I want to install radiant floor heat in new construction. Some floors will be concrete and some will be wood. My dilemna is that there are so many options out there for radiant floor heat that I am confused. Feedback on a good do-it-yourself system?
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Do you want electric or water heat? Some floors will be concrete and some will be wood. Are you referring to the sub-floor or the finished floor? I recently did an electric heating cable sandwiched between a concrete slab and floor tile. Wasn't too bad.
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
I can't speak for the wood, only concrete. My system is very basic, but I love it. As I was finishing my basement, I tied 3/4" pb tubing to the reinforcing mesh. PB has had some problems, and from what I understand, PEX is a good choice for embeding in the concrete. I hooked up a line voltage thermostat to a Grundfos hot water circulation pump and a 40 gal gas hot water heater. I don't know about the overall efficiency, and there are a lot more sophisticated ways of doing it, but I am well pleased with the warm concrete floor. My bare feet would recommend it even for concrete floors in Florida.
Wirsbo and most other manufactrurers of the tubing have good installation/design guides. Yes, PEX is superior but between brands, I'd go with one that is supported locally with parts, loaner crimp tools, etc.
If you are looking for a contractor good at RFH, ask for references and only give weight to those you talk to who have been through a full year of heating and cooling seasons.
If you plan to design and install DIY, then you have a lot of reading to do. And posting specific questions here. You should understand high-mass versus low-mass systems, why lag time is always a bad thing, and your choices of heat source.
I am finally back online....There are no radiant floor contractors in my area of Wyoming, so if I want to install it I will have to do it myself. I know I have a lot of information to digest but know it is somehting that can be tackled. It isn't rocket science, is it? I am planning for inslab in basement, under the subfloor in the main floor (would metal joists help conduct the heat?), and ice melt on the driveway and entry sidewalk. Would like to preheat the water with solar, then use natural gas for the backup.
We installed radiant floor heat in our existing wood floor and I've been on quite a few jobs were its been done in new construction and existing construction.
The only brand that I can recommend is Wirsbo--back when we did ours--7 years ago, they were the only company with a 30 year track record. They sell one piece extruded poly tubing--it is the hard whitish stuff that you may have come across. I know others are making it as well, but haven't followed it over the last few years. I leave that to the heating guys. For awhile contractors in our area and DIYSers were using a product I believe the name was Heatway. It installed very easily--it resembled car heater hose, was very flexible and you stapled it to the underside of the sub floor with a special gun. All this made for a very easily installation. However, I 've heard that just like our car heater hose this stuff fails in time and allows air to enter the system which is death to your other components--and furnace. The Wirsbo, is a bit tougher to install because the tubing is fairly rigid. Our installation is in the joist bays and then attached to the underside of the sub floor with alum. heat shields, that are screwed to the sub floor. My heating guy made his own--but Wirsbo tries to get you to buy theirs. This way the tubing contacts the floor for convection and the metal spreads the head, in addition we insulated under the radiant in every joist bay with standard bats. We love our system, with regular temps of 0 degrees and even days of -20 F we remain a comfortable 68 inside. Our Weil McLain oil burner also runs some traditional baseboard heat on our second floor, and heats our domestic hot water with a Phase Three watermaker. By the way our finished floors under the radiant are a mix of carpet, wood, and tile. A qualified experienced radiant guy can give you allthe details. Also, there is likely a post somewhere that addresses wood floors over radiant and how best to install.
Well, this is sort of strange...I log on to ask a similar question regarding RH and here you are! From speaking with some green friends in the biz it seems that concrete is easier, lets say more transferrable in regards to the heating. In new const. you have some more options such as sandwiching tubes in the sub flooring...but I am considering the RH for existing wood flooring which comes with recommendations for insulating below the tubes and creating concave reflective baffles to shield against loss below to an unheated space.
You have deficiencies in that this system will lag similar to a cast iron rad system...but there are new sensors that keep a queue of info amassed about the ratios occuring over time between ambient and outside temp, humid, etc...and 'smartly' decides upon the heating scenarios. The bottom line is that it's a high initial cost...get it right...hire someone with some solid experience for advice and reep the benefits in low heating costs down the line...
do you want to know what gas cost me today????
Eman
Kaz, go to heatinghelp.com and order Dan Hollohans book 'Radiant Floor Heating for The Non-Engineer installer' also get John Singenthalers book - it's the radient floor heating system bible; check out Johns articles at pmmag.com. The two mentioned books gave me the confidence to tackle the radiant floor heating for my home - though I did have the tubing layout professionally designed. Also check out Kitec radiant floor tubing at http://www.kitec.com, it's the Mercedes Benze of radiant floor tubing. If your going to use gas, consider using a modulating condensing boiler with outdoor reset - Viessmann makes the best one on the market, the VitoDen.
Make sure to get a professional heat loss done for your new home before you start anything.
Good Luck
I've had good luck ordering prepackaged systems. I've been using In Hot Water, out of Eden UT, but there are at least a few other outfits around that do the same thing. They also rent some of the specialized tools that make the job pretty easy. Wirsbo tubing, Munchkin boilers seem to be their standard product line.
Kaz-
I would chose products that imbed the pex into aluminum strips if I had a choice. It gives much better lag time (turn up the thermostate and the room gets warmer) than imbeding the pex in concrete.
If you're up north, think about pex in driveway for snow-melt.
You get out of life what you put into it......minus taxes.
Marv
You and kaz are talking about snow-melt radiant driveways and I thought I'd add a few thoughts here.
They are neccesary, IMO, if you are a hospital, rest home, or upper end hotel in snow country. They are very nice if you are a commercial property or a rich home owner.
Or, if you are middle-class, a snow-melt sidewalk or porch can be a nice luxury and safety item.
Radiant driveways, however, are expenisive to install and operate for the average person. Not only are you buying a bunch of tubing (about one linear foot per square foot) but, much more so than in the house, you are buying a bigger heat source (boiler, multiply HWHs, tankless, etc). That is because if you have a small heat source, you can't keep up with heat losses and get the concrete warm. The more BTU/hour you have, the less total BTUs you will use (and, obviously, it will take less time).
There are some interesting design issues, like: Where does the melt water go? You may melt snow, but create a skating rink elsewhere. Remember, it is, by definition, below freezing outside, so it won't just run down the gutter. Heat-traced (with RFH) gutters and drywells are a possible option. Thinking that though, and you realize slope and drainage are very important to get right. A spot 1/2" low will hold a ton of snowmelt and require it to be evaporated by the radiant system - and it takes 7 times the energy to evaporate as it does to melt!
Normal slabs are expected to crack and control joints are often put in. But you don't want to stress the tubing. I'd keep it along the steel so it can get torqued, and bent too much.
Do you plow then snow-melt the traces away? Or snow-melt the whole 12" of new snow? Makes a big difference in heat demand.
Which anti-freeze? Ethylene Gycol - cheap and toxic. Or Propylene gycol - more expensive but safer for kids and pets.
Control scheme - a wind-up timer control? Sensors in the slab to get to 40-45F and then shut off? Controllable from inside the house or do you have to go out to the garage?
I love our snow-melt sidewalk - free and clear of snow and ice. But I shovel it first and the heat demand was small enough that the HWH for the garage RFH could handle it. So the only expense was 250 feet of tubing, an extra pump and a heat-exchanger.David Thomas Overlooking Cook Inlet in Kenai, Alaska