Technologies for Energy Efficiency

Professionals have many choices for the delivery of energy-efficient solutions to their clients, from harnessing the sun for solar hot water, to providing options for indoor air delivery and using energy-efficient windows.

Celeste Allen Novak AIA, LEED AP

THE CALL FOR ENERGY EFFICIENCY

In June, 2009, President Obama and U.S. Energy Secretary, Steven Chu, announced a major initiative towards promoting energy efficiency. "One of the fastest, easiest, and cheapest ways to make our economy stronger and cleaner is to make our economy more energy efficient," said President Obama. "That's why we made energy efficiency investments a focal point of the Recovery Act. And that's why today's announcements are so important. By bringing more energy-efficient technologies to American homes and businesses, we won't just significantly reduce our energy demand; we'll put more money back in the pockets of hardworking Americans."¹

For professionals, this means new incentives for increasing the energy efficiency of buildings. Manufacturers are responding to this call with new technologies and new corporate commitments. "Advancing energy efficiency as an important first step toward sustainability makes sense no matter how you approach it. Whether it is about home efficiency, vehicle efficiency or large-scale building efficiency, we all have a role to play. The renewed focus on personal and corporate financial responsibility furthers the attractiveness of the myriad solutions available today to consumers and businesses, it adds up financially as well. It's about more than carbon emissions it's also about the bottom line," commented Scott Alwine, LEED AP, and Marketing Manager at Tate Access Floors.

Hot water from the sun adds to the environmental serenity of this lake house view. Photo courtesy of Amador Solar

The Bank of America at One Bryant Park in New York City is designed to be the world's most sustainable building. This project prioritizes fresh air and personal temperature controls through the incorporation of a raised floor air distribution system on every floor. Photo courtesy of Cook + Fox Architects

Professionals have numerous choices for assembling and integrating both new and old technologies to provide energy efficiency. Some of these choices are based on principles of human comfort, as well as an analysis of return on investment. This article will discuss a few of the many ways to effectively use nature to provide individual comfort as well as energy efficiency. The understanding of the biometrics and physics of air movement from ceiling fans, to raised floors with underfloor air distribution are ways to combine comfort with personal control of your environment.

The intent of One Bryant Park was to become the most sustainable office building in the country. Cook + Fox Architects researched numerous building systems and materials, looking at both energy savings and health and productivity design strategies. "Choosing an underfloor air delivery system," says architect Serge Appel, AIA, LEED AP, Associate Partner at Cook + Fox Architects, "increased the perceived value of the space. More importantly, when you allow individuals to have control over their own environment, you increase their happiness."

In addition, the components of energy-efficient windows will be discussed along with the newest EPA regulations for thermal efficiency. Designers will also learn how solar hot water can be installed to reduce both home and commercial hot water heating bills. "Solar hot water is the most practical renewable method to heat water for domestic or commercial use as it's generally three to four times less expensive than a solar Photovoltaic (PV) system of similar energy output. And with approximately 100 million inefficient water heaters installed in the U.S., there's a great potential for improving our energy supply and our environment," said Ole Pilgaard, President of Heliodyne.

AESTHETIC CHOICES

Leading the way in energy efficiency doesn't have to mean a sacrifice in design vocabulary. Artists and industrial designers are all taking up the challenge of making new forms for sustainable design practices. Design entrepreneur, Ron Rezek, designed the world's first contemporary ceiling fan design. He states that ceiling fans are "designed to be functional and energy efficient. This is part of being contemporary and pushing the edge. Energy efficiency is the wave of the future."²

Subtractive simple forms update this energy-efficient ceiling fan to new design sophistication. Photo courtesy of The Modern Fan Co.

 

Window manufacturers are developing new fiberglass profiles that can be painted in numerous colors to allow architects to select from a wider color palette than ever before. "These windows are impervious to water, cold, insects, salt air, and ultraviolet rays. The result is energy-efficient fiberglass windows that maintain their beauty in every season, in any climate," according to Maureen Faccia, Director of Fiberglass Product Management from Milgard Windows & Doors.

Professionals are adding many different technologies into their toolkits. Responding to energy demand requires knowledge of basic human comfort as well as an understanding of the number crunching necessary for saving money.

The view of the water is framed by energy-efficient fiberglass windows. Photo courtesy of Milgard Windows & Doors.

SOLAR HOT WATER

The U.S. Department of Energy (DOE) estimates that over one million solar hot water systems have been installed throughout the United States. With respect to other hot water systems this means less than one percent of all hot water comes from the sun. Ole Pilgaard conservatively predicts that this number will increase to 5 percent or more in the next 20 years. In fact, beginning in 2010, sunny states like Hawaii are beginning to mandate solar hot water heating in all new homes. The state's Governor, Linda Lingle, signed this legislation that will prohibit issuing building permits for single-family homes that do not have solar water heaters, with exceptions for homes in forested areas.³ One motivation for this legislation is energy savings; the other is to reduce Hawaii's reliance on imported fossil fuels. "It's abundantly clear that we need to take some serious action to protect Hawaii because we're so dependent on oil," said State Sen. Gary Hooser, vice chairman of the Energy and Environment Committee, adding, "I'm very pleased the governor is recognizing the importance of this bill and the huge public benefits that come out of it."⁴

Solar hot water heating can be installed for both residential and commercial applications saving money by offsetting the energy used to heat water. "Water heating currently represents up to 17 percent of national residential energy consumption, making it the third largest energy user in homes, behind heating and cooling, and kitchen appliances."⁵ The solar panel industry, now over thirty years old, has developed new "plug and play" systems that make solar hot water systems easy to install in as little as one or two days.

Components of a solar hot water heating system

A solar hot water heating system usually has three main components:

A collector - filled with either water or in cold climates, a glycol solution A heat transfer assembly which consists of a controller, pumps, heat exchanger, and various gauges and valves A solar storage tank that holds the solar heated water plumbed to a traditional hot water tank or tankless hot water system, which are used as a backup heating source

Some solar manufacturers offer single-tank solar hot water solutions for homes with limited space. In a single-tank system, an electric water heater is generally used to provide both solar storage and backup heating. Because the solar system will pull cold water from the bottom of the tank, the bottom electric element must be removed. The top electric element will only self-activate and heat the water when the solar system cannot. A single-tank system can also be achieved with the use of a tankless, on-demand water heater to provide backup heating. Most manufacturers will give a ten-year guarantee for their collectors and five years for heat transfer components. The life expectancy of a solar hot water system is well over 20 years.

Twenty-eight solar collectors line the roof of Fenway Park. Photo courtesy of Heliodyne

Ease of installation

Early collector technology of the 1970's included the manufacture of the panels and parts as separate entities. An early solar pioneer writes in 1977, in the Whole Earth Catalog: "Our solar heater was a square box affair and it had four tanks in it and it was covered by glass. It faced southwest, of course, just the direction the house was. It was our main supply of hot water. The pipes came down through the house from the heater, one went to the bathroom, and one went to the kitchen. There was no excess of plumbing."⁶ Today, solar hot water heating systems can be installed by most plumbers. These solar panels are specified in one pre-packaged "plug and play" unit. The collectors, heat exchangers, controllers, and storage tanks are provided with standard NPT plumbing fittings to make connections to home plumbing systems an easy fit. The installation of a typical hot water system takes approximately two days.

Day 1 - the installer checks the orientation of the roof for placement. The ideal orientation is to have the panel face true south or be within 15 degrees. The roof slope should range between 20 and 45 degrees, however, some panels can be installed in slopes from 10 or15 degrees. In snowy areas, the recommended roof slope is at least 30 degrees and a 10 degree slope is a minimum for rain to wash leaves and dust from the collector surface. The solar aspect is also reviewed to see how many hours of the day the roof receives direct sunlight without being shaded by adjacent trees or buildings.

A solar collector is sized not by the square footage of the home, but by the number of people living in the home. Installers estimate that a typical homeowner will use up to 20 gallons of hot water per day; for a family of four the storage tank will be sized for 80 gallons.

Collector placement is determined by solar aspect as well as relationship to existing or new plumbing fixtures. A solar storage tank will be placed next to an existing hot water tank in the garage, basement or in a centralized location in the home from which hot water is distributed. The shortest piping run is the least expensive and plumbing lines can be up to 100 feet without resizing pipe diameters.

Day 2 - a solar hot water package system is delivered to the site and the collector raised to the roof where it is mounted and piping drilled through the roof. Many cities require licensed roofers to mount solar collectors. Good mounting hardware, flashing, and sealing all roof penetrations will assure leak-proof construction. The installer works from the collector down into the tank with piping and final power connections for the heat exchanger.

The installer returns after a day to assure that there are no leaks. A commercial installation can be much larger and needs to be designed by a Mechanical Engineer. Installation may take longer, however, the sequence of construction is very similar to that in a residential application. ASHRAE provides solar heating systems guidelines for commercial solar water heating systems that can be found at the Solar Rating and Certification SRCC Standard website.

Case Study: Fenway Park

Multiple heat exchangers are used to transfer the heat from the solar collectors to the water storage tanks. Photo courtesy of Heliodyne Twenty-eight solar collectors line a roof at Fenway Park, providing hot water for the vendors selling food to the Boston Red Sox fans. The Sox are the first team in Major League Baseball to have a solar water heating system at their ballpark. This system is expected to reduce the park's water-heating energy demand by an average of 30 percent annually. Approximately 36,000 lbs. of CO2 are expected to be offset every year from the newly installed solar system - the equivalent of planting five acres of trees every year. Along with the twenty-eight collectors, the system includes flush mount kits, thirty-two gallons of solar fluid (for a closed loop cold climate installation), four heat-transfer appliances or heat exchangers and four 400-gallon solar storage tanks. Originally designed to heat the water for both the restaurants and the bathrooms, this system is a good example of corporate responsibility. "The Red Sox have a duty and responsibility to help protect and preserve the environment and to help keep the Fenway neighborhood clean and green," said Red Sox President/CEO Larry Lucchino. "The installation of solar thermal panels is the next step in our commitment to endeavor to make ‘America's Most Beloved Ballpark' one of America's greenest ballparks."7 Key Numbers at a Glance Fenway's total annual hot water load 1,132,500,000 BTU's Gross annual solar system energy output 401,500,000 BTU's CO2 reduction 36,000 lbs. annually Average annual energy cost savings $13,583 Cumulative energy cost savings $339,580 (25-year period with est. 10 percent annual utility rate increase.)

 

Diagram of a typical residential solar hot water system Diagram courtesy of Heliodyne

Standards and LEED® credits

The purpose of the Solar Rating and Certification Corporation is "to administer a certification, rating, and labeling program for solar collectors and a similar program for complete solar water heating systems."⁸ Solar collectors are tested for wind load, hail, structural stability as well as thermal performance by third party testing laboratories. They provide guidelines on the use of PEX, sizing, component substitutions and installations. Manufacturers have performance ratings of their collectors certified by the SRRC.

ENERGY STAR provides a list of approved solar water heaters that are eligible for tax credits.⁹ Tax credits are available to consumers at 30 percent of the cost, with no upper limit for the purchase and installaton of an approved solar hot water heating system through 2016 for both existing and new homes. The credit is not availale for heating a swimming pool or a hot tub, it is meant to offset the heating for domestic use in the home.¹⁰ For residential installations, there can be a good rate of return on the homeowner's investment. With the included Federal tax credit, most homeowners can expect to recoup their investments within eleven years or less.

It is not as easy to predict the ROI on commercial installations. In the home, or in a small hot water system, professionals report savings as much as 80 percent off of their water heating bill in Hawaii, a warm, sunny climate, to 50 percent in Alaska. According to Heliodyne's Pilgaard, "The professional should find the balance between the size of the system and the offset savings. To analyze what is correct, the bigger system might not be the best investment."

In LEED® 2009, professionals can receive credits in many categories. Solar hot water is a renewable energy system that with the rising cost of fuel, particularly in sunny climates, makes sense as a primary tool for energy savings.

PROVIDING ACCESS TO DAYLIGHT AND THREE- DIMENSIONAL WINDOW DESIGN

Recognizing the environmental impact of energy-efficient windows is a good part of designing an energy-efficient building envelope. An energy-efficient window is a synergy of its components. Maureen Faccia identified these components as the "three dimensions of energy-efficient window design." These include the glass, spacer and the frame. The professional should choose a window that has good performance in all of these dimensions.

Glass, Spacer, Frames

Single-pane, double-pane and triple-pane - windows can be chosen with many types of glazing. Maureen Faccia recommends that professionals log into a web tool provided by the Efficient Windows Collaborative.¹¹ This site was developed jointly by the Center for Sustainable Building Research, at the University of Minnesota, the Alliance to Save Energy and the Lawrence Berkeley Lab and provides descriptions of how energy-efficient windows work, information on building codes and numerous resources for manufacturers as well as for the professional. In order to compare costs for a typical house, a map of the United States broken into four climate zones is provided and by selecting on a city nearest to your location, the annual energy use from computer simulations for a typical house in your city can be compared for different window options.¹²

Diagram of the three dimensions of window design that includes the glass, spacer and frame. Photo courtesy of Milgard Windows & Doors

The glazing in a window means the difference between keeping cool in the summer and warm in the winter, reduces condensation and protects finishes and furniture from fading from the sun's rays. Dual-pane designs use an air- or gas-filled space between two panes of glass. This insulates much better than a single pane. Special Low-E coating on the glass blocks infrared light and filters damaging ultraviolet light (UV). ENERGY STAR describes the anatomy of an energy-efficient window¹³ and labels those windows which meet set energy performance criteria. The ENERGY STAR label is an independent third party certification from the National Fenestration Rating Council (NFRC). U-factors, or the rate of heat transfer, generally range from .0.25 to 1.25 and ENERGY STAR also provides a map with four climate zones for selecting the appropriate U-factor for your region, identifying approximate dollar savings per region.¹⁴ Choosing a Low-E glass contributes to energy savings by deflecting heat before it enters the occupied zones of a building.

Additional NFRC ratings are provided for the Solar Heat Gain Coefficient, Visible Transmittance, Air Leakage, and Condensation Resistance. Windows are rated with respect to performance of the glass within the unit. Insulating spacers between the panes of glass reduce heat transfer and prevents condensation. Early single-paned windows in metal frames had to be scraped of frost on the inside to peer out into a cold winter day in the 1950's. Condensation in southern climates, warped wood frames and provided a breeding ground for mold and mildew. A spacer keeps a window's dual-glass panes the correct distance apart for optimal airflow between panes. Too much or too little airflow can affect the insulating glass efficiency. The design and material of the spacer also can make a big difference in the ability to handle expansion and contraction and thus reducing condensation.

Along with performance, one of the most important aesthetic decisions to make when choosing a window is the frame. A window frame holds the sash or casement and window hardware. A properly designed frame helps minimize thermal transfer throught the window. Engineered for performance, new vinyl and fiberglass frames are available with chambers within the frame that enhance strength, noise reduction and have a greater insulation value. These frames provide a wide palette of colors, and design styles.

According to the Denver AIA Committee on the Environment, in the Sustainable Design Resource Guide, "Fiberglass frames have a low embodied energy, their thermal performance is comparable to wood and vinyl, and it is durable and maintenance free. The cost is presently comparable to a good wood window. More common are fiberglass doors with insulating cores which perform as well thermally as steel insulating doors."¹⁵ Fiberglass frames are available for both commercial and residential projects. Pultruded fiberglass window frames are manufactured from raw materials that include liquid resin, fillers, specialized additives and reinforced fibers. This process also uses limited natural resources. Based on product longevity and its low pollution levels during manufacturing, in 2007, the EPA labeled pultruded fiberglass environmentally friendly. Professionals can address energy efficiency, sustainability and green through producst as well as processes by choosing a fiberglass frame for energy-efficient windows.

Both vinyl and fiberglass frames are available that meet both ENERGY STAR as well as the stimulus package requirements for energy efficiency. Currently, there is a tax credit for homeowners up to 30 percent the cost of a window package up to $1500 per homeowner for replacement windows. To qualify, windows must have a U-Factor and SHGC of .30 or better. By providing metrics, testing and labeling, the NFRC assures that windows will work as specified by the professional who chooses an ENERGY STAR NFRC labeled window.

Fiberglass frames are available that match the beauty and profile of solid wood windows, while providing the durability and performance advantages of fiberglass. One of the primary advantages of this material is that it is made of glass. These frames expand or contract at the same rate as the glass it holds. This leaves less stress on the entire unit, increasing its longevity and durability.

Peter Ewers, AIA, LEED AP, principal of Ewers Architecture in Golden, CO, says that his "firm has specified fiberglass windows on several projects. We like the high performance we receive from these windows, and the strength of the assembly. And since fiberglass is essentially spun sand, we feel the embodied energy and other sustainable attributes are better than many of the alternatives."

FANS: PRACTICAL, EFFICIENT AND BEAUTIFUL

Many times professionals are divided between specifying highly designed building features or the common energy saving equipment that just "does the job." A technology first developed in the 19th century industrial revolution, ventilation fans are now available that meet both a professional's desire for high tech and great design. Until the past decade, most ceiling fans in the market were reproductions of Victorian models - primarily used in the home. Today, recognized industrial designers are providing professionals with designs for every style, from traditional to minimalist. There are fans that are designed for both the dining room in the home as well as the board room in commercial offices. New fans can be customized to have different blade configurations, blade size, and colors. Many provide remote controls for users as well as light source controls.

Some designers are recognized artists in their fields and like mid-century modernist designers, Charles and Rae Eames, are proud to bring design into ordinary objects. However, some designers have reduced fan efficiency for decoration. According to Rezek, "People assume that all contemporary fixtures are more functional than traditional ones, that is because contemporary fixtures are easier to clean and they seem to be more utilitarian based on their appearance. And because of their simplicity and lack of ornamentation, they also have an alliance with the industrial look. But all of this doesn't necessarily translate into function."¹⁶ It is important to select ceiling fans for efficiency as well as design.

In the Los Angeles W Hotel lobby, this ceiling fan provides visual and sculptural impact to this commercial space. Diagram courtesy of The Modern Fan Co.

 

New fans are quieter and can be damp rated for outdoor applications and used in hotel balconies, porches and outdoor linnaes. The overall benefits of using fans are that they:

• Use low energy.
• Reclaim warm air trapped against the ceiling as a method to bring air down and equalize air temperature in a stratified interior space.
• Offset or supplement use of air conditioning.
• Provide individual environmental comfort - through the feel of air movement.

Use low energy

"Ceiling fan/light combination units that have earned the ENERGY STAR are about 50 percent more efficient than conventional fan/light units."¹⁷ ENERGY STAR-qualified ceiling fans use improved motors and advanced blade design. The DOE has required that all fan manufacturers now publish data on energy use for this equipment. They also publish information on how to select the right size for a room, the appropriate mounting system as well as installation information.

ENERGY STAR provides descriptions of fan motor types, housings, blades and grades of motors by performance. Fan motor size, rotational speed, control types and blade weight and shape all impact performance.

Air stratification and aesthetics

Warm air rises and cold air falls. When heating or cooling a room, thermal imaging can provide a thermal map of the room temperature that shows that air stratifies in layers across an enclosed space. A ceiling fan will move air downward and cause the layers to mix, equalizing the temperature in a room. In cool climates, during the heating season, warm air trapped against the ceiling can be reclaimed to reheat occupants below. In the cooling season, cool air is distributed around the room through this deliberate air movement. Ceiling fans can also be chosen for their beauty, as well as for air distribution and energy efficiency. They highlight the ceiling space, which is often an aesthetic dead zone.

Air movement: an exothermic event

Although studies show that people spend more than 90 percent of their daily life indoors, there is still a need by most people to have a connection to nature. Moving air makes people feel better and air movement draws heat from the body in an "an exothermic event". According to Dave Ellis, National Sales Manager of The Modern Fan Co., professionals can "potentially set a thermostat as much as 8 degrees higher when a ceiling fan is specified, from 72 degrees to 80 degrees." The end result it that the occupant still feels as though the space is cooler, a result of the sensation of moving air of which there is a strong psychological association with a cool breeze. The actual net effect of cooling or heating air is negligible but the association of moving air with the temperature of the air is a documented response by humans.

In the future, ceiling fans will become even more energy-efficient and are "pushing the envelope on efficiency standards," said Dave Ellis. Some fans are made of recycled materials, some use compact fluorescents and there may be LED installations in future fan designs. Used inside, outside, in the home and at work, ceiling fans are an affordable technology that can have a big impact on energy savings.

HIGH-PERFORMANCE AIR DISTRIBUTION
- RAISED FLOORS

"The majority of energy savings comes from the reduction of the ductwork in a building."
- Scott Alwine, LEED AP, Marketing Manager at Tate Access Floors.

Raised floor with Underfloor Service Distribution (UFAD) systems provide high-performance benefits in a multiple of ways:

• They significantly reduce the amount of HVAC ductwork by
  creating an air delivery plenum at each floor.
• They reduce the space required for service distribution, saving materials and allowing for additional daylighting.
• They save on retrofits and office churn, allowing owners to move walls and workstations while providing a flexible wire, cable and mechanical system that can be rezoned easily.

UFAD systems were invented to meet the needs of data centers and soon other high performance guilding owners incorporated this system into the design of commercial offices, libraries, K-12 schools, universities, and gaming floors. "There are a lot of benefits to this technology for high performance buildings, particularly those that incorporate modular wiring and cabling with underfloor air," said Tate's Scott Alwine.

Saving energy

Three of the most important energy savings provided by underfloor air distribution include:

• The stratification of air in the space that requires only part of the load to be conditioned.
• The reduced air pressure resulting from the air delivery plenum and the associated reduction in fan horsepower requirements.
• The warmer supply temperatures that allow for increased use of fresh air and the extended use of the economizer cycle.

A raised floor uses steel panels on pedestals approximately 12" to 18" above a floor slab to create a pressurized air delivery space. Air is then delivered to the occupied zone through movable diffusers. These diffusers allow for personal comfort control as the occupant can open or shut the air vents to supply the level of air as needed for comfort. In addition to personal control by locating these diffusers in the occupied zone the user is also gaining first benefit of the fresh air and increased ventilation.

Overhead systems force cool air from above mixing the entire space to the set thermostat temperature. Therefore, the entire heat load of the space must be used to calculate the CFM requirements. In a UFAD system air is delivered from below with very little mixing so only the load affecting the 6 foot occupied zone is used to calculate for the system CFM requirements. This reduction in load maintains similar CFM requirements for both systems.

In a ducted mechanical system, forced air is provided through diminishing ductwork. As a duct gets smaller, the force needed to push the air is larger, typically requiring significantly more pressure. One of the greatest savings of a raised floor system is that the large fans and motors to distribute forced air can be reduced in size and power.

Additional savings are achieved through the use of underfloor air distribution, particularly in moderate climates as the air provided to the plenum from the central HVAC system is delivered at 63 to 65 degrees allowing more fresh air to be introduced into the system through longer economizer operation. Overhead systems provide air at a constant 55 degrees and that 8 degree difference adds to the savings in the use of the chiller for air conditioning.

The importance of early integration and design details

The integrity of the plenum "is one of the most important aspects of designing, contructing and maintaining an underfloor air delivery (UFAD) system."¹⁸ An integrated approach to the design of an UFAD system will include these stages of the design and construction cycle:

• Design:Specifications and performance requirements for plenum sealing integrity should be included in all divisions of the CSI (Constuction Specifications Institute) specification. Drawings detailing the construction requirements for the UFAD plenum should be provided to the contractor.
• Pre-bid Meetings should be required to inform all subcontractors of plenum sealing including the requirements for mock-up construction.
• Pre-construction Meetings should be specified to reaffirm the plenum sealing requirements to each awarded sub-contractor.
• Mock-up: Specify the construction and testing of a mock-up that includes all actual building conditions and components that penetrate walls, floors and in particular electrical and mechanical closet areas.
• Quality Inspection: Specify the use of a commissioning agent to audit the construction process, perform air leakage testing on the mock-up and final installation and provided detailed reporting to the General Contractor that the UFAD system follows the specified Requirements.¹⁹

Manufacturers will provide guidelines and assistance with specifications and testing criteria in order to assure the maximum performance and integration of an UFAD into the building.

Meeting standards

The Ceilings & Interior Systems Construction Association (CISCA) recommends testing procedures for access flooring. These tests include structural loading, impact, and air leakage through panel seams. As the market for raised floors becomes increasingly global many manufacturers are expanding their performance reporting criteria to include more internationally accepted practices such as static system testing in addition to panel only tests. Manufacturers will provide product performance guides and assurances that the raised access floor system is tested by a certified third party.

Saving space

Often value engineering will focus on the reduction of the amount of building that is to be constructed. By reducing the cubic feet of construction, the cost savings are incrementally a larger part of any cost analysis for saving money. With a raised floor and underfloor service distribution the developer has the option to either reduce the slab-to-slab dimension or provide a higher ceiling for tenants. For example if the air plenum is from 12" to 18", and the ceiling plenum is designed for lighting, and infrastructure that does not include the crossing of large ducts that may need to cross over each other, the ceiling can be 6" to 12" higher in the same area, or conversely, the developer can reduce the slab-to-slab height of the building by the same amount saving significant core & shell materials.

Detail of plenum for a typical through wall conduit poke-thru used for service distribution. Diagram courtesy of Tate Access Floors

Churn

The International Facilities Management Association (IFMA) has studied the effects of change on the cost of facility management.²⁰ The Churn rate, that constant change over of tenant space can be as high as 41 percent. The cost to reorganize office space is well documented. Raised floor systems have a great advantage to building owners as this system is flexible and provides easy retrofits for building owners. Re-arranging offices, moving wires and cables, adding sockets is as easy as swapping out a solid floor panel with a panel with wire access or an infill panel to replace the moved diffuser panel. Because the power sources and air distribution system are terminated in a flexible raised floor, there is no need to core drill through a slab or move a power pole to renovate an office layout.

Part of a LEED® strategy for environmental design

As part of an integrated thermal delivery system, LEED® 2009 IEQ Credit: Controllability of Systems - Thermal Comfort 6.2 mentions floor diffusers as one means to allow individuals to adjust and control their own comfort level in an indoor environment. In addition, UFADs also provide LEED® credits in numerous other categories. Most systems are made from recycled materials and in addition, they qualify for using low-emitting materials. These systems increase ventilation, are energy efficient and provide individualized thermal comfort.

CHOOSING FOR ENERGY SAVINGS THROUGH AN INTEGRATED METHODOLOGY

The relationship of all of these technologies is that they all allow for energy savings and opportunities to expand the professionals design vocabulary. Designers can select a number of strategies to make a building use less energy. It is a collection of many components that create an energy-efficient building system. Professionals can choose the means to answer the call from the President to meet one of the greatest challenges of the 21st century - how to save energy both in our offices and in our homes.

"When it comes to saving money and growing our economy, energy efficiency isn't just low hanging fruit; it's fruit lying on the ground," said Secretary Chu. "The most prosperous, competitive economies of the 21st century will be those that use energy-efficiently. It's time for America to lead the way."²¹

 

Endnotes 1 www.energy.gov/news2009/7550.htm 2 modernfan.com/pressroom/pressRelease_ronRezek.html 3 www.metaefficient.com/news/solar-water-heaters-now-mandatory-in-hawaii.html 4 www.metaefficient.com/news/solar-water-heaters-now-mandatory-in-hawaii.html 5 http://www.energy.gov/news/6134.htm 6 wholeearth.com/issue/2015/article/380/climax.solar-water.heater 7 boston.redsox.mlb.com/news/press_releases/press_release.jsp?ymd= 20080519&content_id=2730414&vkey=pr_bos&fext=.jsp&c_id=bos 8 www.solar-rating.org/ABOUT/ABOUT.HTM 9 www.energystar.gov/index.cfm?fuseaction=solar_wheat.display_products_html 10 www.energystar.gov/index.cfm?c=products.pr_tax_credits#s11 11 www.efficientwindows.org/selection.cfm 12 www.efficientwindows.org/selection.cfm 13 www.energystar.gov/index.cfm?c=windows_doors.pr_anat_window 14 www.energystar.gov/index.cfm?c=windows_doors.pr_crit_windows 15 www.aiasdrg.org/sdrg.aspx 16 modernfan.com/pressroom/pressRelease_ronRezek.html 17 www.energystar.gov/index.cfm?c=ceiling_fans.pr_ceiling_fans 18 Tate Access Floors, "Architect's Guide for Detailing & Specifying Access Floor Air Plenums" 19 Tate Access Floors, "Architect's Guide for Detailing & Specifying Access Floor Air Plenums" 20 www.ifma.org/tools/research/proj_mgmt_bench.cfm 21 www.energy.gov/news2009/7550.htm

 

Celeste Allen Novak teaches as an adjunct professor at Lawrence Technological University and is principal at RizzoloBrown & Novak Architects.