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Installing radiant heat in garage slab

bruce_21
bruce_21 Member Posts: 237
A gas, oil or electric hwh should be elevated at least 18 inches above the floor to prevent gasoline vapors from being ignited by the burner or switch contact arcs. There are new now mandatory designs that limit this flashover, but keeping it up is always a good idea.

Comments

  • RDB
    RDB Member Posts: 7
    Radiant heat in garage slab

    I'm about to start construction on a 32'x26' garage. I'd like to have radiant heat in the slab. Keep it 45 degrees or so in winter, put it up to 65 for work projects.Have looked at Radiantec's website there Closed Loop system looks pretty good for that application. Have seen some negative posts on their Open Loop, what do you think of their Closed Loop system? I live in NY. Can I put a gas fired hot water heater in the garage if it's enclosed in a fireproof enclosure? or does it have to be located outside in some type of enclosure? I'm new to this so any suggestions would be very helpfull. Thanks RDB
  • RDB
    RDB Member Posts: 7
    Radiant heat in garage slab

    I'm about to start construction on a 32'x26' garage. I'd like to have radiant heat in the slab. Keep it 45 degrees or so in winter, put it up to 65 for work projects.Have looked at Radiantec's website there Closed Loop system looks pretty good for that application. Have seen some negative posts on their Open Loop, what do you think of their Closed Loop system? I live in NY. Can I put a gas fired hot water heater in the garage if it's enclosed in a fireproof enclosure? or does it have to be located outside in some type of enclosure? I'm new to this so any suggestions would be very helpfull. Thanks RDB
  • Ron Gillen_3
    Ron Gillen_3 Member Posts: 5
    Another option

    With radiant floors, you need to decide today if you want it warm tomorrow as they are slow to respond. If you don't plan on keeping it warm all the time, my preference is to insulate the slab to reduce heat loss to the ground and install a radiant tube heater which will warm up the garage in about an hour and is almost as efficient. They are also a much smaller investment. IMHO
  • I'd agree,

    Keeping it at 45* and then wanting to crank it to 65* periodically will not work that well. The slab will take way too long to react and bring the space up to temp. A radiant tube heater, as mentioned, might be a better choice for your application. Unless you lose the setback idea that is. If you just maintain 65* or maybe just 60* all the time with the slab AND the garage is well insulated you really won't spend a whole lot on fuel. You'd probably end up spending more $ trying to set it back and then bring it back up to tell you the truth.
  • RDB
    RDB Member Posts: 7
    Radiant heat in a slab

    What is radiant tube heating? Is it gas fired or electric? How does it work, and is it effecient in warming large spaces? Just so I understand: This is not hot water running thru a series of tubes, correct?
  • Ron Gillen_3
    Ron Gillen_3 Member Posts: 5
    Radiant Tube Heaters

    They are a sealed combustion, suspended heater used in place of a unit heater but with radiant qualities (efficiency). When they are on, you bask in the warmth like the sun on your face. My garage is the same size as yours and when it's set to keep the dog from freezing it seldom fires. There are many manufacturers but mine is SuperiorRadiant. http://www.superiorradiant.com/page.asp?page_id=25
  • RDB
    RDB Member Posts: 7
    Tube Heaters

    Thanks very much for that info on radiant tube heaters. So they are gas fired? They heat the objects in a room, but not the air? Do I have that right? RDB
  • Ron Gillen_3
    Ron Gillen_3 Member Posts: 5
    Gas

    They are gas fired and heat from above in the same way radiant floors heat from below. If you go to Superior's site and look around they have lots of information how they work, how to size, etc.
  • Andrew Hagen_2
    Andrew Hagen_2 Member Posts: 236
    Radiant

    My only concern about overhead radiant heaters for a garage/shop is that if you are beneath a vehicle you do not feel the effects of the heater directly, particularly if the vehicle is not warm. It depends on how you use your garage.

    I would put tube in the slab as the base heating system and install a unit heater to pick the temperature when you are working.
  • Randy_22
    Randy_22 Member Posts: 9
    radiant slab

    We operate in Northern Wisconsin with temps down to -20F occasionally. In 2004 we did an unattached garage 24 x 40 x 10 that had 6" sidewalls and attic insulation at 12". The slab had 2" high density foam underneath a slab on raised grade. The homeowner whom I have done work for in the last 25 years was using this as a garage, but had workshop area. His main concern was that if he was to work in it on Sat am, that turning up the heat on Friday pm would work. Actually was if he wanted to work on Sat at 9 am could he turn up at 6 am when he thought about it. We installed 5/8" tubing on 6" centers on the outer 2', 9" centers on the next 2' and finished to the centers with 12" spacing. We had 3 separate loops that all followed the above. Tubing was tied down to 6" x 6" mesh with wire looping. This was per recommendation of local wholesaler engineer. The owner found that at -10F with the garage at +40F he was able to raise the temp to 60F within 4 hours. All this while the mod/con boiler in the home supplied his heating and dhw. Only drawback was having to add Exhaust fan on timer / dehumidistat for excess snow melt from vehicles. Tubing may have been overkill,BUT if we used 24" centers and used end loops for wall coverage like others how do you go back and tell the people " Turn the stat up on Labor Day and off on Memorial Day?"


  • don't tell them anything. give them outdoor reset and tell them to set it and forget it, and let WWSD do its job ;)

    Your method works as long as you don't have an early bird workshopper. If setback is being used, they are only using it periodically anyway (otherwise it makes no sense to set it back) and you're further shrinking that window.

    Might have been ok for that client, but not for everyone.
This discussion has been closed.