radiant heat in slab questions
I’m in zone 6, and building a garage (32×44′). There are not many people in my area who know much about radiant heat, so I’m kind of on my own. I plan on 3.5″ of EPS on top of 2″ gravel, then poly, then rebar ( with blocks under to suspend bar and tubing into center of slab height), with 1/2 pex zip tied to the re-bar. I haven’t decided on what source for heat yet. My questions are:
1) what type(s) of pex are acceptable/preferred for in slab? Everyone swears their own product is the best.
2) I figured on using 1/2″ spaced 12″ apart. Does this seem like a good plan (or should I change size and spacing)?
3) Do I need to install anything else in the slab, such as thermostats, etc.? I see max lengths from 200-300′ for 1/2″, and I’m not sure what is recommended. Is there a minimum length to use for pressure, turbulence, inefficiency?
4) Are there any precautions to take to account for the slab cracking at some point (other than saw cutting a bit below the surface?
5) for this size, in this zone, is a high efficiency water heater adequate and/or recommended? Tank or tank-less?
I appreciate any guidance you can offer. Thanks in advance.
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