Replies

1. 
   Piffin | Dec 31, 2003 02:52am | #1

   You put it under the slab instead of in it?

   Did you place any foam insulation under it?

   18" spacing and up to 250' long is normal.

   What is your climate?

   Is the sunroom insulated or just a box full of windows?

   .

   Excellence is its own reward!

1. 
   tedtemple | Dec 31, 2003 06:05am | #3

   Piffin and Mongo, Tubing is in slab, about center. "Insulation" is a reflective about 1/4 inch waffle foam affair that they sold me where I bought the pex. Roof is insulated the rest is mostly glass (Anderson double pane). A little east of San Francisco. Concrete is probably about 4000 psi by now, poured a couple of years ago- you know how slow working on your own house goes even with the wife wondering if it will ever get done. If my set up won't work I'll just abandon it, just a little labor and a few bucks in materials lost, and go with electric baseboard, but I still wonder about pumping some hot water thru and seeing how it feels. Thanks for your help, ted

1. 
   Mongo | Jan 01, 2004 03:03am | #6

   The insulation you have is virtually worthless. 2" of a high-density foam board would have been better.

   Depending how far east of SF you are may show if the slab can put out sufficient BTUs upward. Eventually you'll reach a "kind of" saturation in terms of heat going down.

   Still, you may as well fire it up and give it a shot.

   Bravo on the bravado to put the system in. A little more planning and a few dollars spent on proper insulation instead of the waffle, though, and you'd be in warm-footed heaven.

   Again, give it a chance, see how it works.

2. 
   Mongo | Dec 31, 2003 05:19am | #2

   If the slab is not green, have at it.

   Having the tubing directly on the insulation at the bottom of the slab is indeed a valid method of installation, though I hope the edge of the slab is insulated as well.

   Six inches of 'crete is a lot of mass, it'll require around 12.5 BTUH/ft2 to raise the temp of it 1 degree. Thus, your ramp-up time to get the slab to temp will take several hours. In operation you'll have long response times, too.

   Good luck, and I hope it works well for you.

1. 
   greggo | Jan 01, 2004 12:49am | #4

   Mongo I sent you an e-mail, are you not interested in the job? 

   Edited 12/31/2003 4:50:10 PM ET by GREGGO10/2 10/3

1. 
   Mongo | Jan 01, 2004 02:58am | #5

   Just found it. It got kicked out and was in a "hold" folder. I'll reply later.

1. 
   greggo | Jan 01, 2004 03:49am | #7

   ok thanks