Radiant In Floor Heat In Depth

[muddy]

As my new shop will be started real soon.......I'd really like any in depth information from experience or just knowledge of the in floor radiant heat. I'm looking at Radiant Floors for my package but would be open still for any recommendations........also water heater with antifreeze versus using a boiler.
My shop will be 36x48 for main footprint with 14 foot walls....floor 4 inches thick.
I know heating has been discussed but I'm new to site within the last few days and am short on time before decision is made on which radiant floor system to go with.........thanks in advance....and I love this site........Keith

 

[TOMWELDS]

My employee is a pro with radiant heat, unfortunatly he's in LONDON of all places. I wire the systems for him (he also does plumbing work). Ive hooked up 'Viessman' systems, but you dont have to use there boiler. Ive never seen one with a hot water heater. There's a balancing manifold so you can balance all the loops. There's not just one loop, you'll run several and have to balance the flow so the heat is evenly distributed. Shop around for prices on the tubing as its expensive. The tubing is pressurized with air and monitored with a gauge, as the concrete is poured. This will show any leaks from the pouring process. The pressure will go up a little as the concrete gets hot curing.

 

[cork]

I recently built a 32x42 block building with 12' walls. I went with a radiant heat system from
radiantec (www.radiantec.com) They were very helpful in explaining what i needed and how to install. I do not yet have a heat source for the floor. They recommend a water heater.

 

[muddy]

I appreciate the input.......look forward to any other thoughts .......... Keith

 

[Mowog73]

For a garage all you need is a hotwater (probably 60 gal), one thermostat controlled control valve, and infloor tubing. A pump isn't required, natural thermosyphoning would work, but would perform better with a small pump. A plumbing supply wholesaler knowledgable in radiant infloor heating systems should be able to design the system for you.

To make the system work well, you'll need to insulate the slab from the surroundings by laying down 1.5" of styrofoam-type insulation under the concrete slab; you don't want to heat the earth, just the slab.

 

[TimB]

I had a house with radiant heat - it used a small "boiler" which was really a furnace with an air to liquid heat exchanger instead of air to air. It also had a 3 gallon expansion chamber and 2 circulating pumps. It was very efficient. I think the boiler is more efficient than the water heater types because you are not keeping a large volume hot all the time, but initial cost is higher.

The only real complaint was when you have a rapid weather change - the floor takes a while to heat up or cool down. This might require supplemental heat for the quick cold snap, and open windows/doors for the quick warming spell.

If you are planning a lift or other large bolt down equipment - make sure you know there are no tubes in the area you will be drilling for anchors. Also step up to 6" thick in the area you might install a lift - 5" minimum is required for a 2 post lift (10,000 lb rated anyway).

 

[Mowog73]

For the area of a garage, 2-1/2 car is what I had, the hotwater tanks worked very well. For a house, yes a boiler is the way to go, unless you are incorporating solar along with the hot water tank(s). My garage was insulated to R-30 in the walls and I never had a problem with the temperature in the garage, even when the outside temperature changed rapidly, but that is a valid point to make. I had installed a couple electric baseboard heaters, but they never got used. A benefit of the hot water tank is that the tank does give off heat to the room as well, and the initial $ investment is lower. If you find that the hot water tank does not provide enough heat, a second can be added, or change to a boiler with little wasted cash.

 

[number3]

http://www.doityourselfradiant.com/index.htm

Good, Bad or Ugly?

 

[messup]

A tip for you is if you are using a non metal tubing (ex pvc) in the floor lay pieces of coat hangar or welding rod every few feet that way you can always find your lines if you are to later need to drill in to the floor to mount a lift or other equipment. just use a metal dector and draw out a grid before you pour and you should never have to worry about a line puncture.

 

[Satatic]

I notice you said 4" thick... are you sure you want to do that?

 

[MCraven210]

I just got my system up and running. I used Radiantec.com and also used a Polaris water heater. All I can say is it is great and they were very helpful. My contact at Radiantec was Don Vance. You can read their web sit and get all of the info you need and if you have questions they will explain it further. Mike

 

[cork]

Is the Polaris much more efficient than other water heaters ? It sure is expensive.

 

[Stuart in MN]

If you're in a hurry to get this figured out so you can start construction, concentrate on preparing the slab and designing the tubing installation - after you get the tubing laid out and the concrete poured, then you can worry about what kind of heating and circulation system to use later.

A good resource for radiant floor heating info is here:
http://www.radiantdesigninstitute.com/

 

[MCraven210]

I have the Polaris 34 gallon 100,000 btu natual gas. It is heating my 2000 sq.ft. garage. The tag says 96.7% efficent. It will heat the water about 4 times faster that a normal water heater it is very impressive but expensive. I hope the high efficency will make the cost worth it.

 

[86swb]

I have the Polaris 34 gallon 100,000 btu natual gas. It is heating my 2000 sq.ft. garage. The tag says 96.7% efficent. It will heat the water about 4 times faster that a normal water heater it is very impressive but expensive. I hope the high efficency will make the cost worth it.

Who sells the Polaris water heaters?

 

[z28toz06]

The smallest polaris is a 100,000 BTU unit, its for very big floors. I believe you need at least 50,000 btu unit to do the in floor heating. You need several zones as if you have it on one it will be cold at the other end somewhere around half way maybe, depending on the size of the room and length of the tubing. You can use 1/2" pex or 7/8" which is more efficient. You need to keep each loop to around 250 feet or so. Set up several loops on one zone so it maintains the same temperature. I was worried about the drilling thing also but other than a lift I dont think Ill be drilling in to my floor at all. Most code calls for 4" minimum concrete, so if I do Ill make sure I dont drill all the way through.

Make sure you get a hot water heater that has a closed ignition system, if you are storing flamables in the garage.

The hot water heater he recommended is a model A.O. Smith BFC-50. (L.P.) propane fired. I would also recommend a TEKMAR hot water reset controller that will vary you water temperature based on the outdoor air temperature. ex. If it is 0 degrees out, you water heater puts out 140 degree water. If it is 40 degrees out, your water heater puts out 110 degree water for futher energy savings.

Im just learning about it myself, and a friend has been helping me.

 

[MCraven210]

I purchased my Polaris from Radiantec the shiping was included in the cost and I think that it came direct from the factory.

 

[peter_]

Just wondering how did the project go? Was it postponed or completed?

I would always suggest to use a local expert, who knows best what works well in your state. It is especially important to know local codes, weather conditions, local supplies. Although, internet prices are more competitive than at local supplies.

For example, if you decide to get 1/2" - 500 ft Pex Tubing with oxygen barrier online it can cost you around $140 - http://www.pexuniverse.com/store/category/barrier-pex-tubing-12
if you go to local supply it is around $220-260 for the same pex tubing with oxygen barrier.

At the same time, even if you shop online prices may vary on brands. For example, 5"x12" 50-plate heat exchanger for radiant floor heating you can get for around $1,200 for FlatPlate brand http://www.pexsupply.com/FlatPlate-...hread-60-GPM-Heat-Exchanger-5-x-12-5791000-p; or you can get Brazetek brand for $400 http://www.brazetek.com/products/ca...ess-steel-copper-brazed-plate-heat-exchangers

So, again I would recommend getting a local experienced contractor. Fixing mistakes is usually more costly than paying expert to get radiant floor heating project done for the first time.