Discussion in 'Fine Living, Home, Design & Auto' started by Douglas, Jan 31, 2012.
Not if you live somewhere cold
Strictly speaking, an air conditioner is a kind of heat pump. It just goes one way -- cooling. Is a "heat pump" any different in how it cools air, or is it just acting as a regular air conditioner? I have no idea, but I tend to think it's pretty much the same thing.
Also, medwed, ducts and no ducts isn't a question of heat pump or furnace; it's just how it's laid out -- you might be thinking of a mini-split (a ductless, split air conditioner or heat pump).
The part I'm trying to figure out is how anything supplies HVAC without ducting.
If you only have a couple rooms (and you're surrounded by conditioned space on five sides like many apartments/condos), you might be happy with just one or two "heads."
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.
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.
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.
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.
That makes sense. I guess that's part of the "charm" so many folks don't think about with old buildings.
Medwed mentions Europe a lot, if that's what he refers to, old and new house here are not build with ac ducts. Offices are, and old patrician houses that are used as offices often have ac retrofit, which looks hideous with respect to the house.
And as I understand it a heat pump here means one that uses earth warmth. In summer it pumps up cold water from the deep and uses that to cool the floor/ central heating, I. Winter the water below is warmer than ambient temp so uses less energy to get heated up.
Mine has ducts, 1 inch in diameter inside the brick walls. Split AC is perfect for retrofitting. I used to live in US in many places with central AC and all of them, without exception, inefficient, slow and prone to noisy operation. Not to mention the losses through giant corrugated pipes and ducts and all aesthetic intrusion. Plus those AC units that people put in their yards and on the roofs , why do they look so huge? My AC unit for 850sqf apartment looked like a giant commode. BTW, no cycling with split AC units, all depends on the program you select. Use it for heating too, until it gets below 20F.
The 1" pipe is a refrigerant line, not an air duct.
Also, central air is loud but it's only loud in certain places whereas the mini-split is going to make noise where you need the air delivered.
Yeah, you cannot isolate noise with the mini-splits. I have two five ton central units and I hear neither of them from within the house.
To bump this thread, here's a picture of some lizards hanging out in my fuse box.
Anyone sick of LED bulb questions up in here? Good! I have another one. Has anyone used LED light bulbs for exterior wall mounted fixtures? I have converted most of the overhead lighting in our house to LEDs except for lamps (wife is resisting) and the exterior lights are the next to go. I am going to get some exterior flood light bulbs and the fixture lights are the issue as LED seem to be better at directional light than spread around.
These fixtures probably cost us the most in terms of electricity as there are 3 bulbs in each fixture, we leave them on all night, and it looks like we are trying to be a light house for ships at sea.
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