of 100-400 feet deep at intervals approximately 20 feet apart, the vertical pipes are all connected by a horizontal pipe (manifold). The process of heat extraction and distribution is the same as the Closed Loop Horizontal system, the only difference between the two is the layout of the pipe systems. This configuration is ideal for locations where the available land is not suitable for a horizontal system.

Pond/Lake Systems are used when there is an adequate body of water close to the home. A series of pipes are laid underground and placed approximately 8 feet under the surface (to avoid freezing). Verification that the water body has all of the necessary requirements to serve as a heat source is required.

Open Loop Systems utilize an existing well (and/or a drilled well) as a source for heat. However, unlike the closed loop systems, the open loop system uses the water from the well as the heat exchange fluid, instead of a refrigerant or antifreeze. This system often requires two wells, one for extraction and a second for return. This is a practical option given the right groundwater conditions. Groundwater codes and regulations must be taken into consideration with open loop systems.

The Introduction

2010-10-28T10:55:00.000-04:00

Whether you are planning on building a new home, or simply replacing or upgrading your current heating/cooling system, a Geothermal System (or Ground Source Heat Pump) may be a viable option for you. Despite the many claims, promises, and guarantees made by various distributors and contractors, geothermal heat pumps are not for everyone. Given the right combination of factors, geothermal systems have the ability to provide heating and cooling for your home at a higher efficiency and lower cost than most commonly used systems.