Radiant Heat, Where To Start??

[ktm rider]

I have an indoor coal boiler in my detahced garage and this is currently heating my home with a heat exchanger going into my forced air syem. it is really a very simple system.
My pipes run into my basement and acrossed the basement ceiling into the heat exchanger. The ceiling in my basement is NOT finished and i was thinking that I could possibly use the hot water that is returning to the boiler and run some pex between each floor joist and using a tempering valve to control the heat and possibly heat up the first floor floor. Which by the way, is a hardwood floor, if that matters.
What would be the easiest ( and cheapest ) way to take advantage of the heat in the return line? Is my plan even "Do-able" without spending a ton of money???

 

[ghitch75]

get 5/8" pex pipe and loop it between each floor joist then jump under the next joist and so on.....keep loops at 300' or smaller...then insulate each joist space....done over 20 systems like that...as far as using mixing valves....i use plate exchangers and a pump to make it it's own system...keeping the nasty boiler water out of it...had pic's of the jobs...but lost my harddrive....my partner has them i'll get them and post

 

[ktm rider]

get 5/8" pex pipe and loop it between each floor joist then jump under the next joist and so on.....keep loops at 300' or smaller...then insulate each joist space....done over 20 systems like that...as far as using mixing valves....i use plate exchangers and a pump to make it it's own system...keeping the nasty boiler water out of it...had pic's of the jobs...but lost my harddrive....my partner has them i'll get them and post

Pics would be great. thanks.

 

[Valkyrie Rider]

What is the temp of the return water? A typical radiant system needs about 100-110 degree water. If it's higher then that, you will need to temper it down.

A strap-on thermometer will tell you the temps if you don't know them. When installing radiant systems, we always use on on the supply pipe to check temps.

The piping you would normally use would be 1/2" pex WITH A OXYGEN BARRIER. If you used regular pex for water lines, you will have problems with air in the system. The proper piping NEEDS to be used.

After the loops are made in the joist bays, you need to insulate under them. There are different ways/systems for installing the pipe in the bays. Each company has their own system it seems.

Last time my I bought pipe through my company was between .50 and .60 cents a foot.

As was mentioned before, you need to keep your runs a reasonable length.

You will also need a manifold set-up for multiple loops that you run. You need both a supply and return manifold.

Hope that helps!

 

[ktm250rider]

search for diy radiant companys. Theres a ton out there with all the components and sample systems. Its not as hard as most plumbers want you to believe.

 

[ktm rider]

search for diy radiant companys. Theres a ton out there with all the components and sample systems. Its not as hard as most plumbers want you to believe.

Fellow KTM guy.

You are right, they always want you believe everything is " Rocket Surgery" (as my daughter calls) That way they can stick it to ya and charge you a fortune for doing something that you coauld have easily done yourself...

BTW, I sold the KTM and bought a new YZ. maybe I will change my screen name now to YZ rider..

 

[zsteinmetz]

Im going through about the same predicament now only I have a owb i wanna use. Talkin to some guys they say just use the boiler water at 180 degrees and not to make it its own system. Cheaper and probably easier to do yourself if your a do it yourself er like me. Im gonna T off my supply line coming from my boiler then put in a pump then split off into three 250' loops and then back to the return. Put the pump on a line stat and use 1/2 in pex two in each joist.

 

[trax]

Im going through about the same predicament now only I have a owb i wanna use. Talkin to some guys they say just use the boiler water at 180 degrees and not to make it its own system. Cheaper and probably easier to do yourself if your a do it yourself er like me. Im gonna T off my supply line coming from my boiler then put in a pump then split off into three 250' loops and then back to the return. Put the pump on a line stat and use 1/2 in pex two in each joist.

You do not want to run 180 degree water though a radiant floor system no matter what your freinds tell you. You don't need to make it an isolated system you can control the water temp with a 3 way valve and pump.

 

[Valkyrie Rider]

I never said it has to be complicated! I mixing valve isn't that much money and you can MAKE your manfolds out of just a little bit of pipe and some Ts... you could even use black steel Ts and black pipe nipples. It doesn't have to be complicated OR expensive.

My boss didn't even buy Ts for his radiant manifold.... he hole sawed a piece of 1" copper and brazed some 1/2 copper stubs onto it, then sweated some pex to copper valves on that to throttle it.