A joist panned duct isn’t the best idea to begin with. Placing one where two LVL’s come together is adding restriction and air leaks.
Nobody wants to find this in the space that affects air quality of the entire main floor of a home. But this is what happens when joist panning is done poorly.
There’s a lot of math that determines how much air can be moved. This duct is light years more efficient than the joist panned duct. The space between the floor joists is far too small. Not enough air could reach the AC unit. This new duct moves the right amount of air. After the project, my customer reported that the main floor had always been too warm in the summer. Now they say its always cool – even on the hottest days.
Code requires ducts in unconditioned space (such as this crawlspace) to be insulated. Otherwise it begins raining. See those floor joists? They’re made out of oriented strand board (OSB). OSB doesn’t like humidity. A permanent rainstorm all summer isn’t helping this home’s structural integrity over the long run.
The AC install on this home is a textbook case of a builder using non-engineering. Good home building is a mix of education and a lot of common sense. If you suspect non-engineering was used somewhere in your home, maybe it’s time for a common sense fix? Call the common sense handyman today.