I have an unheated garage shop. My wife wants me to put in some type of heat that I turn on just when I’m working. It seems to me that would be a terrible condensation problem to cycle the shop from below freezing to warm. Does anyone have a problem with condensation with temporary heating in a shop?
trimjim
Replies
Jvk, I'm in the process of heating my shop. I'm leaning towards a pellet stove, Thermostatible and safe. Pellets aren't that bad in cost. Look into it.
-Lou
Lou, I've had a pellet stove in my shop for 2+ years now. I thought it was a good idea when I bought it (used) and still do, but there are a couple of things to keep in mind:
It runs on a circuit board, so be sure you have a quality surge protector between it and your electrical outlet, preferably one with a $5,000+ guarantee
Pellets are a waste product of the construction industry, and can suffer sudden bouts of scarcity. Last year, I think in January or so(?) the became non-existent here in the Seattle area for at least a month. I mean notbody had pellets! Really tough for people who's sole source of house heat was their pellet stove. So, it's a good idea to keep extra stock around.
My control board died, not sure why, not long after I got the stove, which is an ancient specimen with parts no longer available. I control it manually now, after the repair guy installed a $300 timer-block gizmo that controls the auger's turning time. Lost the ability to use a thermostat. Envy you getting a new stove!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
jvk,
So far this is just theory, so take it with a grain of salt. I'm in the same boat, unheated shop that I'd like to just take the edge off while I'm working. To avoid the warm air/cold cast iron condensation problem I bought a couple of electric radiant heaters. The theory is that a radiant heater warms people and things (like cast iron) which in turn heats the air, hence, no warm moist air hitting cold tool surfaces.
I bought a larger radiant heater from these folks [email protected] . I'm going to hang this over the main work area. Also a couple of days ago someone posted a picture of a $79 radiant heater they got at Sam's club which comes with 5 mounting brackets (thanks for the post by the way). I also bought this and will put the brackets around the shop at different work stations for those times when I'm spending a good portion of time in one place.
I'll let you know in a couple months how this works out :)
Mark
It depends on your climate and how you're heating, but probably not. Heating the shop doesn't by itself add moisture to the air, so you're okay in that respect as long as you use a heater that either doesn't emit any moisture at all (e.g., electric) or vents it to the outside (e.g., direct-vent gas heater, wood stove, etc.).
Then, as long as you don't have strong temperature gradients in the shop (i.e., everything heats up and cools down more or less at the same time), you should be okay. The only time you need to be especially careful is in cold, wet weather. If it's cold and rainy outside, you probably want to leave the heat on until the weather dries out. (You just want to be sure that the temperature in the shop is at least a few degrees above the outdoor temperature.)
-Steve
You will have problems with condensation. You can lessen it if you use radiant heat like Mark said. I did this for a couple of years and finally broke down and did it right...http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200307959_200307959
You can get this same heater to run on propane also. If you have NG or propane heat in your house now I think you are crazy not to take the time and money to do it right. They have forced air venting so they can be vented horizontally out the wall instead of cutting a hole in your roof. If you do the job yourself it can be done in a day with a total investment of less than $550.
I keep mine set at 45 or 50 degrees when I am not in the shop and turn it up to 60 when I want to work in there. It takes minutes to warm up. If the little woman has a problem tell her how nice it will be to get into a warm clean car in the morning.
If you decide to go with temporary heat make sure you protect your cast iron tools with something like Boeshield T-9. I do that anyway as it makes them nice and smooth and a pleasure to work on.
Ok this may sound dumb but hear me out. The reason we get condensation on tools and such is they are cooler then the air and the air has humidity in it. The colder the tool in relation to the air the worse it is but more importantly the higher the humidity in the air the more condensation you get. This is the same thing that puts due and frost on the grass and car windows.
So if we can not get the temp of the item up (because we do not want to keep the shop that hot) then could we get the humidity down? I know we always talk about using a humidifier in the winter and de-humidifier in the summer (at least around here we do) but perhaps you could run the de-humidifier in the winter and keep the humidity down and this should (I would think) keep the condensation down also, no?
I am wondering (personally) about putting a de-humidifier in the shop for summer but that got me thinking about using it in the winter. One with the auto settings to control the percent of humidity I would think would work. Of course I guess if the shop was below freezing it would wipe the thing out as the water would freeze, and of course the colder it is (air temp) the less likely the de-humidifier is to work, but it may be worth a try in a shop that only goes down to the 50s or so.
Doug
Doug,
In theory that would probably work. In practice I think most dehumidifiers will ice up the coils at any ambient temp below about 60 to 65. Remember they work on the principle that cold air cannot hold as much moisture so they basically are running air over cooled coils. I tried that in my basement once in the spring and my dehumidifier had thick frost on the coils in an hour or two, but no water in the tank after a full day of running.
If you can keep the shop above 50 warming it up to a comfortable working temp. won't cause a condensation problem.
Rob
Yes, you may well have a condensation problem. The air will warm much faster than the cast iron or other large metal masses. Because the cast iron is cold, a small, local weather system will be formed in the air near the iron. This temperature difference creates the condensation. Just think of your beer can when it gets condensation on it. Same thing will happen to your tools if there is a temperature difference between the tools and the air.
Couple of things you can do. One is to keep you cast iron tools covered with a blanket that is air porous. In addidion, put a lighted 75 watt bulb under the covered tool. Keep your cast iron well protected with Boeshield T9--wax is not a good choice as it has no resistance to watervapor. Keep your shop at at least 45-50 degrees when you are not in it.
My garage shop is attached, and one wall has a gas fireplace on the other side, so that wall never gets cold, even in a Canadian winter. It's reasonably well insulated, including the door. I've been leaving an oil-filled electric rad on permanently in the winter for some years now without any condensation problem. I leave it at 50-60 overnight, and it isn't as expensive as I thought it would be -- barely noticeable on the hydro bill. With decent insulation, 50 is easy to maintain, and metal isn't going to undergo much of a change when you turn the heat up during the day.
Jim
I'm in a humid coastal area in the NW. I've insulated walls and ceiling and covered the conrete floor with t&g plywood. My shop has a double door to the garage and a 2000W wall heater.
The room stays comfortable in almost all conditions with very little use of the heater. The insulation keeps it stable and avoids the extremes of bare walls/studs.
When it is very cold I sometimes use a mechanic's drop light with a 25W bulb hanging under a couple tools covered with a drop cloth or some such. Just pennies for lots of warmth radiating in an enclosure. I do the same in my mechanical room for the water system. It is not heated but I leave a 25W bulb on to keep humidity down. It works very well.
Just keep all heat sources from contacting anything flamable, of course. That's why I like the drop lights. They are caged and can be suspended away from covers, etc.
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I meant to answer your post earlier but lost it in the shuffle. Just found how to work the search button.
I think that you will find that without infiltration or addition of water that as you raise the temperature that the relative humidity will decrease. Notice that the total humidity will stay the same. The total humidity is the amount of moisture in the air. The relative humidity is the amount of moisture in the air, expressed as a percentage, as compared with the maximum amount that the air can contain at the same temperature
Hence, at no point in the transition of raising the temperature to room temperature or lowering the temperature back to the original temp will it be as likely to rust as at the original temp. This is true only if you don't add extra moisture along the way. Note, that your body puts out a minimal amount of moisture through breathing and perspiration while in the room.
Through the years of managing apartments, I have found that when the heat goes on even a little bit the relative humidity plummets. If you maintain even a little heat in your shop, any potential rust would be minimized.
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