DUCT TESTING AND HERS RATING

According to the Department of Energy, in older homes, the biggest single energy consumer is the HVAC system. Basic research indicates that 30 to 40% of air travels through duct leaks. Energy Star states that duct leakage averages 20 to 30%. The 2010 Energy Codes, which are slated to come into effect in July of 2015, state that duct leakage must be tested and be less than 4% including the air handler. The air handler, by law, is allowed to leak up to a maximum of 2%, so that would only leave another 2% leakage allowed in the entire duct system.

If you purchase a 3 ton air conditioning system, it would produce 1200 CFM’s of airflow, on average. If you have 10% leakage that would be 120 CFM. 20% leakage would equate to 240 CFM’s which is over ½ ton of air conditioning leaking into your attic. If the duct leak is in the return side of the duct system, you could be pulling attic air into your system and trying to cool
and dehumidify it. Hopefully the air filter is at the air handler and not in the return grill or you could also be sending that attic air unfiltered into your home.

The recommended method for duct leakage testing is to use a duct tester to determine exactly how much air is leaking out of the ducts. If used in conjunction with a blower door it can determine exactly how much air, in CFM’s, is leaking to the outside or into your attic. This is the method approved by both BPI (Building Performance Institute) and Resnet, the two National organizations that analyze and rate homes for leakage, both duct and structural, safety and efficiency.

As this is such an integral part of the air conditioning system and its effect on your home or building, it seems that this would be a major concern for air conditioning contractors. An Air Conditioning license in itself does not certify a company for duct testing. A few years ago, the State of Florida had a rebate in effect for air conditioning systems but the duct system had to be tested and could only be certified by a Resnet HERS rater or a BPI Building Analyst. A regular air conditioning contractor could not certify the duct system.

At Dunedin Refrigeration, I am a certified Resnet HERS rater as well as a certified BPI Building Analyst. This is the way that I can do the best job possible for our customers because I have gone the extra steps to make sure that every part of the system is working correctly to provide the cooling and the efficiency that you are paying for. We don’t just settle for the minimum required, we strive to be the best for our customers.

We are certified to do the job right: