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.
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Sponsored by Heliodyne, Milgard Windows & Doors, The Modern Fan Co., Tate Access Floors
Celeste Allen Novak AIA, LEED AP

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.

 

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Originally published in GreenSource
Originally published in July 2009

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