Quote:
Originally Posted by AC_Hacker
Do you actually think that a traditional hydronic heating setup (which is designed for 140F - 160F feed temps) will provide the required heat transfer?
This is exactly the place where traditional thinking fails in low temperature heating installations like solar, geothermal, etc.
Very few hydronic installations (Daox excepted) have built-in efficiency to take advantage of feed temps on the 110 range (and lower).
Vlad's house works with 12" spacing & aluminum heat spreaders because he heats all the floor area, has rigorously reduced infiltration, and put in very good insulation from the start. With three floor levels, his floor area/house volume ratio is fairly high, which favors radiation. Also because his house is large and vaguely tends toward a cubic form, his external area/house volume ratio is relatively low so his house favors lower skin losses.
Did I mention his floor is topped with porcelain tiles, which has a very high U-value?
Lastly, he lives in the Vancouver Canada area and the HDD are not as high as they are in a place like Minneapolis, MN.
Vlad reported feed temps in the 112 range when the weather got really awful.
Of course, awful in Vancouver could be a relief in a Minneapolis winter, or a Colorado winter at high elevation.
-AC
|
When I was talking traditional, I was actually thinking of in-floor as opposed to radiator against the wall. Traditional being hydronic as opposed to a heat pump setup. Even Daox has loop overkill for his serious window and high levels of insulation with 110f input temps. A hydronic in-floor loop, air sealing of 3ACH or less, insulation better than code(I prefer double of the older R20/R13+5 code and a step better than the 2012 IECC 20+5 or 13+10 values for climate 6+), and double pane or better windows with good seals should be fine with 110f input temps and a reasonable water flow rate.
"Lastly, he lives in the Vancouver Canada area and the HDD are not as high as they are in a place like Minneapolis, MN."
Values are in SI (C, not F).
Minneapolis, MN
http://cms.ashrae.biz/weatherdata/STATIONS/726580_s.pdf
Vancouver, BC
http://cms.ashrae.biz/weatherdata/STATIONS/718920_s.pdf
You weren't kidding, Vancouver seems nice.