The Upside-Down Office

From the Bottom Up

Buildings are increasingly being built with raised flooring because it provides a supply plenum for fresh-air distribution and ventilation. Under-floor air distribution systems can be designed to carry an office’s heating, ventilation, and air conditioning components. Under-floor systems can sometimes require less ductwork (ceiling-based systems often route ducts around or through structural beams, which wouldn’t be necessary in an under-floor space designed for the purpose) and are easier to access. And it can also create a healthier and more comfortable environment for the occupants of the space, which tends to have long-term benefits for businesses.

The biggest benefit of under-floor systems, Johnson says, is that they deliver fresh air closer to occupants than ceiling systems. Fresh air rises from the floor and reaches the occupant more quickly and efficiently, he explains. Holland adds that when under-floor air distribution is done correctly, the layer of fresh air across the floor can help reduce the contaminants in the occupied space because it is not mixing with the less-fresh air that has risen to the ceiling. That could, Holland says, contribute to a more comfortable, healthier work force. “That can have a definite payback in terms of productivity,” he says.

It can also have a payback in terms of energy costs. Air that is supplied from under the floor only needs to be cooled to 65 degrees, while air supplied from the ceiling is generally cooled to 55 degrees. “You have to cool it down further [when it comes from the ceiling], because it has to go farther to get to the occupied zone,” Holland explains.

Such energy-efficient plans can also help buildings gain points toward LEED (Leadership in Energy and Environmental Design) certification, a standard of environmental efficiency established by the U.S. Green Building Council. “LEED certification gives building a certain distinction that many businesses want,” says Johnson, who has become a LEED Accredited Professional, which means that he is able to facilitate the integrated design process and streamline LEED certification for buildings. “LEED recognizes buildings that are energy efficient, and in theory those buildings would then have more value for resale.”

Even buildings that may never be sold can benefit from incorporating an under-floor air-distribution system into raised access flooring. The energy savings add up over time, says Tom Hysell, principal at Architectural Alliance. “Our clients see the long-term benefits of doing this,” he says. “They recognize that there will eventually be payback.”