hydroair to radiant upgrade

sws2_2

Have a house with 2-zone hydro-air and CI oil-fired boiler with indirect. 1st floor is about 1500 sq. ft with 650 of that having a cathedral ceiling height of 20' open to 2nd floor living space. Heat is adequate but would like the comfort of radiant, particularly in the high ceiling area. Will have contractors in for design/prices but have a few questions to be a little more educated:

1- Area with 20' ceiling has a full 2" thick wood subloor from old construction (not finished yet, probably will be laminate). Too thick for efficient staple-up? Any products thinner than warmboard for a top install? Balance of 1st floor is standard 3/4 ply so probably will go with an under floor install. Have insulated crawlspace. 2nd floor will remain hydro only.

2- Would like to use Hydro-air as a second stage of heating. Which is preferred method of low radiant temps while having capability of 180 for hydro and indirect. What about aother indirect set at a lower temp for radiant? Dont want to mix radiant with existing domestic.

Thanks, will be an interesting project.

sws2_2

?????????

No oinions?? I Guess I'll put in electric!

jeff_51

you can go primary scondary loop

to get you the temp diff you want for radiant and the hydroair, or go with an exchanger, which is really the same principle. Not sure what the insulation value of 2 inch wood is, not much I imagine. Radiant floor in the cathedral would certainly be the way to go. Hang on awhile longer, you will get at least a half dozen answers this weekend. We all get a bit zoned out by friday. I'll check my heat calcs and see if I can get a heat loss factor for that much wood

jeff_51

only guessing

I would guess the insulation factor would be about .15, maybe to .2 Not alot in anycase

DaveGateway

If you dont want to add

an inch to the floor, electric matting might be your answer. Sounds like you only need to warm the floor if you're keeping the hydro air anyway. Take a look at
www.warmzone.com

sws2_2

I was only kidding with electric (i'm an electrician). Electric is about 13 cents a kw, it would kill us. I'm keeping hydro because (a) it is only 2 years old and (b)It is a seasonal house in which I drop temp to about 50 when unoccupied. I thought I would put in a 2-stage stat with radiant as primary and hydro as secondary. any thoughts?

sws2_2

radiant floor

The floor, when finished would be 3/4 sub-sub floor with an 1-1/4 sub-floor (both existing) topped with a Laminate or hardwood. Total would be 2-1/4 - 2-1/2" thick. Would an above floor method be more efficient ? The wood would not really be considered a "thermal mass", correct? What are advantages / disadvantages to a heat exchanger vs. a primary / secondary loop system? Thank you.