While I am not in canada, I am in phoenix (desert climate). I can tell you that I insulated my attic ductwork and realized a savings of around 25 percent in the hot months. comfort was also greatly improved!!!
I used r13 fiberglass times two wraps (r26??) and a reflective vapor barrier on the outside, after using about a ton of mastic to seal the outside of the ducts. The delta t from the air handler to the furthest register was a drop of about 30 degrees before the wrap. after the wrap (and some flex duct taken out). Now the delta is only 10 degrees on the hotest day on the farthest run (5 ton 2 story house, with all metal ducts.
The cost per foot is a question that I never even considered. I just did it... The labor was not fun, but I did the labor and I know its right.
bottom line,
1. duct seal the outside
2. fiberglass insulation on the outside
1 + 2 = 25 percent savings.
bobinphx
I used r13 fiberglass times two wraps (r26??) and a reflective vapor barrier on the outside, after using about a ton of mastic to seal the outside of the ducts. The delta t from the air handler to the furthest register was a drop of about 30 degrees before the wrap. after the wrap (and some flex duct taken out). Now the delta is only 10 degrees on the hotest day on the farthest run (5 ton 2 story house, with all metal ducts.
The cost per foot is a question that I never even considered. I just did it... The labor was not fun, but I did the labor and I know its right.
bottom line,
1. duct seal the outside
2. fiberglass insulation on the outside
1 + 2 = 25 percent savings.
bobinphx
