heat source for radiant floor

Plumbingpainter

hot rod, 1 single unit would be great due to space constraints. Got NG. Horz or vert vent possible. It needs to couple with closed panel from Rad Flr Co. Where can I find this unit on line? I appreciate your quick response. Thanks.

Plumbingpainter

heat source for radiant floor

I posted a requst for suggestions on a heat source for DHW & Rad flr on the 29th. Brad & Kevin responded & I thank them. The closed system panel I purchased suggests TK-Jr as heat source for floor. Is this a good product for this system(1 room 320sqft / conc flr / no covering/He2 heat loss 17K). Brad noted BTUH potential of up to 11K. Can this be improved? Kevin suggested Embassy Industries Combi unit. Where do you get them and how much are they? I'm sure I sound like a maniac, but need any help thats out there. Thanks.

hot_rod

are you looking for a combo unit?

a heater that could safely heat domestic hot water and a small radiant zone ot two? The Bradford White combi 2 is a tank style water heater with a coil inside for the radiant.

This keeps the DHW and the radiant water separate. it is not an ultra high efficiency unit, but for the cost it works well in that application.

HTP builds a unit called a Voyager. 90% plus efficiency tank with a coil inside for radiant.

I believe the unit you mentioned is an instantanous water heater. You would need a heat exchanger and a few pumps to make that a safe DHW and radiant heater.

There are other mod con boilers that have DHW ability. It depends on how much you want to spend, venting options, type of fuel, etc.

hot rod

Brad White_184

Improving the 11K Heat output

Ah, worth asking. My limitation of getting only 11K out of a 320 SF floor is a function of floor temperature and output. Generally at about 35 BTU's per SF your floor temperature would be close to 85 degrees, a limit for physiological reasons..

That said (and I think I had alluded to this), some supplemental heating surface is in order. Could be panel radiators, radiant wall or even radiant ceiling...

Plumbingpainter

Best heat source for radiant

Hey guys, I guess my decision is whether to go with combi unit (tank style) or two tankless units. Since I do not hear any feed-back on tankless, can I assume there is not much support for these types of heaters in the professional world? Background: Place is a cabin 800+ sqft with wall furnace in old part. I have gutted and re-insulated. Very short distance from source to floor or fixtures. Thanks again.

hot_rod

An instantaneous water heater

isn't a replacement for a good hydronic boiler or heater. they are good for DHW loads, and incredibly efficient (when they are not firing)

They are designed to instantly heat water from 50- 60 or so to 140 and shut down. That is not how a radiant system runs. to start an on demand heater and run it non stop for hours, maybe days doesn't make sense to me

Here is a peak under the hood of a typical instantaneous heater. A bunch of ribbons of burner firing up through some copper tube and wrapped in thin copper.

Check out www.bradford-white or www.lochinvar.com for the combo units I mentioned.

hot rod