"Renovating this historic home doubled its size from 2,300 sq. ft. to 4,700 sq. ft, yet the energy bills remained virtually the same. That's huge."
"A right-sized system combined with proper air sealing creates a healthier house. Together, the two will maintain a comfortable humidity level, reduce the occurrences of allergy-causing mold and help keep dust and pollen outdoors. The health ramifications are significant."
"This remodeling project resulted in a very healthy, air-tight home. Many green building programs set a target of changing one-third of the air from indoors to outdoors, or 0.33 air changes per hour. I got it down to 0.27 changes per hour in this home. That's a difference the homeowner will feel."
When it comes to sizing the HVAC system, bigger is not always better. This notion defies conventional rules of thumb. It can take some convincing to get contractors on board.
"Air conditioners cool a house first, then dehumidify it," says Seville. "In a humid climate like Atlanta's, this function is particularly important. If an HVAC unit is too large, it will short cycle. That is, it will turn on, cool the house down, and turn off again before removing much humidity from the air. Frequent starting and stopping increases energy consumption, makes the home uncomfortable, and contributes to mold and indoor air quality problems."