HVAC: Size Matters PATH Case Study

Click here to visit the PATH website. The Project: Historic Home Renovation. This 1918 home in an historic district in Atlanta was expanded by 2,400 sq. ft. using energy efficiency principles. Proper HVAC practices significantly reduced the home's energy use and improved indoor air quality. The project won the 2006 NAHB Green Project of the Year award for the remodeler, Seville Consulting. "When I remodel a house, I look for every opportunity to incorporate energy efficiency because I know this will result in a quality, healthy home, which appeals to every homeowner," says Carl Seville of Seville Consulting, Decatur, Ga. "One key step is properly sizing the HVAC system using the industry standard, Manual J." The Air Conditioning Contractors of America's (ACCA) Manual J, Residential Load Calculations, is the accepted industry standard, approved by the American National Standards Institute, for the proper sizing and selection of HVAC equipment in residential homes. "How many customers have asked for a Manual J calculation?" asks Seville. "To date: exactly none. My customers may not realize the mechanics behind the scenes, but they sure are happy with the end result. Properly sizing HVAC systems in well sealed and well insulated homes leads to satisfied and comfortable customers, lower initial and operating costs, reduced callbacks, and healthier indoor air quality."  PDF Click on the image above for a full-size version. Cost "Is it faster to skip the load calculations and use a rule of thumb? Yes," says Seville. "Does it compromise the home's quality? Absolutely. "The less time a remodeler takes to make a sale, the better off he is from a business standpoint, but to really evaluate a house, you need time. And time costs. Then again, we've been in situations where we could take a ton or more off the HVAC system by properly designing a system based on insulation and air-infiltration rates. That means significant cost savings on the equipment. "Load calculations cost approximately $100 or $200 per house and take between one and two hours for an average home," he adds. "This cost is often recouped immediately, because the system can typically be downsized. If a number of homes with similar plans are being calculated, costs are even lower."   1 | 2 | 3 | 4  NEXT