Radiant heat system recommendation

Bob_117

Hello,

I’m about to build a building in Minot, ND that will be our temporary home (a few years?) while we build our main home. It will be a 30X40 slab on grade 2X4 wall construction with living area, bedroom, kitchen, bath and laundry facilities.

I would like to put a radiant heating system in, but have a wood stove be my primary source of heat. The radiant system would not be overtasked.

I’ve been doing some searching online, but am somewhat confused by all the options. I need to save $$ for the main home, so am looking to keep costs to a minimum. For a 1200 square foot building with a wood stove, what would be the most cost effective radiant heat system to use?

Thanks!
Bob

Charlie from wmass

Please look for a professionel as I have seen one too many online purchases cost twice as much to fix as a good system would have cost to install. Viega makes what we use for all our installations. matched with a good boiler it will save a lot in the long run. what is your fuel choice? Also if cost is an issue why not install perimeter baseboard for the temp house? If installed well with a low temp design ( more fotage of heat emmiter than is commonly used) it can be quite efficent. Also 2 by 6 walls may be worth the added cost.

Bob_117

My fuel choice will likely be propane...been reading that electric typically isn't a good choice with radiant heat. Wife likes the idea of warm feet, so not sure baseboard would provide that. Trying to find the balance between comfort and cost, considering the building is going to be a garage/workshop/guest quarters for the long haul. Looking for the least expensive good system, if that makes sense.

Andrew Hagen_4

Low Load Radiant

First of all, I would sheath the building with foil faced polyisocyanurate foam for a 2x4 exterior wall. You need a thermal break to provide a good R-value in a thin wall. Urethane spray foam (Corbond) insulation is a good choice also.

Second, I would insulate beneath the slab with 2" of extruded polystyrene foam or use the Crete-Heat or similar product.

Third, I would install 1/2" tubing on 12" centers and connect the loops to a Laing EPR electric heater. If you are using the wood stove as the main heat source, it will not make financial sense to go to the expense of installing a gas-burning appliance. Unless something has changed lately, MDU has some good rates for electric heat.

I have family in the Minot and Williston areas, and was just there over the Thanksgiving holiday.

Bob_117

Andrew,

That was VALUABLE info...thanks! Can I get a steer on a Laing dealer? Can't seem to find any pricing on line. I think their product you recommended may be exactly what I'm looking for.

Thanks,
Bob

Andrew Hagen_2

Laing

Laing's US website They have a list of representatives under the "Contact Info" link. Unfortunately they do not have information on the EPR heaters on their US website, but they are very available.

Caleffi's idronics journals are very informative also. Issue 4 may be of particular interest for you.

I should mention that 1/2" tubing loops should be no longer than 250 to 300 feet and should be as close to equal length to each other as possible. 12" would be a maximum spacing. 9" spacing may be desirable. I would definitely protect the system with propylene glycol. Dowfrost is a great product. Make sure to insulate the edge of the slab too.

Mark Custis

The nice thing about

radiant floors is the water does not care how it gets warm. The lower temps make it ideal for solar assist.

On a floor like you describe, here in Cleveland, we would use 6" OC around the edges for a few feet then go to 9" OC for the rest. We tend to put more tubing in to allow for more flow and lower temps.

Don't forget the mixing valve, think HOT FEET, with a wood fired boiler.