In floor heat questions and help

[Tony's garage]

I have been reading this site for two days and I am more confused now. Iam building a new shop 28x32 with a 16x16 man cave on the back I want to do radiant floor heat I have a rinnai tankless natural gas heater I bought on Craig's list for $150 my question is what else do I need and how do I set it up?
Thanks in advance

 

[yeldogt]

The first thing is to make sure the slab is properly installed for the radiant -- well insulated and isolated and proper tubing placement and length.

Then you will have to download the manual for your heater .. and also find the specifications.

rinnai makes a lot of different products and sizes .. more than likely it is for domestic water and high output .. not the best for radiant.

you will find a lot of information -- but getting the floor correct is the most important -- because you can never go back and change it

 

[sands35]

For $150, that will be perfect.

You will also need some sort of a panel. Either DIY one, or buy one.

This is what I used:

Primary/Secondary Flex Pro Panel

2nd one down:
http://www.hydro-smartwholesale.com/Panels.html

Read the manual on that water heater. It should kick on with demand. Assuming it does, the thermostat actually turns on the water pumps. The water flow them turns on the heater.

You will need to put in the vent per the manual. Some only need PVC, some need rated SS parts. A condensing boiler will need a water drain as well. If you do wood working, then you will also need to plumb in a combustion air supply to the boiler.

Do you want the man-cave to have a different temperature than the rest of the garage? If so, then you will need a two zone panel.

Page 2:

http://www.hydro-smartwholesale.com/Images/HydroSmart170-4PanelBrochure.pdf

DIY will cost less, but then you need to learn how to solder pipes. It can be done with all PEX or sharkbite connections, but then you will probably cost close to a completed panel.

 

[yeldogt]

Sands35: Most of the rinnai units are water heaters -- your link is to panels using modulating boilers or properly sized electric boilers

 

[Tony's garage]

http://www.alpinehomeair.com/viewproduct.cfm?productID=453064304&displaytab=instructions_brochures
This is the the heater it's a rinnai RL75in it came with the vent and the valves, I figure if I couldn't use it to heat the floor I would just use it for hot water. I can solder and do plumbing the only thing I can't do is concrete but the wife gave permission for someone else to build it. I was thinking three zones with 3 rolls of 300 feet pex radiantech gave me a quote for $700 for three rolls and the metering valve I think that is really high. Also I was going to put 2 inch foam under the concrete. Yes Yeldogt that is my concern I can't put the pex in after the fact so now it is a mad rush to learn everything I can as quick as possible and yes I would like the man cave a different temp.