Ed Ritchie 2015-07-22 17:34:37
The marketplace for products and services that address building energy efficiency is growing rapidly, and that means economic benefits for businesses and institutions. From the building’s entrance, to the roof and the space inside, there’s a wide spectrum of technologies available. We could talk about HVAC, lighting, water efficiency, water heating, building envelope, energy production, and more. But today, let’s narrow it down to the building envelope, and some of the key improvements that a business can make—easily, and without busting the budget. Considering all of the important categories listed above, focus on the building envelope might come as a surprise; however, if you’re operating your business or institution in a structure that wastes energy, there’s a direct correlation to the energy consuming systems within that structure. And the impact can be surprising, according to Ulrike Passe, associate professor of architecture, and director of Iowa State’s Center for Building Energy Research. Passe teaches architectural design and environmental technologies, and researches areas of integrated design and building energy performance evaluation, and air flow and energy. She is the co-author of a new book, Designing Spaces for Natural Ventilation: An Architect’s Guide. “The envelope has an important role, and there can be an impact of 40 to 50%, if not more,” says Passe. “One point of energy waste in a building envelope happens through infiltration. Ventilation is the intended use of the air, whereas infiltration is unwanted air. Ventilation is conditioning deliberately, but you can also exchange the energy of incoming and exhaust air with technology. But when you have leaks in the building, that doesn’t happen.” A building’s design and construction can also waste energy. Structural materials such as the timber frame or steel have to be insulated properly or they act as a thermal bridge that conducts heat from inside the building to the environment. You can reduce that loss by insulating the exterior of the building. For hot climates, the insulation should be on the inside, to keep the cool in and the heat out. Fenestration Next on Passe’s list is the building’s fenestration components: doors, windows, and skylights. “You need to seal every window and opening because that’s a critical factor for energy efficiency these days,” advises Passe. “The better the windows and doors, the more holistic the performance of the envelope.” In fact, the performance of energy-efficient windows can be significant, as in the example of 625 North Michigan Avenue, a 25-story office tower located in downtown Chicago. It was constructed in 1970 and has approximately 350,000 square feet of conditioned space. Even though the building had previously been retro-commissioned to perform to higher energy efficiency standards, an interior curtain wall retrofit system increased energy savings by 16%. The windows, supplied by Thermolite, headquartered in South Bend, IN, were comprised of the company’s RetroWAL interior curtain wall retrofit system, and included three models: ¼-inch laminated glass with low-e hard coating, 1-inch insulated glazing unit with low-e soft coating, and ¼ inch laminated glass with low-e hard coating, plus 1-inch blinds in the air cavity. The fenestration industry has made great progress in energy efficiency, according to Tom Herron director, communications and marketing, National Fenestration Rating Council, Greenbelt, MD. “One of things that makes this industry so exciting is the smart technology,” says Herron. “For example, we’re seeing window shades, sensors, and lighting controls. Eventually, we’ll have smart windows that adjust to your preferences or energy requirements. It’s important because people don’t realize that there is a tug-of-war between the sun’s heat and the glass, so the HVAC system has to work harder.” One of the main goals of the NFRC is to help building designers and facility managers in meeting the growing list of regulations. “There are fenestration energy codes for commercial and residential buildings,” says Herron. “But the main thing to keep in mind is the overall performance of the glass, and the NFRC’s ratings provide the whole range of product performance. They take everything into account, including the framing, glazing, and spacers, and we rate doors and skylights. So the NFRC label on a product is your assurance that it’s going to perform the way it’s advertised.” When it’s time to consider a building’s energy load, performance specifications are important for architects, designers, and engineers who need to know the ratings of a building’s fenestration components. Says Passe, “When an engineer sizes an air-conditioning system they include the building envelope in their calculations. The envelope is the starting point for all system decisions. For example, if you have solar gain in summer, it’s detrimental to your cooling load. So a wall with unshaded glass exposed to sunlight would require you to turn up the air conditioning, and the same with black roofs. A black roof heats up more than a white roof, and the heat going through the roof is determined by the surface temperature of the roof. So the material for the roof is critical, and that’s why in California we see so many white roofs.” Roofs A white roof is just one of many variables in roofing, according to Ryan Shinn, manager, Western Group Marketing, CentiMark Corporation, based out of Carrollton, TX. “You have to look at the thickness of the installation on the roofing system, and the type of lighting that will affect the efficiency of the roof. Also, the ambient temperature and climate. Then, the type of building can radically affect the direction you want to go with your design and materials.” As research continues for longer lasting materials, recent breakthroughs have led to new plasticizers that are used in Poly Vinyl Chloride (PVC) roofing, and these allow PVC to resist UV radiation. Shinn says, “PVC roofing is big in chemical manufacturing industries and certain food processing because it resists chemical degradation.” PVC makes for a thermoplastic roof system that is white, and a highly reflective membrane. These roofs provide strong weathering characteristics, along with puncture and tear resistance. Sheets are welded together using hot air, and these types of roof systems are lightweight, and well suited for second-generation (roof-over) applications. “We also have better inspection techniques, such as infrared tools, to detect hotspots and areas where water is entering the building through the roof,” adds Shinn. “You want your roof system to be as energy neutral as possible to prevent uneven heating or cooling.” Roofing materials are also going green, literally. For example, the Findlay Teller Apartments in Bronx, NY, recently installed a living green roof manufactured by Xero Flor America (XFA) based in Durham, NC. The 9,825-square-foot Xero Flor green roof system includes lightweight, pre-vegetated mats that were delivered with well-developed, mature plants. The Xero Flor vegetated mats were rolled out like sod for easy installation. All told, XFA has supplied nearly 90 green roof installations in the New York City area covering more than 600,000 square feet. Green roofs have gained in popularity in progressive cities like New York, according to Clayton Rugh, XFA Manager and Technical Director. “The green building industry has grown dramatically over the past 10 years through increased technical awareness by the design and construction community,” says Rugh. “Consequently, New York, and many major US cities—such as Washington DC, Philadelphia, Seattle, Portland, and Chicago—have become thriving green roof markets.” Driving green roof adoption nationwide are the many sustainable environmental and economic benefits. “LEED certification is one of the strongest incentives,” says Rugh. “Green roofs provide or contribute as many as 24 LEED points through thermal protection, stormwater management, water reuse opportunities, and other benefits.” Additional LEED credits can be obtained from use of native flora, local sourcing, and used of recycled and renewable content. Rugh notes “Xero Flor has a strong LEED position because our production fields and component suppliers are located near major metropolitan areas, so offer local sourcing for most American projects. In addition, Xero Flor America green roof materials are 100% US manufactured with a very high percentage of recycled content in our products.” Aside from sustainably sourced products, how do green roofs affect building energy performance? “Green roof provide thermal protection through three different processes,” says Rugh. “First, it’s a lighter colored surface, so it remains cooler than a dark-colored membrane. Also, a vegetative roof dissipates heat load by evaporating water from leaves and stems. These processes combine to enhance building air-conditioning efficiency by reduced thermal loading through the roof structure. Moreover, the green roof assembly acts as a protective covering to prolong the life of a roofing membrane that would otherwise be exposed to solar UV radiation and extreme heat-cold cycles.” Audits We’ve talked about some options for improving a building’s envelope, but the gains in energy efficiency need to be measured, and that involves an energy audit. As with the other technologies we’ve discussed, the practice of energy auditing has advanced in recent years. For example, auditors now have access to cloud-based systems, such as those offered by EMAT (Efficient Mobile Auditing Technologies), a Frederick, MD-based company with a tablet-to-cloud technology that cuts the time and cost of conducting energy audits by 50% or more. “This product is meant to give you the capability to do everything that a Level II ASHRAE audit would include,” says EMAT’s CEO, Ken Malnar. “That includes data collection, calculation, and report generation. The information is segmented for different capabilities. If you just wanted to use it for the data collection side to organize data and send it back to your office efficiently, you can use it in that capacity. But if you want to do calculations and generate your own reports, you can do that, and if you want to do it from start to finish, you have that capability also.” The calculation function is very critical because it can identify energy conservation measures. “The point of doing onsite audits is to either identify projects or meet requirements,” says Malnar. “EMAT helps identify the projects and puts out a report that meets the requirements for government agencies and regulators.” Many cities and states are imposing strict regulations for energy usage reporting. For example, in New York City, Local Law 87 requires all buildings over 50,000 square feet to perform retro-commissioning of systems, and to submit an energy efficiency report based on a building audit performed by a qualified energy auditor. In San Francisco, the city’s Environment Code Chapter 20 Existing Commercial Buildings Energy Performance Ordinance requires an energy audit every five years. Looking globally, the challenge of climate change has influenced many countries to implement similar measures to reduce energy consumption and greenhouse gas (GHG) emissions. Since residential and commercial buildings account for 35 to 40% of total final energy consumption, regulations are becoming commonplace, and the industry is growing to provide solutions. According to Navigant Research, global revenue for energy efficiency commercial building retrofits will grow from $68.2 billion in 2014, to $127.5 billion in 2023. “Today, most facility owners and property managers have some sort of energy manager or facility staff onsite,” says Malnar. “And though the EMAT system was designed for auditors, it’s not limited to those professionals. An in-house person can use it, but they should have some energy management understanding and background to conduct these type of audits for their facilities. The targeted audience is Energy Service Contractors and energy companies that are out there performing audits, but we think it’s very applicable to the property owner and management industry as well.” Additionally, EMAT’s remote capabilities are attractive for energy auditing companies that want to utilize their tools to modify their auditing procedures. “They can send newer staff on location with the energy auditing application, and that means lower costs out in the field,” says Malnar. “That allows them to keep their certified energy managers back in the office, ready to take the data and generate the reports without having to wait for the auditor to return from the field and translate their pen and pad notes.” Audit reports have been time consuming tasks for energy managers, taking weeks—and more in many cases. But that has changed, says Malnar. “EMAT comes with some standard templates, and after you’ve done the data collection, the system scans thousands of data points to discover that data point you’ve entered onsite, and it automatically generates a report solution,” he says. “So, your audit starts with a report that’s about 70 to 80% complete just based on the data you collected. At that point, you’re ready to start analyzing the data and put the finishing touches on a report. We allow our customers to work with us in implementing a custom report for them and use their logo. They can modify the title page and add images. We allow them to use our thousands of data points that we have collected to build and customize their report so at the end of the day they have their own template, populated with the same data points they are collecting onsite.” One of the unique features of EMAT is that it addresses water savings. “We have found that many companies overlook the potential value in simple water saving measures, such as adding low flow aerators to sinks,” says Malnar. “These water saving tools and energy conservation measures will save on heating the water and the water itself so you get a double value. Another trend we’re seeing is that LED lights are dropping in price. So now is the time to take that leap forward and change from T8 fluorescents to LEDs.” Visibility and Commissioning Once you’ve done an energy audit, you’ll benefit from commissioning your building, and commissioning through visibility is the ideal method, according to Ken Buda, Product Manager Budderfly LLC, out of Shelton, CT. “You can't manage what you can't see,” says Buda. “The Budderfly system shows you exactly when and where your energy is used. And you can break down your usage by type of device, location, or time.” The Budderfly system uses a micro-metering approach of measurement that installs sensors down at the device level, to help control plug loads and lighting. The adapters are simple plug-and-play replacements for existing outlets, switches, thermostats, and more. They measure energy consumption at the device and provide a granular view of your energy spend, as well as control of individual devices, so devices can be scheduled to turn off automatically. Moreover, the automated controls aren’t limited to time scheduling. They can be based on ambient light, occupancy, consumption, or a utility’s demand response program. Adler Realty Investments, recently used Budderfly’s energy management technology to solve a mystery at a property in Woodland Hills, CA. The property is part of a multi-building office complex, and had one unit in the office park that registered unusually high electricity consumption compared to its peer buildings. To isolate the source of excessive energy consumption, Budderfly installed intelligent light switches, advanced power strips to monitor and control plug loads at the workstation level, temperature sensors, and electrical panel-level monitoring devices. “The owners thought that the tenant’s information technology department was the cause of the unusual consumption,” recalls Buda. “But the real-time data gathered by the system revealed that HVAC efficiency and control strategies were driving excessive consumption. This coupled with the tenant’s extended operating schedule caused higher than normal usage.” Once the mystery was solved, the tenant had granular data on their energy consumption that allowed them to address the HVAC system and other devices to help with lowering their energy bill. Ultimately, lowering a building’s energy bill is the common thread that ties together the building envelope, energy auditing, and re-commissioning plus system automation. We’ve seen how fenestration systems, such as windows and roofs, can impact the envelope, and how energy audits can empower building managers. Finally, there are powerful monitoring systems to manage energy usage at the device level. With these energy-efficient technologies within easy grasp, isn’t it time to take a look at the savings and benefits they offer? Ed Ritchie specializes in energy, transportation, and communication technologies.
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