Retrofit - Radiant Floor Heating

Just wondering if anyone here has experience with Radiant floor heating systems for older houses.

We've got electric baseboard heating, and while I like the warmth, the electric bills are kind of steep, and the things up against the walls just really are ugly, and limit where you can put furniture, electronics, etc...

So, I was thinking of getting Pex tubing, making aluminum reflectors and putting the system in under the main living portion of our house (in the crawl space). Of course that would include a good dose of insulation under the floor as well.

Seems like one of those jobs that might be really annoying for a few days (weeks?), but after it's done would be well worth it.

Suggestions?

A couple of considerations:
1. How thick is your floor. If you have 3/4 or 1" subfloor with hardwood on top the floor will act as a reasonable insulator. The thicker the floor the hotter you will need to run your water through the pipes.
2. Make sure you put plastic sleeves over the pipe wherever it passes through a hole or touches wood. The pipe will expand and contract and you will hear 'ticking' noises if the pipe is not well sleeved.

Other than that it should work fine. I have a friend who had a new house built and used that basic technique and he is happy other than the ticking noise I mentioned above.

The performance of your system can be quite dependent on the control system you are using. Better systems monitor the outside temp and set the water temperature based on the difference between indoor and outdoor temperature. Simpler systems use a fixed water temperature and control the heat by turning on and off the flow. These systems are more likely to make noise as there will be bigger changes in the size of the pipe.

Greg

I installed radiant floor heating in my new shop a few ago. It is just amazing how well it works. I used a company called radiant floor company. they are geared to the do it yourselfer and were extreamly helpful. They designed my whole system. they have a great web site that is very informative.

http://www.radiantcompany.com/

I bought everything except the copper pipe and a few standard fittings from them but I guess if you check around you could find better pricing, but I thought it was pretty reasonable considering all the help I got from them. My only complaint was that it seemed like I got $25 and $50 dollared to death which made me go over budget a bit.

I have a newer house and I am already looking at this for the first floor. I have spent a fair amount of time researching and the thing that I am still unsure about is if I need to run the alum. plates. The website Larry lists talks about needing them, however I have seen other published studies that show that they really don't work well, are noisy, and expensive. The radiant company sells 7/8" (I think) tubing - this allows longer runs. The pumps that radiantcompany supplies are very small - another company that I was looking at supplies a larger pump that allows longer runs/ more runs on a zone. Due to greater head and flow rate curve.

Then there was the Pex A,Pex B, Pex C, Al Pex etc. oxygen barrier etc. I got different answers each place I looked.

This site had a lot of information - I just don't know what to believe at this time,

http://www.radiantdesigninstitute.com/
http://www.radiantdirect.com/

http://www.radiantdesigninstitute.com/page6.html

The last page is supposed to show a IR picture of the alum plates not working -

I wish you the best of luck . I gave a feeling that I still will be reading and trying to figure this all out by the time you get yours done!:D

- Rob