Duct Gains: Why do we hate R-8?
When you start measuring, it is very scary what you start to find. As you can see, like the industry accepted national average, this system is losing 30% of the 3-ton capacity through it's well sealed, but poorly insulated duct system. Unfortunately, the method is not perfect since a hotter day in the attic could cause greater gains. But, that would be the time to sell duct sealing and insulation to the homeowner! Any of you energy auditors out there could probably comment on how much attic ducts effect home infiltration as well. So, why do we hate R-8 insulation? Is it really just the hassle of wrapping the equivalent of a blanket around the ducts? I don't recommend retrofitting a distribution system in an attic in the middle of July, but maybe it makes sense to offer to come back in the Fall? Please, don't just leave it be! Doing so makes it hard for this tree hugger to sleep at night!
Posted by Excess Air