Garage heat.

[Jokester]

Hi friends,

This has been discussed before, but I can't find it using the search function.  I'm preparing to build a new shop and would like the skinny on heating systems.  Concerns are initial costs, ease of installation, usage costs, safety (going to be painting in there), and anything else anyone has to offer.  I figure the best time to ask is now, before the first spade of dirt is turned.

Suggestions?  Oh, it's going to be 24x30.  I have access to electricity and natural gas.

thx.


.bjb

[Bib_Overalls]

The best system would be heating coils in the slab and a gas fired boiler out side.  I have not priced them lately but they are more expensive than forced air.  But the heat is better and over time you will save.  Electric heat is almost always more expensive than gas.

[tom36]

If I was building a new garage, it would  DEFINATLY have the heat in the floor.  Over time the initial cost would be insignificant compared to the  pleasure of working with a warm, dry floor.  I've seen 2 in operation and i'm green with envy.  Tom.. :mrgreen:

[Ohio Blue Tip]

Ya, I think under floor heating is the way to go.  If  and when I build a new shop, I plan on using it.  If you do it yourself, I believe the cost is no higher than a forced air system.  There is much information on the net.  Planning your tubing lay out and insulation under the slab is most important.  Some systems only use a water heater as the boiler.

[Stakebed]

I helped a friend build his farm shop- 50 x75 - with hot water heat in the floor. It is a great way to heat, but does have some drawbacks. If you want to anchor anything to the floor you must plan ahead and document exactly wher the tubing is. On his we got dimensions for a floor hoist mounting pattern and worked the tubes around an area for each leg so we can safely drill the floor.
  Another thing is how will you use the shop. the floor heat can take a couple of days to get up to temp, so it's usually best to leave it on all the time, where a forced air furnace alows you to turn the heat on an hour before you want to start work, and shut it down if you won't be working in there for a few days.
   One thing my friend wishes he had done with his is to run an empty conduit in the slab to slide a temp probe into for the thermostat. He often has his door open several times a day to run machinery in or out and the cold air coming in will trigger the boiler as he has a normal house wall thermostat. He feels this is unneccisarily runing the boiler, where sensing the temp from the slab wouldn't.  When the door has been opened (15 x 25, so its a big hole) you wouldn't know it 10 min later.
  That said it is a great way to heat a shop. He keeps his at 62 degrees and it is comfortable in a t shirt if you are doing anything, can be a little cool if you're just sitting bsing. Another nice thing is the floor wil dry if you bing in something that melt off or wash a car, etc.
    A lot of people around here use water heaters as the heat source for their floors. with a smaller shop this might be an option. With painting you may want to put the heat source in a small seperate shed and run the lines underground into the shop. I've heard of this being done by digging a trench and spraying foam insulation over the lines in the trench before burying them.
  If you have any questions on this I can tell you how we laid his out when we built it, I'm not an expert but his has worked out well and has beenup and running for about 3 years now.

[Bib_Overalls]

There is some good info on using a water heater as a heat source for a radiant slab here http://www.jlconline.com/cgi-bin/jlconline.storefront/416aa8a9001cdbe927177f000001060b/UserTemplate/82?s=416aa8a9001cdbe927177f000001060b&c=ea26d15040a43532d4a9669d18125128&p=1

[couper]

I am installing a forced air heat and cool unit in my shop (32X40). As a regular blue collar work-a-day guy, I personally don't have the time, nor do I want to take the time for either a concrete heated floor or a wood burning stove to heat things up for me. When I unlock the shop door, I want to turn on the thermostat, and go to work. I don't want to wait for a concrete floor to heat up, or mess with the a wood burning stove. I generally have around 3-4 hours a night (but not every night) to 'play' in the shop, so instant heat is my preference. A hot-water heated floor sounds great, but it would not fit my work schedule or habits.
I believe that it all depends on how many hours you plan to be in the shop. Daily? Nightly? Weekends only?
There are 90%plus efficient units out there now that make the most of the input BTU's of the natural gas burned.
lance

[Dusty]

HEAT, HEAT, Man forget the heat...Put in Air conditioning...Keeps down the 95+ degree heat, and keeps the 97% humidity way down to about 50%.  You gotta keep the rust off the machine tools, and keep your wrenches cool enough to pickup.....

[Bib_Overalls]

My shop is 32' x 40' and I have a used propaine forced air heating unit set up.  It works just fine.  I can walk in when it is cold and have heat in ten minutes.  But once my slab gets cold it stays cold.  And it continues to radiate cold into the work space.  So my heater is cycling on and off every couple of minutes and my feet never warm up.  Also uses a lot of propaine.  I would be well ahead to have radiant system that keeps the floor mass warm all the time.

[WZ JUNK]

Hi friends,

This has been discussed before, but I can't find it using the search function.  I'm preparing to build a new shop and would like the skinny on heating systems.  Concerns are initial costs, ease of installation, usage costs, safety (going to be painting in there), and anything else anyone has to offer.  I figure the best time to ask is now, before the first spade of dirt is turned.

Suggestions?  Oh, it's going to be 24x30.  I have access to electricity and natural gas.

thx.

I have propane and electric heat in my shop.  I use propane primarily and the electric when I paint.  The electric furnace draws from outside through the forced air furnace and then into the shop.  The exhaust from the electric furnace goes through some of those sticky paint booth filters.  I know that this is not an efficient method to heat but I do not pull the paint-contaminated air from the shop back through the furnace.  I only use the electric when I am painting and I try not to paint on real cold days.  I think it is best to spend money on insulation and some thought on window placement.  I have windows in my shop doors, which face south and on the east side on my shop.  This lets the passive solar heat radiate and warm the concrete floor, which I guess must hold the heat well like a solar collector.   There are no windows on the north and west side.  We get most of the cold strong winds from the southwest and north during the winter.  I do not heat my shop at night and occasionally for a couple of days in a row and even during extended cold spells water will not freeze during these idle periods.

[GPster]

You can take information from all of these suggestions but you need to keep in mind the design temperatures of your local and what you want to accomplish for your comfort and need. I'll try to add a little thought to some of this. Air is a lot easier to heat than concrete or steel (floors, block walls, metal work benches, loaded tool boxes and shelves of temperature liquids like paint). Concrete and steel will tend to remain at a chosen temperature for a long time if the aren't subject to moving air, like from a furnace blower.  I like the idea of the heated floor and maybe there is a couple of additional features that you can also think about. There are some household hot water heating units that also have the added feature of hot water for use in the household sense. Like if you would like to add a shower for clean-up or would want hot water for anything else ( like washing greasy clothes or rags). Also I have not investigated these ideas but if you had alot of sun in your area in the winter You might be able to come up with a way to suppliment the heat in the circulated water with the use of a solar panel. To me the thermostat should only have to think about keeping the temperature that you decide. The other points are valid but they may not all be valid to you. GPster

[parklane]

When I built my shop (30x42) I looked at all the types out there, and believe me, I'm a dutchman, so you know how cheap I am. After all the smoke cleared, we ended up going with the infloor hot water system, with 2" styrofoam (the pink stuff) under the piping. Then we used steel mesh, and tied the piping to the mesh with zip ties.You can have different zones in the shop , and adjust the heat by opening or closing the loops with a tap. The most expensive part was the 1/2" pex pipe, but it is much more durable than poly pipe. If you have the concrete mass set to 50-52 degrees, it works out ideal,and just leave the thermostat alone. I turned mine on in Oct. and left it on til April. Nothing like it!!    
John

[40]

I have used all of the heat sources mentioned above...my preferance...a hanging,forced air,natural gas,high efficiency furnace.My shop is 34X48 w/10' ceilings.It has 2X6 walls w/blown high efficiency cellulose insulation.I keep it 50 to 55 degrees continuously and it takes less than 10 minutes to bring it up another 10 degrees.I have frost footings and a foundation 48" below grade which probably accounts for my floor staying relatively warm.It costs on average about $25 to $30 per month in the winter to heat it...that is not an estimate as I have a separate meter for the shop.I have several stategically placed windows which help with the heating also.The unit I have is a 93% efficient Lennox brand and it cost aprox $1200 dollars installed including the venting.The in-floor heating worked OK for me but I didn't like the fact you had minimal control...slow to warm up/cool down when the temp changes quickly as it often does in the Midwest.Good luck!

[enjenjo]

I have a programable set back thermostat on a gas furnace in the shop. I maintain 40 degrees all winter, and have it programed to heat to 65 degrees at 9am.
When I go out to the shop in the morning, I fire up the wood burner, which will keep the gas furnace from running all day. It's worked good for about 15 years set up that way.

[Cword]

Another pro-floor heat anecdotal response

I buil 24 by 30 in 2000, and included floor heat.  If doing it again I wouldn't do it any other way.

My father has "instant heat" in the form of a huge overhead blower in a 30 by 30 garage.  When it's really cold out (-15 to -30) and I go to his place to spend an evening working I find you sweat like a pig while your feet freeze.  It doesn't become comfortable to work until the end of the evening and the tools, products and floor start to warm.
At home on the same type of days I let the floor idle at 5 to 10 C all the time,  The shop is comfortable to work in in a shop coat.  Tools and products aren't frozen.  It is a far more comfortable shop.  

My floor is heated by a 30 gallon water tank, I also have plumbing schematics and parts lists for the system I built if you'd like 'em.

mike