Room on second floor of house that cannot be cooled with AC.
We have a 40 year old house with a 7 year old central air unit. The duct work makes it difficult for the AC to keep the upstairs as cool as desired on extremely warm days (92+). We have dual zone thermostats so we just use the upstairs unit for AC, which helps. We recently replaced the windows and have insulated the attic, so overall the system is adequate. We do, however, have one room that consistently runs 8-10 degrees warmer than the rest of the second floor. Cool air is coming through the register. The two biggest issues that I can determine are 1)this room sits directly over our outdoor porch and 2) we have a 40 year old oak parquet floor. On 95 degree days, the floor feels like it is 95. Are there insulated floors that can be put in that would do a better jib of keeping the floor heat out? Thank you. Tim
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If the floor over the porch doesn't have insulation in it, of COURSE you will have comfort issues in that room. It's usually possible to blow insulation into the floor joist cavities without a major demolition & repair or a complete re-flooring, drilling & patching blowing holes in the porch ceiling.
I'm not anticipating moisture issues with an insulation retrofit, but to be thorough, what is your location or climate zone?
https://www.greenbuildingadvisor.com/sites/default/files/images/DOE%20climate%20zone%20map.preview.jpg
Thank you. When we had the Eaves and Soffets redone two years ago we had insulation put directly below this room for this. In Chicago so summers typically carry some good humidity. Thank you.
It's a parquet floor... how is this relevant? Is it not a floor with joists and a subfloor? Or is it somehow prone to a lot of air leakage through the floor? When they put insulation in the floor, how did they do it, and how much did they install? To do fiberglass batts nicely, they would have had to take down the ceiling below to install them. Or, did they blow in loose material? How thick is it?
If you can post some photos of the house and the room, that might help.
Oh, and how large are the windows in the room and which direction do they face?
The floor shouldn't feel hot if it's both insulated and air tight. How was it insulated?
The Insulation is fiberglass bats that were placed in from below before the eave/soffet was replaced. There are two windows - total 48 X 28. Window faces South. Relevance of Oak Parquet is thin, old, and very many (they are small) 4X4 or 6X 6. Thank you.
Tim,
We're all guessing here. But there is a good chance that (a) the fiberglass batts aren't thick enough to completely fill the joist bays, and (b) the fiberglass batts have slumped away from the subfloor, leaving an air gap at the top of the fiberglass batts, and (c) you have an air leakage path that is bringing hot outdoor air to the space above the insulation.
But this is just a guess. As Dana wrote, something is wrong with your insulation installation, the air sealing work, or both. As experienced home performance contractor should be able to investigate the situation and suggest solutions.
Thank you.
If you're going to replace the flooring you can drill the subfloor and dense-pack cellulose between the floor joists, packing it out completely, which would also substantially reduce any air infiltration happening there.
IRC code minimum for exposed floors in US climate zone 5 (N-IL) is R30 betwen the joists, "Or insulation sufficient to fill the framing cavity, R-19 minimum".
http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_11_sec002.htm
If the installers for some reason didn't air seal the stud bays and left a vent space under the subfloor with soffit vent as if it were a roof, that's an error that can be corrected with dense-packing from above before re-flooring.