[randen]

nib

I used 1 ft centres for 5/8 ID tube as that was the tech available. 1/2 pex. will be perfect on 1 ft. centres. So for your calculations 1200 Lin ft. and really its quite in-expensive. Are you planning a slab build or a gyp-crete overpower (self level) on subfloor.

Don't over zone, 1 thermostat controlling the slab temp. and 200-250 ft loops.

I've built mine on slab and heated floors are awesome. Some here have eluded to in-floor being expensive but I've ran the numbers for other requests and they are less than duct-work especially if your doing the grunt work.

If I were to do it again I would run two pex systems 1/ for your outside wood or gas fired boiler and the 2/ for solar hot water. This saves the cost of a heat-exchanger and efficiency losses. We have solar hot-water heating the floor and some yrs it supplies 1/2 our heat load. The solar hot water would heat your floor directly AWESOME!!!

Randen