Heating, Cooling and HVAC

Many people who opt for radiant-floor heating do so because they don’t like forced-air heat. There is a common perception that forced-air heating systems dry out air and generate dust. “Nothing could be farther from the truth with a properly installed forced-air system,” says Betsy Pettit, AIA, of Building Science Corporation in Westford, Massachusetts. Forced-air systems, she argues, offer the benefit of being “all things to all systems.” A forced-air system can provide heat, air conditioning, ventilation, and filtration—all through a single system of ducts and with shared fans. A radiant-floor heating system, on the other hand, only does one thing, according to Pettit, and it does it at a cost that is typically higher than that of a forced-air system serving those multiple functions. “For me it’s just a hard sell,” she told EBN. “If you insulate the slab and if you build your building envelope correctly—that is to say, leak-free—you can be more comfortable for less money with a ducted distribution system,” she says.

Forced Air System Illustrated

Pettit could think of no tract-home builders in the U.S. who install radiant-floor heating, though there are many custom and spec builders who are very happy with radiant-floor heat. Max Strickland confirms that cost is indeed higher for radiant-floor heat—typically 50% higher than for forced-air—but he notes that if you provide the same level of zoning with forced-air, the costs would be much closer. He deals with air conditioning in houses that have radiant-floor heat by putting in ductless mini-split air conditioners made by Sanyo or Mitsubishi, which he says are very efficient. Larry Drake adds that in addition to using ductless mini-split systems, some builders of houses with radiant-floor heat also often put in high-velocity duct systems for air conditioning, in which very small, 3” (75 mm) round ducts can be run through wall cavities. Drake was unaware of any large tract-home builders who have adopted radiant-floor heating over forced-air systems.

Radiant Heating Illustration

Source:http://www.radiant-heat-floor-methods.com