Newb with Basic Questions

[Believer]

Forgive me if I show ignorance but this is the place to get smart. I want to build a home in a few years--a timber frame in central Kansas, 2500 sq ft, radiant slab, fair amount of passive solar gain. I want to figure out the radiant heat, at least the general components I'll need. In doing a little reseach on the internet, it looks like one option would to use a high end domestic hot water heater; this I'm reading about at the Radiantec web site. I will need to be able to winterize so I'll need an indirect system.

Am I going in the right direction? Is a water heater the right choice or should I be thinking boiler? Does the solar gain complicate the design or is it just a summing heat source?

 

[in hot water]

Consider a small high efficiency modulating boiler with a DHW tang inside. These combo units will run the floor heat and supply about 3 gpm of endless hot water.

There are many brands out these days. Triangle Tuber Prestige is a favorite, Baxi, Laars, Lochinvar are some of the boiler brands. Most of the tankless brands offer them also. Navian, Rinnai, Takagi.

I would advise against a system the uses the DHW as the radiant floor heat, keep the heating fluid separate from the potable water.

Here is a download that shows a number of ways to pipe solar in with DHW and radiant.


www.caleffi.us/en_US/caleffi/Details/Magazines/pdf/idronics_6_us.pdf

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[rkusek]

I would also be cautious about the Radiantec setups because of the way they use potable water for heating.

 

[Como]

Should be able to design the Domestic water system to drain down pretty easy.

The radiant slab could be a bit trickier but you can use a Glycol mix, hence the need to keep the systems separate.

 

[ISeeDeadBTUs]

I do not believe a DHW heater will sufficiently heat 2500[] slab. Our first year we had trouble heating a slab half that size when it got good and cold. To this day I am amazed at the load CC is. And yup, it's insulated.