Quote:
Originally Posted by Nevyn
That's why I mentioned it - I figured there was SOME problem I'd forget about.
Anyway, we're looking at going with a 12,000 BTU unit over the 18,000. It says the 12k is for 300 to 500 square feet.
We're more concerned with heat than cooling. Would putting that in a space around 550 square feet be over-taxing to the unit? It's job wouldn't be primary heat, but merely to help hold temperature once the furnace has the area up to temp (from overnight low).
|
I really hate to see people waste their money sooo.
People often discount or totally ignore stratification of air when heating/cooling two story homes. As silly as this may sound, (IF!) you have an open (no door at the bottom of) stairway and you are considering only one unit (mini split) and are looking purely at saving money as opposed to requiring more comfort (as was 42's initial concern) you may be better off putting the unit upstairs in as open an area as possible. Over heat the upstairs a few degrees with the combined output of your boiler and this unit set a few degrees higher which would in effect cause an insulating buffer zone akin to adding more insulation in your attic. I can only guess that is why 42 is so happy with his. Well that and it was quite a find as far as specs and price are concerned.. (KUDOS to 42 for the find) I would buy three of those separately over a three zone multi split.
Excuse the over explaining but, my Mother owns a over under duplex. My brother currently rents the upstairs and keeps his heat at 62 all the time. They both have the same make and efficiency furnaces except for size. Hers being forced air gas 93% AFUE 75000 btu out. His the same , but 48000 btu out. She needs to keep hers set at 70-72 to keep it comfortable downstairs. Last month (DEC) here in central NY was cold as usual. He used exactly half the therms gas as her 92 his vs 184 hers. These apts are not open to each other so I can only surmise that the 8-10 degrees delta T and the fact that he has some insulation over head in attic where as there is none in her ceiling between apts that her heat is indeed supplementing his. They are both same sq ft same layout.
My mother saves everything and I was able to prove this with old bills when previous tenants lived there and kept a much more reasonable 70-72. The difference was only 67% on average as opposed to 100%.
Now this can be used for A/C as well. At my previous house (I am currently back home with Mom) I was able to cool one upstairs bedroom and the whole downstairs from 88in 92out to 66in bedroom 78downstairs all with one 6000BTU window unit running max. I covered all the registers, supply and return with cardboard and tape. Placed a box fan at the bottom of the stairway in a fashion that blew the cool air in a complete circle around the downstairs. I watched in amazement with a lit cigarette as the heat was brought around and went up the stairway with an almost chimney like draw as the cool air flowed down the stairs like a waterfall.
NEVYN.
This is why if you use only one unit (and I would buy 42's 12000btu Amcor) I would suggest an upstairs open area with room doors open if possible over downstairs. At least for the first unit. Who knows, maybe next year another for downstairs!! and No boiler.
One thing I thought of, but have no answer to is if it would be cost effective to have your boiler kick down (setback) overnight as I am not familiar with how quickly one pipe systems can recoup. If your bedrooms are upstairs this may be another money saving option we use in CNY with forced air. I do know that with boilers and radiant floors it doesn't work well.
Anyways I just have this feeling that if you put the indoor unit downstairs as you propose, you will not only be asking a 12000BTU unit to heat your 588sq ft downstairs, but also effectively half of your upstairs through convection. In which case YES you would be over taxing it. In which case I believe you would be better off taking the $1500 (per 42's install) and renting a blow in cellulose machine and putting as much as feasible in you attic. Caulk any infiltration areas. It would be money better spent.
As always my opinion is just that. I always appreciate any feedback as that is how I learn. With the exception of the statement about resistant heats efficiency vs heat pumps JMags has been (in my opinion) spot on and maybe he can add or subtract from all I've suggested.
As the great philosopher Forest Gump said, "That's all I got to say about that, I think I'll go for a run."
PAUL