Is there such a thing?
I’m building an ICF (Arxx) house in central GA. Floor is slab on grade. I will be installing ceramic tile in the master bath, kitchen & dining area. I’d like to do something to warm the tile. I’m not necessarily going to depend on this as my primary heat source for these rooms, just want to take the chill off of the tile on those cold winter mornings.
I looked into the electric mats that install under the tile, but that seems to be awfully expensive. Total sq. ft. of tile area is about 250. The electric mat materials alone is around $3000 – $3500. Damn! I could buy a couple pair of nice fuzzy slippers for that money!
Here is my idea. Place 1′ styrofoam under slab, lay 1/2″ pex tubing on top of foam, keeping my loops about 12″ apart. Install a dedicated 40 gallon electric WH with a circulating pump, & rig up some sort of thermostat/timer to control the heat. I’m guessing that the water would only have to be heated to about 90 to 100 degrees.
Anybody done this before? What am I missing? I’m sure there is a lot of science to designing a proper radiant heating system if that is going to be your source of heat for the whole house. With the ICF walls and mild winters that we have, I’m planning on heating mainly with the fireplace. (Anybody use the “Fireplace Xtrordinare”?) If all I want to do is warm the tile, do you think what I am proposing will work? Any ideas on how many hours of the day the WH would be in operation?
Nobody around here does anything like this, so there’s no one locally to ask for help.
Thanks, Dawg
“It’s not denial. I’m just selective about the reality I accept.”
Replies
I don't know of any cheap way to do what you are wanting. I would be leary of any untested design that uses water. Maybe you could create some sort of hot air plenum in a space beneath the tiles?
Actually, using a hwh as a boiler is done all the time here.
Not large areas because of the recovery time and the heat is hard to control evidently when the area gets large. Not in the high end. But there are several builders here who build what they call "starter adobes". Slab on grade, pex and a hwh. Why not?
Well ... if it's a system that they have used with success then it's not untested is it? I haven't used it and no one in my area that I know of has. I suspect that you would have trouble getting that past the inspectors here ... but probably not everywhere.
$3000 for the material! I use ThermoFlex to do btrms. It's easy to install, 1/8 -1/4" thick depending on method of installation. If you are jsut taking the edge off the coldyou could maybe space it 8". Anyway you buy the right length of wire and string it the way you like.
Patrick,
Where can I find more info on ThermoFlex. I did a google search and came up with everything but. Thanks.
"It's not denial. I'm just selective about the reality I accept."
Edited 3/17/2003 11:32:19 AM ET by Dawg
Sorry typo. http://www.thermaflex.com/chromoflex.verwerking.asp. I get this or similar at a dedicated tile supplier. Also there are 2 different thermo system, the simplest/cheapest uses a ambient air thermostat to control the on/off, the better (more sensitive) system uses a sensor affixed to the top of the tile to determine on/off. If you end up with the tile sensor make sure you put the transformer in an accessible location. I had to change one a few months ago that was underneath a built in cabinet, the trans failed 'cause it was resting on the floor, which was heated by the system, so it overheated...duh.
None of my business, but I'm curious.
You're planning ICF with slab. How come you're not doing RIH for the primary heat source for the whole house? Perfect fit with all that mass.
SBPERKI,
Several reasons why I really didn't plan on doing radiant heat for the whole house. (It's not too late, I haven't poured my slab yet).
1. I know very little about it.
2. Here in the South nobody does it.
3. With the mild winters we have, & the ICF walls, I think I can heat my house most of the time with the wood-burning fireplace.
4. I assumed the cost (at least the up-front cost, I have no idea about operating cost) would be considerably higher.
Do you think I would be making a mistake by not doing it?
Thanks, Dawg"It's not denial. I'm just selective about the reality I accept."
I know how hard it is to do something that isn't "done" in your area.....but it's certainly worth checking on.
Around here, where it is common, it's around $1000 more than FA, a no-brainer. Most of that difference is simply the fact that you have to run some minimal duct work for evaporative cooling. I have read some threads here that would indicate that people get gouged in the East....maybe just the NE where it's berry, berry cold.
You could actually DIY the engineering and the laying of the pex with help from one of the mfgs if your local plumbers are that proud of the stuff.....at least you can here. Local codes allow an owner-builder to pull their own plumbing permit.
If you could have constant temps, warm floors and no blowing air for a grand or two, isn't it worth checking out? Once you heat all that mass it would probably stay warm for little $$. The house that you're building has the perfect set-up for it. Weil-McClain has a new/old set-up for a combo unit. Boiler used to heat the domestic HW too. I'm trying that one in a house that I'm starting in April. Was gonna try tankless, but this looks more interesting for the same price.
ShelleyinNM
Be sure you include an expansion tank in your design.
Dawg:
You've got to find a better supplier and product - I use Nuheat tile mat here in Canada and it costs me $7.00 - $8.00 ft2 canadian dollars, which is about $2000.00 CDN$ or $1200 for the space you need to install. It installs beautifully and has great customer support and warranty. Thermostat/control choices vary from $100.00 to $400.00. I would highly recommend this product.
http://www.nuheat.com
Gio
prairieHOUSE Restoration & Devlopment
Try this site.
http://www.radiantpanelassociation.org/i4a/pages/index.cfm?pageid=1
your idea is great. e-mail me all the details and I will design it for you. no charge.