I'm building a house (all metal) with a concrete slab floor and will be using radiant floor heat. I plan on using pex tubing for the floor heating system. There are a few diffent types and few different types of fittings available. With virtually ZERO experience with pex I'm rather confused about what to buy. I've looked at products at Lowe's and Home Depot. Of course, the reason for buying off of the internet auction is the price.
One type of tubing that is totally new to me is Pex-Al-Pex or Flex-Al-Pex which are virtually the same thing. (a layer of aluminum tubing sandwiched between two layers of pex tubing). There's also Pex A and Pex B. Anyone with knowledge/experience of these products please give me some pointers. I'm not looking for the most expensive thing I can throw my money at. I'm looking for the best I can get at the best price.
The footprint of the house will be 2816 sq. ft. I need a very rough estimate of how many feet of 1/2" tubing I will need to put in the concrete using normal 1' spacing and doubling around the walls. If I have a couple of hundred feet too much that is no problem as I can use it later when I start on the upstairs sleeping lofts. ANY suggestions or advice will be appreciated.
I'll worry about the mixing valves, manifolds, circulating pumps, etc once I get the project above ground. For now I'm just planning zones and bringing the tubing up in a central location.
ALSO... I'm seriously considering an instantaneous propane water heater rather than a water heater set up for a heat source... pros & cons? (sounds stupid to some but it is being recommended by the manufacturer of the heater). This is in Alabama where radiant floor heat is extremely rare and most plumbing and HVAC companies don't know what the heck I'm talking about.