Originally Posted by Piobaire
That makes sense and I was thinking about mini-splits too but he had mentioned his place has central AC so was scratching my head.
He also mentions ugly ducts, which I took to mean he's living somewhere that had them installed after it was built. My guess would be that he had the ducts removed when he put in the mini-split(s).
The ducts for my upstairs are in the attic and boy does that impact the cooling capacity. An exterior wall, say, has at most a 30 degree temperature difference and usually something like R15 or so insulation. The attic can 60+ degrees hotter, and the ducts have surface area on all four sides with just R3 or R4 (heat transfers 4-5x faster), and
the air is flowing across them which improves heat transfer.
edit: actually the air in the ducts is cooler than in the house so it's more like 80+ degree difference between the inside of the ducts and the attic.
This thread makes me want to go wrap my ducts with another layer of insulation.
Originally Posted by RedLantern
This. I lived in a old building in downtown Knoxville and just had one in the living room and one in the bedroom and was perfectly comfortable in temperatures 15-100 degrees. Also, the setup was super responsive - I could leave the AC off all day, get home, turn it on, and be cold within 2-3 minutes.
That just means you've got too much cooling capacity. You want the a/c to run more to dehumidify the air and give you more stable temperatures. Plus all that on-off cycling will reduce the life of your a/c more than running continuously would, though that may not be as much of a problem if you're really well insulated (by other people's apartments).
Also, they make mini-splits with multiple heads though I'm not sure how they work exactly.Edited by Ataturk - 8/25/14 at 10:28am