Steve29
New Member
We are building a two-story home at 4500' elevation in Northern AZ (zone 4 to 5). We'll have a ducted, 6-ton geothermal F/A system, but would like to add comfort to three of the downstairs, slab-on-grade rooms by adding a simple, low-cost radiant system (the footers will be poured in a week or so). The two important rooms are about 400 and 200 SF, and the less-often used room for the radiant system is 200 SF (we would do a fourth area, about 400 SF, if the system would remain simple). I'm thinking something like three to four separate runs of PEX, and maybe just ball valves to regulate the flow from a water heater (but plan ahead for possible thermostats?). If so, what PEX specs (diameter, etc), what type and specs for the water heating unit, etc? (i assume a gas heater is the way to go - current winter rate is around $1.17/therm.) Or is there a better way to do it? The key thing is to keep it low-cost and simple, since it's just adding a layer of comfort to complement the 6-ton F/A system (which could be a tad undersized if it gets really cold). As for comfort in the two infrequently-used guest bathrooms downstairs, I'm thinking an electric mat in each. Thanks for your help!