Replies

1. 
   NPitz | Jun 05, 2002 01:47pm | #1

   It certainly is possible, and can be a simple (and relatively cheap) way of providing radiant heat where there isn't a boiler already. As far as resources, JLC had a good article on it a while back, but I don't remember exactly when. The Wirsbo design manual also has good info in it. Piping a hot water heater that is dedicated only to space heating is a lot like piping a boiler. Or find a local supplier or sub that deals a lot with radiant heat.

2. 
   DavidThomas | Jun 06, 2002 12:35am | #2

   It works fine in my own house (space heating through RFH anddomestic hot water from one water heater). And for a kitchen, any water heater will have enough heat output. One thing to check with your inspector:

   Can you use potable water in the loop or must it be isolated in a separate loop (using potable water allows you to use the HWH for domestic hot water without using a heat exchanger). Several HWH manufacturers give instructions to install either way (this can helpful back-up when proposing this to the inspector).

   I'd be tempted to incorporate an instant hot loop with the RFH so you have quick-response hot water at the kitchen sink. As long as you are pumping hot water anyway.

   For your customer who already has a boiler, the use of a tempering (temperature mixing) valve should allow you to run radiant off the existing boiler as an additional zone. You need the tempering valve because RFH needs cooler water than hot water baseboards.

   Post again if you have more questions.

   David Thomas   Overlooking Cook Inlet in Kenai, Alaska