Tag Archives: energy efficiency

A Closer Look at Energy Conservation Measures – Window Replacement

As promised, here are more highlights from a recent energy audit and retro-commissioning assessment project. The energy conservation measure (ECM) I’d like to highlight this time is upgrading a facility’s windows.

The majority of the existing windows in our case study are single pane with wood frames in fair to poor condition. With window replacement there is an opportunity for thermal efficiency improvement with the installation of windows with better insulating properties. Typically, energy savings from window replacement are a result of reduced infiltration from gaps and cracks around window frames and glazing and from reduced heat transfer during the heating and cooling season. For a conservative savings estimate associated with this measure, the calculations below are only based on improvements to the windows’ thermal properties.

Overall, we calculated a savings of approximately $5,857/year (based on improvements to the windows’ thermal properties) with a simple payback of nearly 200 years! What can be recommended with these stats? Window replacement was considered, but the economic payback did not justify implementation as an ECM. Therefore, we suggest that when window replacement is required, high performance windows should be used. Replacement windows should have insulated frames (with thermal breaks), two or more layers of glazing with an inert gas “air” gap between and solar heat gain coefficient appropriate for the window orientation and desired level of solar heat gain.

Although not all ECMs end with a recommendation for implementation, this facility can now plan appropriately for the future. When putting together their budgetary needs, they can now reference this study to plan more accurately and most efficiently.

What are some lessons learned from your building energy studies? Have you recently replaced your windows? How did you choose the best fit? Share your thoughts and questions in the comments below.

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Top Tips and Pitfalls of Implementing Energy Conservation Measures (ECMs)

Now that we have developed an energy audit and/or retro-commissioning report, it is time to implement some of our findings. Which energy conservation measure (ECM) to implement has a lot to do with your facility’s priorities and needs. Typically, the ECM that makes the most sense to implement is the one with the greatest return on investment. When investigating implementation, one must keep in mind that some ECMs may be linked. For example, if an ECM involves upgrading your current BMS system, it may initially seem unappealing because of the long return on investment. However, you may want to consider this ECM if it is tied to another ECM, such as adding a reset control or an air side economizer. Both of these are better served if the BMS is upgraded first.

An example of a pitfall, however, includes upgrading current motors to energy efficient motors. I am always a proponent of saving energy, but this particular investment may not make sense based on your facility’s current utility rate and the run time of your motors. A real-life example of this is in a primary school we recently worked. It was identified that the existing HVAC motors were not premium efficiency motors. However, after investigation and pricing, the payback was calculated to be 180 years! This ECM was therefore not recommended, however, if the motors should fail and require replacement, it was recommended to replace them with premium efficiency motors. The most logical thing to do is to work on your low cost/no cost measures. This includes items such as schedules, thermostat recalibrations, sensor recalibrations, etc.

The key to implementing ECMs is to have a plan and document what your intentions are with your report. Identify which measures you are going to implement going forward, who is going to do the work and how you are going to check that the implementation measures were installed correctly and are working. Once we have a plan, it is crucial to share it with ownership so they understand what you are doing with the report and their recommendations

Whether you are planning to use in-house labor or contract labor, a clear scope of work is imperative to making your implementations successful. Clearly define the level of expectations, desired results and most importantly who plans to be in charge of and manage the implementation program.

Scheduling your work to minimize disruptions to your tenants and end users is also important. Having regular job check-in meetings are vital to keeping the project on track with either formal or tool box sessions.

Over the next couple of months, I will be discussing details regarding a dozen or so commonly found ECMs and the pros and cons of implementing them. Stay tuned! As always, if you have any questions, leave a comment below.

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Existing Building Energy Consumption: Current Situations, Trends, Legislature and Solutions (Series Post #8: Real World Application, Case Study)

After all this talk about how great energy audits and retro-commissioning is, let’s take a look at a case study which shows the power of these tools in action. We worked on a historic 555,000 sf museum, originally built in 1897. After an energy audit and retro-commissioning study, the facility will save approximately $520,000 in annual energy savings with a simple payback of a little over 2 years.

Major energy conservation measures (ECMs) that were found in the energy auditing process include: retrofitting gallery light fixtures from incandescent and halogen to CFL/LED lamps, upgrading the old pneumatic controls to direct digital controls (DDC) for AHUs and implementing several control strategy upgrades, such as gallery VFD speed optimization, economizer controls and demand control ventilation.

Through the retro-commissioning process, HEA determined several key retro-commissioning measures (RCMs). A selection of issues found include: non-functioning hand-off-auto switches, inactive BMS points, improperly wired supply and return fans, leaking cooling and heating coils, faulty smoke detectors and AHU steam valve leaks. Testing, adjusting and balancing (TAB) for all air and water systems, setting up an AHU BMS scheduling program and the partial free cooling in the chilled water system were key low to no cost RCMs that were identified.

Major operations and maintenance measures (OMMs) include a steam trap survey, boiler tune-up and cleaning and AHU temperature and humidity sensor calibration.

These results prove that proper energy audits and retro-commissioning services can help significantly reduce energy usage in existing buildings. In some cases, repairing or replacing equipment may not be the best fiscal decision based on ROI. The key is to implement the ECMs that make sense for your facility; both operationally and fiscally. Make sure your provider has the proper understanding to prioritize and recommend the best path for the future of your facility.

Thank you for reading my series about existing building energy consumption. Please feel free to ask me any questions and/or leave a comment below.

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Existing Building Energy Consumption: Current Situation, Trends, Legislature and Solutions (Post #1: Introduction)

Existing Building Energy Consumption: Current Situations, Trends, Legislature and Solutions (Series Post #1: Introduction)

Our nation’s current energy appetite needs to be curbed. And while there are many solutions out there, I wanted to share my thoughts specifically with energy use and efficiency in buildings. My reason for choosing this topic is twofold: 1) Buildings account for a large portion of the US energy consumption (see more details below) and 2) Throughout my 20 years of experience with building commissioning (new construction and existing building), I have witnessed how commissioning and energy studies contribute to not only energy savings, but lower maintenance costs, increased occupant satisfaction and improved building documentation.

Why look to buildings?
The U.S. buildings sector accounted for 7% of global energy consumption in 2010. We must re-evaluate our fossil fuel consumption patterns which have been directly linked to climate change in order to mitigate the adversities we are facing. Buildings accounted for 41% of primary energy consumption in the U.S.; that is 44% more than the transportation sector and 36% more than the industrial sector. Buildings are identified as being responsible for the largest portion of our country’s carbon dioxide emissions; therefore, it seems the best way to combat climate change and create a sustainable future is to demand a higher standard from our buildings.

The federal government estimated that we can save $40 billion dollars annually by reducing energy use in commercial buildings by 20% by 2020. With people spending 90% of their lives inside buildings, we must work to provide buildings that are operating at ultimate performance. We need leadership and coordination to implement legislation. We need education to allow people to make the best choices. We need research and development to cultivate the technology and practices to ensure sustainable energy solutions. My future posts to this blog series will look at current trends in energy efficient buildings such as energy audits and the impact they have on building systems. The posts will explore the different organizations and principles set forth for better building systems such as ASHRAE. I will then tie in my personal experience and lessons learned as an active commissioning professional in order to explain and exemplify the importance of commissioning, retro-commissioning and energy audits.

I will be publishing a new post every other Thursday. Any topics and/or questions you would like me to address? Leave me a comment and I’ll make sure to reply. I hope this is the beginning of a great discussion.

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The Benefits of Demand Response Programs

What have we learned from the latest heat wave in the Northeast? As temperatures rose into the triple digit mark and demand for electricity moved higher, what are we doing to curtail usage? Few commercial buildings have subscribed to a demand response program and the residential market is still in the dark.

Demand response programs allow for buildings to be part of the smart grid and curtail their energy usage during peak demand to reduce the load on the grid. Customers can qualify for incentives from their utility companies by participating in a demand response program.

In the event of high demand on the electrical grid (like 100+ degree weather days), the utility company would call certain customers to reduce load in their building to help curtail the large demand that is on the electrical distribution system. It is a great way to try to reduce the burden of electrical generation through the utilities area. It allows plants that produce power efficiently to stay on longer and reduce the amount of power generation that is old, inefficient, and costly to the environment.

Some utilities still don’t have such a program which is counterintuitive to the larger picture of reducing costs, providing customers with costs savings options, and helping the environment.

We all need to be part of a demand response program. Why not get paid to help the environment?

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Keep Your Money from Going Out the Window

We’ve all been told as children – “Turn off the lights when you’re not in the room” and “Don’t leave the water running when you’re brushing your teeth.” Now, there’s so much more we can do to conserve energy and resources in our homes and businesses. There is heightened awareness that our “small and insignificant” actions collectively have great impact on the environment and personal/corporate budgets.

To know how much energy we spend (or waste); we need to assess the situation and come up with a baseline. Just like we all go to the doctor every year and take our cars in for inspection, our homes and offices need the same check-ups. Hence, the energy audit. In short, an energy audit is a way to determine the energy consumption of a building. These audits can help individuals see where money and energy are going out the window (sometimes literally). For one of our clients, we found they were using 2.28 times the average electricity and 1.65 times the natural gas for buildings of their type. We identified 15 Energy Conservation Measures totaling a possible savings of $615,000 and approximately 30% reduction in energy use. These audits help identify troublespots in the property and methods for improving the building’s performance. Alterations can be as simple as changing light bulbs or as complex as overhauling the heating and cooling systems.

Being efficient is more than saving money; it’s about preserving our natural resources and minimizing our impact on the environment. Many elite corporations are leading the charge by greening their business practices and supply chains. They’re educating their employees on how to make eco-friendly decisions. Further, they’re investing in their buildings via retrofits and even building according to green standards such as LEED.

Building green is booming because this generation demands socially responsible corporations and healthful work environments. Unfortunately, some still cite heavy upfront costs as an obstacle to building green – materials are more expensive, the LEED process comes with additional costs and it just takes more planning and innovation.

Great ideas, innovation and progress come from challenging situations fraught with limited resources. In the case of building green, the financial aspect is favorable to the cause. A USGBC-funded study of LEED buildings in NYC found that there was no significant price differential for construction costs between LEED and traditional buildings. According to the analysis, the average construction cost for a LEED high-rise residential building was $440/sf and $436/sf for non-LEED. I think an extra $4/sf investment is worth it, especially since the returns include better air quality, lowered utility bills, increased productivity and less pollution-spewing buildings.

If we’re going to tackle the looming issue of global warming, we need to take one conscientious step at a time – whether it’s turning off the light, doing an energy audit, investing in a retrofit or starting from scratch and building green.

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Green Today, Gone Tomorrow

The USGBC recently launched its new program (v.03) that includes recertification of buildings each year. In addition, the LEED-EB program has a recertification component that must be completed annually. There has been an uproar in the green building industry arguing that a building is not just about energy consumption, but also the types of construction material used, site selection and occupant comfort.

I agree that material selection and indoor environmental quality is just as important to getting a building certified as being energy efficient. However, let’s not kid ourselves in thinking that a building that fails to remain a good steward of the environment should continue to hold the privilege of being called a green building. A building that drastically consumes more energy than when it was originally certified has issues that require investigation. Sadly, the green has wilted away and has turned brown.

Let’s look back at why we call it sustainable building. Sustainability focuses on constructing a building that efficiently consumes energy, water and other resources with minimum impact to occupants and the environment. How a building consumes energy and expunges waste contributes to its carbon footprint. Current technology does not allow for buildings to operate fully on clean energy; therefore, existing buildings continue to leave huge footprints causing irreversible damage to the environment. It should be every building’s goal to keep its footprint to a minimum by performing proper maintenance on its systems and constantly monitoring its energy patterns to identify opportunities for conservation.

Optimal building sites, sustainable building materials and healthy indoor air quality are important characteristics for green buildings and should be incorporated into the certification process. These factors should be considered at the baseline and are unlikely to change significantly overtime. However with daily use, a building’s systems and equipment may come out of sync, become old, outdated and inefficient, resulting in greater consumption of energy and increased waste. Without constant vigilance to determine how much energy these buildings consume on a daily basis, we cannot guarantee that these buildings are living up to their green labels. Without these requirements for energy monitoring, I agree with critics who favor decertification of buildings who fail to meet LEED standards following their initial certification.

The LEED certification process says a lot about how building owners view energy. Following a comprehensive design, an energy model should be performed to predict how the building will function. But it shouldn’t stop there. I’ve seen companies brag about their supposed “LEED-certified” buildings, screw the plaque onto their pristine walls before commissioning is completed and actual building performance is validated. What message is the USGBC sending when they give certifications out before performance is verified? There is no value to the plaque if a building doesn’t measure up to LEED standards from the beginning or throughout its lifecycle.

I have requested the USGBC to modify its program during revisions in LEED-NC 2.2 and my suggestions fell on deaf ears. If the USGBC will not change its policy on certifying new buildings prior to validating its energy consumption, then I say grab the screwdriver and uninstall the plaque after the first year if the building doesn’t meet Energy Star requirements. This may sound harsh, but we must have integrity and make sure our buildings perform as we say they do.

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