Thread: shop heating?

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I was wondering what others are useing to heat up their shop for painting?

I live in kentucky and we have mild winters. I keep my shop warm with a karosene heater and 2 220 volt electric heat when I need to paint. but the electric heaters do all they can to get the shop warm. without useing both and the karosene heaters the shop gets really cold. what do you suggest?

the shop is a 40x60 with a 12' ceiling. all metal building.

You didn't mention anything about insulation. You may be fighting an uphill battle.

As far as cost (even though you didn't mention it specifically) that's a local matter. Some places electric is cheaper than gas, others vice versa. Then alternatives like propane, kerosene, etc.

When I had my spray booth the air make-up had a 1 million BTU heater in order to maintain a spray temp around 80, and a bake temp of 130-140. Not exactly your situation, but it gives you an idea of what's involved to reach the optimum.

In a home shop a factor that's often not considered is pre-heating. It works especially well in a steel building like yours. Just because the air temp got up to, say 65, doesn't mean the beams and pillars did. They become heat sinks and sap the heat from the air. If you pre-heat the area and bring the structure and it's contents up to temp, then you have the benefit of some radiant heat, as well as these pieces not "stealing" heat from the air as quickly. Yep, it costs more time and money, but then so would a larger heating plant. BTW, some people swear by overhead radiant heaters as a solution, but in reality they're very directional. That's good if you're trying to focus the heat in a portion of the work area, but not so good if you're going for overall heating. Also, in floor radiant heating is nifty, especially if you work on the floor a lot, but is tough to do in a retrofit scenario. Again, it follows the principles noted above, you still need to pre-heat the structure and contents.

good point.

my shop is located in a rual area and the only way to heat is with propane, kerosene, electric. the old way was to use a wood or coal burner. but they have many drawbacks

my shop could use more insulation. I will try that first. thanks

would a 220 volt electric furnace preheat the shop and help heat the shop for painting. know of any electric furnaces that could put out enough BTU's?

It depends on the furnace output and ambient temp. The smaller the heat source output, the lower the temp, the more time/effort needed. Insufficient heat output or too low a temp and you may not get there (eg the output of a light bulb won't get there at 0*F)

Here's a table to convert watts or kilowatt (your electrical rating) to BTU http://www.energy.iastate.edu/renewa...18_apen_a.html

To me, a heated shop is really important. When I think of working in the shop, especially after hours, I would find a heated shop most inviting. I am in the midst of starting to build a small shop, and what I am doing is installing a “radiant hot water in floor heating system” fired by gas.

This works well in a new construction situation, but as Bob mentioned, if your shop is already built, you might not want to go the distance with this type of heating. Although you could get away with a two inch concrete slab over concrete, which really wouldn’t be all that much more cost over new construction, probably about $1,500.00 plus the heating system itself. The problem would be that you would have to remove everything from the shop for a week or so.

To my thinking, “in floor radiant heat” has some serious advantages in a shop. First of all, it heats from the bottom up, which means the area where you are working has priority. This is in stark contrast to forced air heating.

Furthermore, if ever you need to lay down on the floor, you might not want to get up, cause it will feel so user friendly. This is very significant. I believe that a lot of illnesses and back aches etc, come from men not taking care in the area of keeping one’s body warm. A recent study showed that those people who kept their feet warm, were far less likely to catch a cold, flue etc.

Now take into consideration the fact that no air is being pushed around = no dust or paint movement to areas which you might not want to contaminate or dust on your new paint.

In all other forms of heating, the air closest to the ceiling has to be heated before the lower air is warmed. The heating works from the top down, even with those electric and kerosene heaters which you mentioned. Yes, they are positioned on the floor, however given a short distance away from the heaters, the floor and the air remain cool.

Add to all this, if your shop had no insulation in the ceiling, it wouldn’t make a huge difference with “in-floor-heating”. Why? Because a “radiant-in-floor-heating-system’s” priority is within the fist eight feet of the floor. Of course there will be some heat loss, but not to the degree as those systems which have to heat the upper eight feet first to about 80 degrees before the floor’s air even hits 50. An “in-floor-system” would heat the floor to say 60-65, (which is really all you need at the floor in a shop) and the air at the 12 foot ceiling mark might only hit 50-60 at that point. Given a few hours, the air next to the ceiling would obviously warm up.

The other thing to take into consideration is this. Once the slab of concrete is warm, it becomes a thermal mass and takes hours to cool off. So what I’m going to do is have a programable thermostat which will start the heat an hour prior to start-up time and shut if off three hours before shut down time.

As for which type of fuel you might choose to heat the floor, this would depend on the fuel costs in your area. A gas boiler is usually cheaper but an electric boiler might be less costly over the long run.

All good points typhoon.

I feel compelled to mention my other repeated warning whenever talking about heat, even though 57 sounds like he wants to go electric, this would apply to the kerosene heater though. Never work on flammables (paint, gasoline, carb cleaners, etc.)when there is a flame heat and/or ignition system. That includes, but not limited to, pilot lights for water heaters, clothes dryers, furnaces, heat source for the in floor radiant system and so on.

yes . I have been heating the shop up for hours and then I would shut the karosene heater off and sit it outside to cool off. and I would move the electric heaters far away. but this makes the shop cool down to fast. and has made a paint job dull over like it was a fog overcast on it, and I was told it was because the paint cooled down to fast.

so I really need a new heating system. when the shop was built I was on a budget, I paid contractors to do the slab and erect the metal building , no wiring . I did the electric myself, and had it inspected by a state inspector. there are no plumbing in the shop just yet. my service panel is rated for 200 amps. and I run 4, 220 breakers. 1 for aircompressor, 1 for welder, and 2 for electric heaters. I used insulation that is in a roll and has a white outer layer. its all exposed. but I think I will get some of the insulation sheets 4x8 and some 1/4" plywood to help .

this shop does get cold inside. but it beats working outside in the driveway.

speaking from experience and cold weather i agree with bob , insulate your building, metal walls have almost 0 insulating factor . it just holds the air in but the heat just leaves.
i have a neat 30 by 20 10 ft wall 12.5 ft ceiling prefab metal building with a 2 inch thick wall tin outside r 12 insulation sandwiched in between and then complete tin walls inside i would consider it the minimum for this county.
i heat it with a desiel furnace from a mobile home. this gives me enought heat to preheat the building enough to do a little painting.
try to track down a fuel oil furnace out of a old mobile home . the are tall and thin take up little space. mine uses 3/4 quart per hour running full blast and will heat any decently insulated building.

What about a couple oil fired house furnaces, 1 at each end but run the ducting to the base of the walls and if you don't have a lift overhead, run a couple near the celings, but maby at 10' pointed down, and keep the 2 furnace ductings connected togther, run them both to digital thermostats that do not need to be leval, that way you can have the furnaces fire up in the morning and go to 40* after a certine time at night, then fire back up in the morning, so it's warm when you get out there. I'm shure with the right insulation and using your electric heaters on really cold days or painting days, and it would work good

I am using a LP fired salamander right now and its OK ,I am gonna try one of these if I can find one locallyhttp://cgi.ebay.com/Mr-Heater-Radian...QQcmdZViewItem my barn is 25 x 40 block ,I wish I had put in radiant floor heat when I poured the floor ,a friend of mine did his shop with it and I really like it

How about building a room inside the shop for all your prep and paint work. You could insulate the heck out of it . A smaller space would be easier to heat. Kind of a low tech paint booth. With a 40 x 60 shop you have plenting of room.

A couple of weeks ago I bought some sheet insultion for my garage door.Its the kind that comes in different sizes 1/4 "X4'x8',and 1/2",3/4" sheets also.It is also covered with a thin aluminum foil on one side,and reflects light.It's like 10 dollars a sheet .Don't forget the door. It will also help keep the cold air in.It doen't weight much either.I carried four full sheets to the truck across the parking lot,and I was suprised how light they were.I also use karosene heaters,but hate the smell. I am using some stuff called klean heat .It's label says ODORLESS karosene.It still smells a little ,but not as bad as the regular stuff.I think its expensive though, 9 dollar a gallon .

Originally posted by Bob Parmenter
All good points typhoon.

I feel compelled to mention my other repeated warning whenever talking about heat, even though 57 sounds like he wants to go electric, this would apply to the kerosene heater though. Never work on flammables (paint, gasoline, carb cleaners, etc.)when there is a flame heat and/or ignition system. That includes, but not limited to, pilot lights for water heaters, clothes dryers, furnaces, heat source for the in floor radiant system and so on.

Thats a good point also ! You need a GOOD exhaust fan ,to get that crap out quick.

I also would suggest a oil furnace. You already have the electricity available and oil furnaces are more easily moved if you want or need to move it around to another location,of course thats considering there is no trunk line and branch runs. Heat output can be whatever you need ( btu wise ) and CO can still be a danger with oil, it is something to keep a watch on in a shop setting. Of course flame and spark dangers are extremely dangerous in any shop. Any fossil fuel furnace in a shop will need maintenance and safety checks,,,,,every week to be safe, have a professional do it. Keep a clean oil,air- filter and nozzles in it and check oil quality often. I have a smaller metal garage and electric heat and a wood burner do OK, especially on a 40 deg. day when the sun is out for hours. Fossil fuel appliances in a paint shop can be as deadly as dynamite,,,follow all code and safety recommendations. One other note, ,, on sunny days I paint because of the added heat and with a furnace 'outside' of room air,meaning that it does not use garage room air for combustion air and is safely isolated from garage room air there is no danger of garage vapor explosions, but even with an isolated furnace there is still the need to seal off return air from the combustion chamber and check that weekly also, better be safe than sorry.

Originally posted by dreamrod57
I was wondering what others are useing to heat up their shop for painting?

I live in kentucky and we have mild winters. I keep my shop warm with a karosene heater and 2 220 volt electric heat when I need to paint. but the electric heaters do all they can to get the shop warm. without useing both and the karosene heaters the shop gets really cold. what do you suggest?

the shop is a 40x60 with a 12' ceiling. all metal building.

i heat a 30x30 garage with electric furnace
insulation is just foam. on days that are above zero i can keep it at 70 or above pretty easy when there below zero still can get it to 70 just not as easy. Most electric furnaces have five coils in them i only use two of them. 220 electric furnace is different than a 220 space heater because a space heater is just what it says space heater. a furnace reuses warm air along with a blower motor that doesnt cool the coils to fast. cost only about 100.00 bucks a month to run and dint have to cut any hole in my roof