"Shamoononon drives like a farmer" (shamoononon)
04/25/2020 at 15:04 • Filed to: duhfook
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"Shamoononon drives like a farmer" (shamoononon)
04/25/2020 at 15:04 • Filed to: duhfook | 0
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I live in a small condo building with two stories. Although we live in so cal it’s a particularly warm microclimate surrounded by open space. I installed AC a few years back because I was suprised by how hot it got. My downstairs neighbors don’t seem to be as bothered by it. I know they are probably cooler because they are downstairs, but is it possible my AC is spending energy cooling their unit too? I cool my air, theirs rise into my unit, etc.
RamblinRover Luxury-Yacht
> Shamoononon drives like a farmer
04/25/2020 at 15:39 |
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My extremely idle guess would be that you having the roof overhead soaking up sun makes up for most if not all of the difference, but it’s also possible there’s either convection (air passing from their unit into yours) or conduction (your unit’s floor cooling their ceiling) making for a situation in which your A/C is cooling their unit. To an extent - the conduction thing would depend on their being very little insulation and materials that conduct heat well - i.e. not a slab.
The reason being, that the more insulation you have, the hotter their unit would have to be to be cooled by yours - and unless their unit is “comfortable” to them at 7-8F hotter than yours, not as likely.
If it’s slab construction with metal framing or masonry walls, air contact between floors isn’t as likely. If it’s metal frame only or wood frame - there absolutely can be some. A lot, even.
facw
> Shamoononon drives like a farmer
04/25/2020 at 15:57 |
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Seems like it’s not likely there’s too much air flowing between the units, so I’d imagine that sort of cooling is limited (though obviously that depends on construction quality, and whether there are any connected vents or whatever). There certainly can be heat transfer directly through the floor or ceiling, but that depends on materials and in sulation quality. You’d expect some difference from just only having hot on the four walls instead of the four walls and the ceiling/floor. The fact his roof is in the shade (of your apartment) while yours is in the sun surely makes a big difference as well.
The Snowman
> Shamoononon drives like a farmer
04/25/2020 at 16:04 |
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Unless the floor is insulated very well you are helping out the downstairs folks. My house had a flat roof and then a peaked roof built above 50 years later. When I installed an attic fan between the two roofs it made a massive difference in internal house temps. Yours would not be as big but if there is any gradient in temperature it will try to equalize. Also don't think of it as you cooling the downstairs as energy goes from high to low so if you are colder they are just heating your place :)
RacinBob
> Shamoononon drives like a farmer
04/25/2020 at 16:05 |
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Ditto Rambling Rover’s comment. You have a 120 degree roof on the top of your condo. Your downstairs neighbor has your 71 degree on the top of his condo.
In terms of solar load your roof + one wall are always in direct sunlight. Whereas your neighbor only has one wall in direct sunlight. Your place probably has twice the solar load compared to his.
Snuze: Needs another Swede
> Shamoononon drives like a farmer
04/25/2020 at 16:06 |
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Ramblin Rover nailed it. I used to live on the top floor of a high rise and had the same issue. I also dabbled in marine HVAC design at a previous job and solar loading was always killer. Having the sun on your roof and potentially 1 or more exterior walls adds TONS of heat energy.
Additonally you may be losing some heat to the apartment below you, but its negligible compared to the solar load.