What is a ground source heat pump (GSHP)? A heat pump is an air conditioner that can cool in the summer and heat in the winter. The ground source part means that the heat removed from the building in the summer and the heat added to the building in the winter goes to and comes from the ground.

(Images: EnergySavers.gov)

What’s a renewable resource? Merriam Webster defines it as a resource “capable of being replaced by natural ecological cycles or sound management practices.” Sounds accurate to me!

So why the question?

Governments and utilities often provide financial incentives for equipment or system approaches that are more efficient than code minimum requirements. Those incentives are usually based on the efficiency difference (or energy use difference) between the efficient case and the code minimum case. For example, code might require a boiler that’s 84% efficient. If you install a 94% efficient boiler, you may get a rebate based on the 10% efficiency difference. In the case of renewables, like solar photovoltaics (PVs), the incentives are based solely on system cost since there is no “baseline” to compare to and those incentives are often much higher as a percentage of cost than an “efficiency upgrade” incentive.

Recently, I’ve been party to lot of conversation around this topic with many folks coming down on the side of GSHP systems being renewables. I don’t believe that they are.

Why Aren’t GSHPs renewables?

GSHP systems, because they use a compressor just like an air conditioner does, require an electrical input to function.  Very well designed systems will require one unit of energy input to move between three and five units of energy between the building and the ground. That’s an input of between 20% and 33% of the total energy transferred. If you want to go further, figure in the inefficiencies of generation and transmission and that percentage goes way up.

Where does that electrical energy come from? The US Energy Information Administration (EIA) notes that in 2010 89% of the electricity on the US grid came from fossil fuels, coal or nuclear power – none of which are renewable resources, and all of which have a significant environmental impact when extracted, used, and disposed of. The EIA predicts that number will be 84% in 2035; not much different 25 years later. So on average, currently 89% of the electrical power required to operate a GSHP system in the US is from non-renewable sources. Of course, your specific locale or building may have a different energy source profile which certainly warrants consideration. For example, I live in Burlington, Vermont. We’ve got a wood-chip power plant that has a maximum capacity large enough to power nearly the entire city according to the Burlington Electric Department. Realistically, it does not always operate at maximum capacity nor does it always burn wood chips, but assuming it provides just half the city’s needs on average means Burlington’s renewable power profile is significantly different than the nationwide average. Or, you may simply cover your entire building with PVs which will change that source profile as well.

Why THIS MATTERS

GSHP systems, when designed correctly, are typically more efficient that other, traditional systems because of the ground coupling.  Ground temperatures are relatively constant throughout the year and in cooling season are lower that the ambient air temperature and in heating season, higher. Rejecting heat to a cool medium and extracting it from a “warm” one makes for a more efficient refrigeration cycle. They’re also usually more expensive than traditional systems due to the ground coupling which typically entails drilling wells that can be 400 to 500 feet deep each (for certain types of systems), or other similar means of ground coupling – all of which require long lengths of pipe and site work that are both in excess of what a traditional system would require. But because they’re more efficient, utilities and governments will provide incentives to owners to help offset the added cost.

It’s true that GSHP systems are potentially more efficient, and they deserve to be incentivized, just like the example above of the more efficient boiler. But truly renewable energy sources – wind, solar, geothermal, hydro, biomass – should be incentivized at higher relative rates than more efficient systems that do not use renewables. A higher incentive for renewable energy sources will serve to further encourage their implementation.

Related

NREL on GSHP
Department of Energy on GSHPs

Sustainability – defined here as the responsible management of natural resources to create a more robust, independent and environmentally conscious organization – is a pursuit being explored by more and more companies. The challenge for many corporate leaders and managers is how to initiate change in their company’s culture. How do you create such a sea change authentically: something that won’t sound like a gimmick or start with a bang and fizzle out within a brief period of time? Over the years I have seen a pattern to the steps taken by clients who have been successful in creating a corporate culture of sustainability.

Step One: Obtain Managerial Backing

This step is critical – if you can’t sell it to upper management, there’s no use in proceeding. It will end up being undermined and employees will quickly realize it’s not genuine. If the leadership makes it a directive for the company, you will be able to embed sustainability in your corporate mission statement, create a plan and set goals. There are consultants that can help with this, but if you’re a small firm, this can be a manageable task of some research and a few brainstorming sessions with other interested people.

Step Two: Announce Your Vision to the World

This should happen through every medium at your disposal — through your company website (internal and external), e-newsletter, and professional blog. You want to get people talking – whether they are cynics or enthusiasts – and make the new vision synonymous with your company.

Step Three: Delegate Responsibility and Empower the People

The smallest step you can take with the largest, most enduring impact is to make the new priority of corporate sustainability part of an interested person’s job description. I worked with a small food manufacturer that advertised for a part-time “Environmental Coordinator” from within their workforce. A young, enthusiastic, albeit inexperienced person in the packing department was interested and it became a 20% position. Within a short time he had coordinated with a nearby paint company to take the empty 5-gallon containers the food manufacturer had been bringing to a recycler 30 miles away.

As a food manufacturer, they were not allowed to reuse the cleaned containers, and the paint company was buying brand new containers. This joint venture saved the food company the cost of recycling and the 60 mile round trip every week, the paint company got clean containers at a much lower cost, and the environmental cost of producing and disposing of the containers was averted.

It is important for the “Environmental Coordinator” to be empowered to identify opportunities within their department and bring it to a manager that has the authority to prioritize and enact the chosen ideas. It is also important for every person in the company to feel empowered to bring their ideas to these coordinators. This can be done in many ways – anonymous suggestion boxes, an internal website suggestion tab, or a whiteboard in the coordinator’s office – depending on the current culture of the company. It is also advantageous if an Environmental Coordinator can trade ideas and brainstorm with other coordinators on a regular basis. If there are multiple coordinators within one organization, the coordinators from each department could meet regularly to brainstorm, learn from each other and synergize their efforts (reducing costs, gaining support). One company I worked with started a multi-organizational environmental group. The Environmental Coordinators from six non-competing, like-minded companies met on a quarterly basis to trade ideas on issues such as recycling, environmentally friendly suppliers and efficient manufacturing ideas. (Vermont Businesses for Social Responsibility coordinates several such groups.)

Recurring Step: Keep People Informed

Announce your success stories, your current projects, ideas you’ve heard about, and relevant stories from other companies. These stories will reinforce the company’s commitment and celebrate your people. And these days many of these ideas are easy to track and quantify. For example, our company provides bus passes to all employees for free to encourage the use of mass transit for commuting. We can track the emissions savings by how many times an employee requests a new pass and how many miles of driving to work in a single-occupied vehicle this saves them. Our local school started a campaign to reduce the amount of printed material they created and found they don’t require recycling pick up as often – savings that are shown on their monthly overhead costs. Quantifying these savings is important in order to reinforce the significance of the new culture shift towards sustainability, empowering everyone from the CFO to the packer on the production line.

Be the change you want to see in the world

Word of mouth and cultural image are immensely powerful. People listen, judge and act in accordance with what they hear and see happening around them. Tell stories about your ideas and then share what you accomplished. These stories will paint a picture of what your company stands for and this picture will help to create the cultural shift you want to see.

Related articles

• How To Embed Sustainability Into Corporate Culture: A Cheat Sheet (Northern States Solar Services)
• Healthy corporate culture lets strategy execute. Amen. (mcnakblog.com)
• #CORPORATE CULTURE tweet (mcnakblog.com)
• Know thyself: Corporate culture begins with introspection (business.financialpost.com)

A coworker recently forwarded a link to a posting in the Environmental Leader by Kathy Miller, mentioning that it related to some of my blog posts. In How to Engage in Sustainability with Higher Purpose, Dr. Miller points out the importance of corporate vision to sustainability, and recognizes that engaging people increases their commitment to the business and its goals. These are recurring themes in my thinking.

Evolutionary Thinking

Over the past 30 years I’ve worked for a Fortune 500 company, mid-sized engineering consulting firms, a state agency, a non-profit and now my own energy consulting firm. After experiencing a variety of management approaches, I have pinpointed six principles for engaging people in their work and the larger mission of an organization.

1. Use an inclusive decision making process. People throughout the organization need to be part of the process for developing policies, budgets, schedules, products and communication.  Develop a well organized process to effectively identify appropriate stakeholders, ensure that relevant perspectives are considered and provide clear channels for review and feedback both initially and post implementation.  You want the process to clearly identify the individual who has the ultimate responsibility and authority for the decision.
2. Give the benefit of the doubt. A fundamental tenant of our legal system is innocent until proven otherwise.  Applying this same approach in the business world means we recognize that in almost all cases people have the right intentions, but mistakes happen.  When a corporate decision is made that negatively affects personnel, feedback needs to be heard and changes made, but affected individuals should not presume that they have been intentionally wronged.  Similarly, when an error is made in schedule, budget, work or communication, it should be viewed and treated as a mistake, not as an employee failing or intentionally undermining the effort.  Accusations, anger, and frustration cost money, time and productivity and have zero positive contribution to engagement or profits.
3. Recognize that work is, well, WORK. At times any job can be hard, boring, onerous, unrewarding, frustrating, or repetitive.  Workplaces need to recognize this, provide outlets and address issues when they arise.  A coworker recently shared her frustration at being required by a client to continue to use a process that is known to be dysfunctional. The issue has been raised and elevated several times over the three-year project, but nothing has changed.  It can be hard to hear another’s frustration and know that the solution is not in your grasp.  But if my response had been “it’s our job,” imagine how her frustration would only have grown.  Instead our discussion resulted in identification of some small benefits to the approach and a modified way of dealing with the negative result of the flawed process.  It wasn’t perfect, but my coworker felt heard and my sensitivity to the burden on the project team imposed by the problem increased.
4. Embrace work/life balance. As a consulting firm, Cx Associates is always looking to fill our new business pipeline, yet we have little control over the inflow of work.  When the inflow warrants new hires, finding qualified personnel can be difficult.  So, we often end up with more work than resources and people work overtime.  This is profitable but not sustainable.  While it is inevitable that people will need to put in extra hours, it is essential that people take breaks.  Flexible schedules and generous personal time policies support people in gaining balance.  Firms also need to ensure that people don’t just accumulate time off.  Adopting policies that limit carry-over and proactively work to get people to take time off makes sense for people and companies.
5. Share responsibility by sharing authority. I once worked for a client who was responsible for the development of a new ski area base lodge in Vermont.  He worked for a large NYC-based organization and even though he was smart, competent and good at his job, he could not make a single decision without being second guessed by “the powers that be.”  He left, his similarly competent replacement left and the project took twice as long as necessary to design and build.  To successfully engage people in taking responsibility, verify they have the necessary skills and knowledge, then give them the authority to make the decisions necessary to manage their work and support them in the process.
6. Create a respectful environment. When I started as an intern at Corning Glass Works, Amory Houghton approached my desk to say hello.  I addressed him as “Mr. Houghton” and he responded that I should call him “Amo.”  This was a clear statement to me that while he was the CEO and I was an intern, we were working together for the company.  I refer to people I work with as coworkers, not as employees.  While both terms are correct, reducing the verbal hierarchy shows respect for the individuals who contribute at many levels to the success of the organization.

Creating a workplace culture that values everyone takes time and practice.  No one gets it right all of the time, but if they get the benefit of the doubt, learning can take place with every miss and engagement will increase sustainably over time.

Project-specific energy efficiency baselines, where the starting point for building efficiency is adjusted based on knowledge from our past successes, will become the norm as the energy efficiency market becomes more sophisticated. You read it here first.

I make this prediction based on my onsite measurement and verification experience (M&V) and participation in baseline studies. Let’s examine three examples for a look forward at the efficiency planning landscape in years to come. Project-specific baseline issues apply to existing buildings that have received prior efficiency upgrades and to new buildings subject to increasingly stringent energy standards. Whether efficient systems are installed due to efficiency program incentives or changing attitudes toward responsible energy use, the use of accurate baselines is ultimately essential to successful projects.

Daylight Harvesting Controls in the Baseline for Efficient Lighting Upgrades

Energy efficient lighting savings are often based on ‘always on’ operating hours, however this may not actually be the case. Using an ‘always on’ point of reference can create inflated expectations of cost savings. Whether controlled manually by occupants, by code-required controls, or other automatic controls, when the lights are off, they are not saving energy compared to less efficient fixtures, or compared to a code‑maximum allowed lighting power density (LPD).

It is not unusual to find lighting controls already installed, such as daylight harvesting, occupancy sensors, and multilevel switching.  In fact, automatic lighting control for buildings larger than 5,000 square feet has been required by ASHRAE 90.1 since 1999, and with the adoption of ASHRAE/IES 90.1-2010 automatic lighting controls are even more stringent. In one real world M&V project it was found that the annual energy savings for an efficient lighting project was on the order of 150,000 kWh lower for the actual installed system than for a reference system that was always on. The lower run hours were due to a daylight dimming system that was standard practice for the building owner.

In this example, an ‘always on’ assumption overestimated the impact of the better lights. That said, the efficient fixtures saved a verified 1,630,596 kWh annually, even with the daylighting controls in place. Clearly the efficient fixtures had a substantial impact, however the absolute cost savings reduction over more years due to an incorrect baseline could be significant on a net present value basis. Using project specific baseline hours of operation is therefore essential to avoid possible perceptions of underperforming efficiency investments in the long term.

Productive next steps toward creating a culture of efficient buildings will depend on new benchmarks such as verified success and persistence of efficient measures. In the lighting example above, will the fixtures continue to be replaced with efficient products? It will become increasingly important to shift focus from initial implementation, which can be likened to ‘triage’ for many projects, to a more mature model of responsible energy use. This new model has an emphasis on design review, successful implementation, and ongoing commitment to preserving the energy efficiency infrastructure through real time energy use monitoring systems and continuous commissioning that compares historic use to current, and identifies and attacks upward trends in building energy use.

Variable Flow Fan Systems as Baseline for Outside Air Conservation Measures

In another real world example, fan system sizing in a variable speed integrated lab exhaust system resulted in underestimated fan energy savings by a factor of 200%. Variable speed laboratory exhaust systems are a common option used to satisfy code requirements when the total fume hood exhaust rate is 15,000 cubic feet per minute (cfm). Outside airflow is reduced based on the quantity of hoods in use, saving fan energy in addition to heating and cooling energy. However, the amount of fan energy saved depends on system sizing.

It is not unusual to find installed mechanical systems that are larger than needed, frequently running at part loads less than 50% of the original design due to differences between site conditions and conservative design assumptions. This means that the actual input power of the fan is in a lower range than expected, and fan energy savings are smaller than they would be for a more fully loaded system due to the fan system affinity laws for power and airflow.

‘Right sizing’  in variable speed systems maximizes savings compared with an oversized, partly loaded system. Regardless of whether the savings were smaller or larger than the original estimate, savings calculated based on variable speed baseline systems may be substantially different than expected unless the actual operating point brake horsepower of the baseline system, after balancing, is considered.

VFD in Constant Volume Applications

Savings based on nameplate motor horsepower, even if reduced by a factor to account for motor upsizing, has been shown in our M&V work to overestimate savings when VFDs (Variable Frequency Drives) are installed to permanently reduce the speed of a fan or pump to a lower-than-design constant speed. Future retrocommissioning savings for existing equipment may be significantly less than in the ‘old’ days when constant volume baselines based on the full design brake horsepower provided highly favorable financial justification. Energy savings calculations should be based on the actual operating brake horsepower after balancing of the baseline system.

The Future

Our successes in reducing energy use are paving the way toward a new vision of responsible resource utilization. By championing innovative design and controls implementation, and preserving our hard-won efficient infrastructure, our buildings can advance beyond a collection of efficient products and systems toward a built environment that embodies appropriate use of the Earth’s resources.

Building control systems rely on the information provided to them by the various sensors throughout the building. Sensors for temperature, light level, carbon dioxide (CO2), and enthalpy (or total energy content of air) are just a few examples. If the critical sensors in a building are inaccurate (that is, significantly out of calibration), the building will not work efficiently, costs will increase and comfort issues will result. Let’s look at how to calibrate your building control sensors, what to calibrate, and a few examples of why control sensor calibration is so important.

Proper Calibration Technique

To calibrate a sensor correctly, you need to use a test instrument that itself has been calibrated according to the standards of the National Institute of Standards and Technology (NIST). This ensures that the instrument is, in fact, accurate within a certain margin of error based on a standardized, repeatable test procedure. There is no use in calibrating one device to another if the baseline instrument hasn’t been properly calibrated itself.

What to Calibrate

You don’t need to calibrate all the sensors on a project by any means. Sensors that are locally adjustable by a user, like a digital thermostat, can be excluded if necessary. The user is going to find a number that’s comfortable so it doesn’t really matter if the T-stat says 72 degrees but it’s really 70 as long as the user is content. You do need to calibrate the critical sensors – those whose inputs are responsible for energy management decisions by the building’s control systems.

Examples of Critical Building Control Sensors

Take, for example, a CO2 sensor that controls ventilation to a conference room. I’ve personally calibrated CO2 sensors from reputable manufacturers that have been over 200 parts per million (PPM) off. I haven’t just seen this problem once or twice — I’ve come across miscalibrated sensors dozens of times in my experience. Building codes require minimum ventilation rates be provided to occupied spaces and measuring CO2 is a way of indirectly quantifying the amount of ventilation being delivered. Let’s assume a building code requires 20 cubic feet per minute per person (CFM/p) of ventilation. The corresponding space CO2 set point would be 930 PPM, assuming ambient CO2 of 400 PPM and office-type occupancy. If that CO2 sensor reads 200 PPM low, the resulting ventilation rate will be roughly 15 CFM/p, or 25% deficient. If it reads 200 PPM high, the resulting ventilation rate of approximately 32 CFM/p is 60% high with a commensurate increase in energy expenditure to condition that air.

Certainly, many sensors come out of the box within calibration, but each sensor has to be set up properly by the controls technician. Typically, you’ve got four choices – 4 to 20 mA (milliamps), 0 to 5 V (volts), 0 to 10 V, or 2 to 10 V. The technician has to make the right choice within his or her software. On a recent project I measured the return air relative humidity (RH) for an air handler to be 54%. The controls system was reading 27%. You guessed it – the sensor was set up in the software as a 0-10 V sensor when it was, in fact, a 0-5 V sensor. What’s the big deal? That sensor is used to calculate the return air enthalpy. It’s then compared to the outdoor air enthalpy and the controls system makes a decision on whether to recondition the return air (called recirculation) or get rid of it and use 100% outdoor air (called economizer mode). The one with the lower enthalpy wins. Had this set up error not been caught that unit would have spent many more hours in recirculation mode rather than economizer mode, with much lower realized energy savings than possible.

Why?

I’ve worked with commissioning providers and engineers alike who are proponents of skipping this critical step in verifying a building’s performance because of the perceived savings in fees associated with the time it will take to do the calibrations. In both the examples above, the time to calibrate each sensor is between 5 and 10 minutes. Typical calibration of all the critical sensors on a job site takes approximately one to two hours. Compare the annual savings potential with your or your consultants’ hourly rate and you can quickly see how cost-effective it is to calibrate your building’s critical sensors.

One of the biggest challenges in conducting a building commissioning design review is to get the designer to seriously consider a design review suggestion. Designers will naturally be defensive, as would any of us. Having been an HVAC designer myself, I know one of the designer’s biggest fears is seeing comments that make the designer “look bad” to the client (building owner).

Some Fundamentals

To avoid a defensive reaction and get serious consideration from a designer plan carefully for the way in which a design review comment will be presented; it’s really no different than having a sensitive discussion in a meeting or on the phone. Always maintain a positive and respectful tone. Avoid sounding too authoritative. And never, ever make the designer look bad.

A comment should state the issue clearly, then present a solution or opportunity. One of the best approaches is to present the issue and then offer a solution in a question format. A question format is highly effective and it is a non-threatening approach. Here’s an example: “The specs call for glass “stick” type piping thermometers, which are difficult to read in the field. Could easy to read, round dial-type thermometers be specified?”

“In My Opinion”

Using the phrase “in my opinion” as part of a review comment is ineffective. Opinions don’t matter; and besides, everybody has one. Opinions are subjective. But engineering is objective.

However, using the phrase “in our experience” carries much more weight. The experience of a commissioning (Cx) service provider is viable and valid. Relating problems encountered from other projects is informative and useful. A designer will seriously consider an experienced-based comment because most designers have minimal startup and field testing experience. Experience is more objective, thus much more acceptable.

Good Design Practice

Using the phrase “good design practice” is subjective and by itself is ineffective. Referencing “good design practice” in a comment works only if it can be supported with an authoritative document to support the otherwise subjective phrase.

Design Conflicts

It is not unusual to see blatant errors and conflicts in a design that has been poorly executed. A piping detail may seriously conflict with a control schematic diagram or the specifications, and you know the problem is fundamentally sloppy or careless design. In these cases, the use of review phrases in your comment solution such as “…as the design progresses”, “…as the design is finalized” or “…suggest reconciling conflicts when final checking occurs” can work very well. The phrase is non-threatening because the reviewer acknowledges final checking is part of the process and no one expects an error free design when the design is only partially completed.

Heavy Ammunition

It’s not uncommon for a designer to be less than familiar with a critical code or industry standard and often the design will reflect that lack of knowledge. Using a code or industry standard, as well as the specific chapter and verse to convince the designer almost always works. Cite the specifics, such as Section 6.5.4.1, ASHRAE Standard 90.1-2007, Energy Standard for Buildings Except Low-Rise Residential Buildings. Including a sentence or two of the exact code language in a review comments can be powerful.

Energy Efficiency Opportunities: Hidden Veins of Gold

There are very few designs which capture all of the possible efficiency opportunities.  Most designers are in a mindset focused on design day conditions — extreme winter and summer conditions — and little attention is applied to part load operation. Part load opportunities are where the real gold resides because systems operate at part load 99% of the time. But to convince the designer, one has to provide calculated energy and operational cost-saving figures. Such savings estimates can quickly and accurately be created using spreadsheets. A precise estimate is not necessary to “sell” the opportunity; an average annual estimate will usually suffice. The order of magnitude of the savings is what is really important.

Reducing operating costs demonstrates the value of building commissioning to the owner.

Could I be Wrong?

Always keep an open mind to the designer’s response to a comment. There is always the possibility you could be flat wrong. If you think about what you have learned with each new project — sometimes you’ll wonder how you have survived and avoided big trouble all these years without that new knowledge.

Your goal is to get the very best building possible for the building owner. Carefully planning how you present your commissioning design review comments to the designer will make it more likely your recommendations will be accepted — and that you, the designer, and the building owner will all feel successful at the conclusion of the project.

Related articles

• Why You Need a Design Review (buildingenergy.cx-associates.com)
• Building Retrocommissioning: What Is It and Why Should You Care? (buildingenergy.cx-associates.com)

PETM, or the Paleocene-Eocene Thermal Maximum, has been on my mind lately since Vermont is still recovering from the impacts of Hurricane Irene. While the direct impact of the storm was on relatively small numbers of people in a world of 7 billion humans, we in Vermont have a tight knit community. We feel each other’s pain.

For me, part of the flood’s impact was seeing what happened to our buildings. It is very clear that because we are not acting fast enough to reduce greenhouse gas emissions, we will increasingly need to adapt to a rapidly changing climate — including adapting our built structures. Which brings me back to PETM.

The Earth has been here before

National Geographic recently ran an article, Hothouse Earth about the Paleocene-Eocene Thermal Maximum (PETM), a period 56 million years ago when atmospheric CO2 levels were at 1,500 PPM.  “The PETM lasted more than 150,000 years, until the excess carbon was reabsorbed. It brought on drought, floods, insect plagues, and a few extinctions…. But there were no humans around 56 million years ago…”

The good news for me is that some forms of life on the planet survived and even flourished under those conditions. Since I often wake at night worried the human species may annihilate life on our planet, this has eased my stress, a little. Yet the rise in CO2 concentrations that lead to the PETM occurred over thousands of years — and now we are driving toward a rate of change that is likely to be about 10 times faster by releasing carbon sequestered beneath the earth during the Cretaceous period within just a few hundred years.

In the PETM

One noteworthy feature of the PETM was a sea level 220 feet above the current level. Another important aspect was the cycle between drought and extreme rain events. If we think the flooding we’ve seen this year — in Vermont alone we saw Lake Champlain set a record high and remain above flood stage for months in the spring after extensive flooding due to a late season heavy snowfall, plus exceptional flooding from Irene in the fall — it is likely to get worse.

Part of the solution?

Buildings in which we live and work must be redeveloped to survive extreme weather events while eliminating their contribution to climate change. Building energy resiliency means creating buildings that can operate when the grid is down and that contribute to the local environment by protecting the watershed, providing safe refuge during extreme weather and creating joy over the life of the building.

We can transform our built environment to offer the protection and benefits of passive survivability — but we need to change our current building practices quickly.

Everyone is talking about building retrocommissioning – they just don’t know it.  Retrocommissioning is the art of analyzing a building’s current performance and implementing measures to reduce the operating cost while improving the functionality of the building’s systems. (Commissioning is the term used to describe this process when it is applied to new buildings, so ‘retro-commissioning’ evolved as the term for when the building has been around a while.)

Building retrocommissioning includes engineering analyses designed to increase efficiency, lower operating cost, improve occupant comfort and decrease maintenance costs.

Retrocommissioning spans the spectrum from tweaking controls of the HVAC and lighting systems to physically analyzing the functionality of the mechanical systems. (Are the valves and dampers working? Are the systems piped correctly?). In the end, the building operates more smoothly, occupants are more comfortable, equipment maintenance problems are reduced and the building owner saves money.

A photo of a strainer installed upside down and backwards. Contractor told the owner he was “all set”.

Building owners, facility managers and businesses

Building owners, facility managers and businesses are interested in retrocommissioing because energy savings go directly towards the bottom line — reducing the cost of doing business. It makes you more competitive, allows you to invest in the business, increases your profit margin and offers protection from energy price fluctuations. It’s an exceptionally safe method of improving your business because it makes the company stronger from within, less dependent on outside influence.

Why are people talking?

People are talking about building retrocommissioning because the savings are potentially phenomenal. Existing buildings that haven’t been looked at for 5 years typically have “low-hanging fruit” that can easily save 5% on energy bills without a large investment. There is, for example, usually great potential for simply turning the lighting and HVAC controls down automatically when the building is unoccupied — for office buildings that can be as much as 70% of the year!

And that’s just the utility bill. Building retrocommissioning also reduces maintenance problems and occupant comfort complaints. A true retrocommissioning job includes a detailed analysis of the functionality of the HVAC system. Chillers, boilers, and air handling units typically get tweaked or retrofitted over the years to solve perceived problems but often times the “solutions” are Band-Aids — not true solutions to the problems. When the building needs change, systems are renovated accordingly, often without a big-picture view of how one renovation affects other, existing spaces. Over time, this leads to a system that does not perform as desired — leaving building occupants complaining and unproductive, maintenance people overworked and maintenance costs higher than necessary. These costs are avoidable by having an engineer analyze the systems and current building needs on a comprehensive level.

a CO₂ setpoint of 750 PPM — energy HOG! This unit serves an office space which should be set to 930 PPM (under the ventilation code to which it was built). That’s roughly 50% more OA CFM than necessary resulting in conditioning more OA than necessary. A perfect example of the proverbial “screwdriver fix”.

Realized savings

We regularly see savings for building owners of 18-27% from our retrocommissioning jobs. (This is for a complete building retrocommissioning job with a detailed analysis of the mechanical and lighting systems.) In addition to a financial return, retrocommissioning educates the building owner, facilities and maintenance staff on their mechanical and electrical systems so that they can operate and maintain their systems more efficiently.

As an owner, you expect a smooth performing building. Our economy and our business community need energy efficient buildings. Building retrocommissioning is a proven vehicle to achieve these expectations — so let’s all keep talking about it.

Related articles

• DOE Software Models Good Building Behavior (earthtechling.com)
• Retrocommissioning Energy Star Buildings, EPA

Efficient air-handling systems? Here’s one simple strategy that I advocate for on every project I can – direct drive fans.  Why?  No belt losses (energy) and less maintenance (money).

As a building commissioning provider, I’ve only seen one project team take me up on that suggestion.  One.  Engineers most often note that the equipment simply isn’t available with direct drive fans.  This may be true for an “off the shelf” piece of equipment, but nearly every air handler I see is custom made, to one extent or another.  Tell your rep you want a direct drive fan and I bet he or she will find one for you.

Why forgo belts? 

First, belts waste energy.  Typical V-belt losses vary between 4 and 8% depending on motor size and speed.  AMCA 203-90 addresses this.  AAON® cited the AMCA 203 data in The Cost of Belt Drives. (pdf)  Even 6% of the energy to run a 10,000 CFM air handler is roughly 2/3 HP.  Doesn’t sound like much but combined over a handful of units and applied over their life expectancy and it adds up.  Another consideration is that an under-tightened belt will slip, further increasing the belt loss, by as much as an additional 4-6%.

Second, belts cost money to buy and maintain.  Here’s a photo of a recent project I was involved with. Roughly 30 different belts!  Someone has to inventory all those belts and maintain all those systems – time and money that could be spent elsewhere or saved. AAON shows a $20,000 maintenance cost over the 17-year life of a 3-HP rooftop unit.  Even if you take their economics with a grain of salt, you can’t argue that’s a lot of money – FOR ONE UNIT!

What’s the solution? 

Direct drive fans are the solution, but you already knew I was going to say that.  What if your fan selection isn’t a standard motor speed?  No problem – put a variable frequency drive (VFD) on it and set the max speed you need in the drive.  There’s no problem running a motor at, say, 70 Hz either as long as the motor is sized for the expected amperage.  Most systems today utilize variable speed control anyway so the drive is already there!  Got a fan selection that’s 1000 RPM?  Use a 1200 RPM motor with a drive set to a max output of 50Hz.  2000 RPM?  1800 RPM motor with a drive set to a max output of 67Hz etc.

Want an added incentive?  The variable frequency drive boosts the utility side power factor to near unity.  Larger customers get charged for low power factors (PF).  The charges and thresholds differ by utility, but they’re there.  How?  Basically, the motor PF is separated from the utility via the drive’s DC bus, but that’s another topic.

There are always other things to consider too.  Drives with bypasses make the under speeding of a motor tricky.  In bypass mode you could easily trip the over-current protection.  For over-sped motors you don’t get the design CFM in bypass mode, but the bypass should only be temporary.  Drives with bypasses are not that common, except in critical applications, so I consider them an exception to the rule.

In short, with a little foresight, you can apply direct drive fans in the majority of applications with little or no added cost and the benefit of increased efficiency and reduced maintenance costs.  Give it a shot!

Related articles

• Variable Frequency Drive (Canada Natural Resources)
• Servicing V-Belts and Drive Pulleys (jcijcp.wordpress.com)

We often hear a question that goes something like this from building owners: “Why do I need an independent design review? I hire the best architects and engineers.” It’s a reasonable question — asked so often in my opinion because those of us in the architecture, engineering and construction industries have done such a poor job answering.

First, A Definition

Although design review is a term used in many fields, it consistently includes two elements — independent review of the design against the project’s requirements. A definition that works across fields looks something like this: “A design review is a milestone within a product or building development process whereby a design is evaluated against its requirements in order to verify the outcomes of previous activities and identify issues before committing to, –and if need be re-prioritizing– further work. The ultimate design review, if successful, therefore triggers the product or building launch. By definition, a review must include persons who are external to the design team.”

More than LEED Design Review

In the building construction industry, design review emerged as part of the commissioning process in the late 1990’s. Both the California Commissioning Collaborative and ASHRAE are advocates of design review. It is widely recognized that design review earns credit for Enhanced Commissioning in the LEED green building certification process, but what are the advantages of a design review if yours is not a LEED project? I see four key benefits to including a design review in your commissioning process.

1. One Firm’s Practices or Proven Best Practices?

An independent design review differs from one engineering firm’s internal checking. An independent set of eyes can look beyond the design firm’s internal design practices and office culture by presenting a different method to consider, based on successful implementation of previous projects from designs by multiple firms.

The architecture and engineer (AE) community (just like the construction industry) is slow to change: misapplications from one generation of engineer or project seem to continue to the next. In recent decades, the design fee as a percentage of construction costs has decreased significantly. Engineers now have far less time in their fees for time on job site. And time in the field, especially during startup and operational testing, is where one learns very quickly what works very well and what can be done better during the next design project.

2. Reduced Construction Costs

A design review can add value to the design by reducing construction costs. Here’s an example: Consider the design of a new 10 HP pump, initially designed as a constant speed/constant flow pump. The design engineer assessment concluded: “It’s too small and not worth the cost of adding variable frequency drives (VFD)”. A third party design review would point out it is less expensive to install a VFD than a traditional motor starter. The reviewer would note annual pump operating costs would be cut 62%, avoiding 31,000 kWh a year, while dropping operating costs by $3,700. per year. And that’s not just one year; it’s every year going forward, for compounded savings.

This is true added value by reducing construction costs while concurrently reducing the owner’s overhead for the next 20 years.

Sometimes a reviewer may observe a design may not be in compliance with say, a ventilation code. While the remedy will likely increase construction costs, and possibly operating costs, the high level of indoor environmental air quality can be assured. And that may have a positive impact on productivity. This is a choice the building owner wants to at least be aware of.

3. Varied Perspectives

We each have our unique, individual blinds spots. An independent third party can point these out to a design team. It is a desire to add this varied perspective that drives the use of design review in the new product process in most industries, the software development system around the world, and in the building industry. A third party with significant commissioning and operational experience adds the perspective of installation and operations from multiple projects designed by multiple firms. A third party can suggest successful solutions from other previous projects. This institutional knowledge is shared with the entire team and adds value to the project.

4. Communication Means Fewer Errors

The least acknowledged benefit of a third party design review is fostering communication between designers, owners, and builders. Better communication reduces errors and omissions. When you think about it, aren’t most problems fundamentally due to a lack of communication?

Related articles

WBDG, National Institute of Building Sciences

ASHRAE Guideline 0, The Commissioning Process