3 ms·
US and Australian units are different for insulation, but in my terms the insulation around the best ducts is R1.5, but good ceiling insulation is R6. 4x differ
by fifteenforty 4y ago
US and Australian units are different for insulation, but in my terms the insulation around the best ducts is R1.5, but good ceiling insulation is R6. 4x difference
Edit: not to mention the huge difference in surface area. Ducts can expose your conditioned air to a huge, poorly insulated surface. Bad for efficiency.
- briHass 4y agoInteresting. The code for duct insulation in unconditioned spaces in the US is R8, and they're pushing for higher currently. They also recently undid a long held myth about ducts buried in insulation leading to condensation issues. Most areas now allow ducts to be buried as long as you have R19 above and below, or R30 above. When I just installed a ducted mini for 3 upstairs bedrooms, I surrounded my R8 flex duct with R30 insulation.
- EricE 4y agolol - it's not a myth. It's physics: https://www.youtube.com/watch?v=Vufih-WN5R4 https://www.youtube.com/watch?v=Vufih-WN5R4
- mrexroad 4y agoFwiw, context of this video is metal duct work. You’re not going to see R-8 flex duct buried in R-30 begin to sweat when the AC is running. In terms of controlling the dew point, the duct is no different than the conditioned space at that point. Like you said, it’s physics.