I know I may be asking for a miracle here, but I'm going to try it anyways just in case I'm overlooking something.

New (less than 10 yrs old) 2 car attached garage, that is "insulated" but the quality is questionable because of "cheap" builders. my wife keeps her car indoors in the winter, the other bay is tools, machinery etc (lathe, mill, all the goodies). Last winter while I was on deployment a lot of my tools got rusty. Now that I have a lathe and mill in the garage I definitely want to prevent this. I don't want to fully "heat" the garage, just keep it 10-15 degrees above outside temp to keep the moisture from condensing.

Firewood is abundant at my house, I already heat primarily with wood. I would love to put a wood stove in the garage but there are a few problems. The investment in a 2nd Class A chimney to do it right is pretty big. I don't really want to do many more permanent changes to the house (trying to avoid another hole in the roof). I don't plan to live in this house much more than 5 more years and that means I'm going to have to sell it. It's in an "upscale" neighborhood and I don't want to make it look too much more "redneck". The firewood stacks, beehives, chimney, etc already make it look a bit redneck; 2 chimneys would be the icing on the cake. Another problem is the garage is pretty "tight" as it already is so something ceiling mounted or low-profile wall mount would be ideal. One problem with that, no gas service here :(

I could possibly crack the door between the house and garage to allow things to heat up a bit every once in a while, but the problem is that my stove is already pushing max output to heat my whole house, heating the garage isn't going to work on colder winter days....

Obviously vent-free devices are out of the question because they won't help with moisture problems at all.

So my options are:

Small wood stove in the garage:
Advantages: nearly free operation, could fully heat the garage and not be a problem
Disadvantages: larger initial investment, another hole in the roof, takes up quite a bit more space

One variation to this would be to route the chimney through the window avoiding the hole in the roof, and I could take the stove/chimney with me when I move. Not ideal, but I've thought about it quite a bit...

LP options would have to be direct vent and I will have to buy or rent an LP tank (unless I use small grill size tanks), not to mention the cost of the LP.
Advantages: cheaper initial investment
Disadvantages: higher operation costs

I guess I'm just looking for some ideas in case I haven't thought of it all yet....

What do you think I should do? I know what I really want to do is to just do it the cheap way and get a cheap cast iron stove, run the pipe out through the garage window, and run like that for the few years I plan to be here. But I'm concerned about how redneck it will make me look...

Are there any other cheap and easy ways to keep my garage just warm enough to prevent condensation?

Possibly look into a Toyo stove. They run on fuel oil, but don't use a lot of it. and they can be pretty small.

I would either go with a propane vented heater like the Mr. Heater or maybe a radiant tube heater (Mr. Heater makes on too but they are more money)

My shop that I am building has a vented propane Mr. Heater and I like it.  Works really well.  Northern Tool has them on sale from time to time.  

I'm guessing that you'll need one of the 45k btu units but I don't know the size of your garage.  

You can buy a 100 lb propane tank for about $130.  Or, watch craigslist.  I've seen them for $60-70 new on craigslist.

Don't do a wood stove unless you are willing to invest BIG $$$ in your chimney.

wall vent a wood/kerosene drip  and install a good heat exchanger on the stove pipe.

key words: virtually free wood



Get a pot belly stove.  Buy one as efficient as your budget can afford.  If you add an inline scavenger for the exhaust with a blower, it substantially increases the efficiency.

Careful with those. They can decrease the EGT too low and creosote can build up in the chimney can plug up and you could have a chimney fire on your hands. Use these only with very dry hard woods, and keep a thermostat on your stack above the scavenger.

 

Move to Florida, problem soloved. Then you will be on here asking how to cool off your garage.

Only install a wood stove if you are willing to spend big bucks on a chimney.  

I think in some areas, wood stoves are prohibited in garages.  Might check your area.  Also, check with your insurer.  They may not cover you if you have the wood stove.  

Garages typically don't need as much heat as a house.  

Not being able to see your existing set up and layout makes it a little difficult...   That said get inventive, my first thought is
to expand/improve your current wood fired heat system to do what you need it to.  add a DIY box in the stove pipe to scavenge additional heat.  
This could be similar to the old school magic heats (ducted out to the garage?), build a box, heat some water (copper tubing comes to mind), pump it out to the
garage (not pressurized) use a large truck heater core, or a radiator, run forced air through that once the water is in the garage.

  My first choice would be to move to a system which takes care of ALL your heating requirements, done properly it would add value to the home.  

A little TOYO  oil heater should do the job.
Set it around 50 degrees,  probably burn less than 20 gallons per month.

My brother has one that burns used motor oil. I'll find out what type, if you're interested in going that route.

It doesn't sound like your problem is heat, but rather moisture.

A 6 foot baseboard electric heater can be very drying. I have one in my garage and don't have any issues with stuff rusting.

Another alternative is a small dehumidifier, but in my opinion, they cost more to run than a baseboard heater.

Let us all know what you decide to do.

+1 to this.
Insurance companies don't like to see a wood burner in a garage. They don't want a woodburner in any building that has vehicles in it, according to my insurance agent.

I'd look at an electric radiant heater. They are 220v, but they use very little electricity. You could mount it overhead, or on a wall. It doesn't take a lot of heat to keep our garage above freezing, and keep the humidity down.

Our heat source is natural gas. We installed a thermostat that I can dial down to kick on at 35 degrees, and shut off at 37 degrees. An electric heat source should be as cheap or perhaps cheaper to run than our natural gas unit.

ETA; Baseboard heater might be practical, too. Not sure which would be more efficient, baseboard or radiant. One thing you can't argue though, heat rises.

I like this answer.

I would not do a wood burning stove.  you cant be there all the time to fire it, and do you really want to keep an eye on it at all? secondly, gasoline vapors may be there.  I had one in my detached garage for use when i was in there. the old owner installed it, but it was a super pain to use because it took long to get hot. now i use a kero turbo heater.



seems like some blown in insulation and a 6 foot baseboard heater on your side of the garage would work. I think the moisture is coming from the snow and rain from the car.



i bet an wall mounted fan would help quite a bit.

Nah...  I love my job, I love my family, and most of all I LOVE living in Indiana...


Well, that sounds great, but probably not going to happen. The current setup is only 2 years old and is "perfect" for this type of house. I don't want to modify it at all, I just want to keep my crap from rusting in the garage. Also, it's not a problem with heat extraction (it's a modern high efficiency wood stove), it just overall capacity. I can continuously stoke it and on the really cold days the problem is that the firebox fills with coals and they don't burn down fast enough to allow more wood. Installing a woodburner in the garage will allow me to transfer coals to the garage to burn down further w/o wasting them and I can in turn keep the house warmer...



When I installed the stove in the living room a few years ago I called my agent and asked about a wood-stove, he didn't have much to say other than, "Doesn't change a thing, we don't need anything from you, it's all insured the same" We never discussed where, how, why or anything so I imagine its not a major problem to have it in a garage.

Electric isn't happening plain & simple. I have the most expensive electricity provider in the entire state and I refuse to pay them a penny more than I have to. Electric is definitely MUCH more expensive than gas in my area.



I'm already here all the time to tend to the woodburner in the house, one in the garage isn't a big deal... Only gas vapors would be from the car, the mower and all gas is stored in my shed.

Moisture is certainly coming from the meltoff/rain from the car...


Thanks for all the suggestions guys, keep them coming... I'm starting to get tempted to go the wood route even though it'll cost more up front. I think I can do it with no permanent mods to the structure by running it out through the garage window... I figure $1500-2000 for cheap stove and the proper chimney setup.

2nd to that is to just suck it up and do some sort of direct-vent LP system. The Toyo heaters sound great but I'm not completely sold on them yet. I figured up about $400/year fuel cost running the Toyo Laser 30 (smallest one they make) on low.
The benefit to wood is that I can stoke the fire when I get home from work, and the garage will be toasty warm by the time I get changed, eat dinner, then go outside to work on a project etc. The added cost to run the garage toasty warm is VERY minute compared to the other options where I have to buy some sort of fossil fuel to get it that much warmer...

here is a link for a waste oil heater you can build real cheap. http://journeytoforever.org/biofuel_library/ethanol_motherearth/me4.html

Part of the problem is high humidity , gotta control that as well .

Yep.

Strange as it sounds, the solution might be as simple as moving moist garage air outdoors, and drawing in dry outdoor air to replace it.

These things do a great job and in my experience are pretty cheap to run (as far as electric in my AO). I think some of them can be converted to 220. Gotta keep the insurance in mind when discussing attached garage and that discussion likely leads to no open flame.    I had the same problem with woodworking equipment rusting and I didn't want to leave the shop heated overnight or unattended torpedo heater. It didn't heat the shop but kept the chill off to prevent condensation. Install behind the mil or lathe and it becomes a heat sink...  
Ceramic Wallmount

Uh?  Oil your machines. Thats how we do it........

We only heat the shop when we use it. The machines do sweat. We hit them with kroil and we keep most of the rust at bay. The worst is a little superficial rust on the chucks and vises if we don't oil them. Having pretty machines never occured to me to be necessary. The slight rust actually protects the metal once it is there as long as its oiled up after.

This sounds good, but the machines sweat in the warm air as you heat the shop to use it. Working with machine tools in the cold sucks.

How about a dehumidifier? I bet it'll run on LOTS less electricity than a heater!

eta

...and it'll be appropriate in summer as well as winter.

in all probability your local building code prohibits a wood stove installation in a garage.  even if such an installation is not specified, i would think long and hard about this approach.

you would be better off with an outside wood-fired boiler and then installing underground insulated pipe to the garage.  the chances of your garage/cars/tools blowing up drops to zero.

nevertheless...

as noted above, i agree that your problem is humidity –– not necessarily temperature.  in fact, warmer air could make your problem worse in two respects.  first, warmer air holds MORE moisture.  if there is a source of moisture, such as a damp concrete floor, more of the water vapor is going to be held by the warmer air.  it's just physics.    second, unless you keep the temperature relatively constant, you are asking for a condensation problem.  and guess where that condensation is going to occur?  condensation is the result of localized air temperature being lower than the dew point of air containing moisture.  this is why when you take a cold glass of iced tea outside in the summer, the high moisture in the hot air condenses on the outside surface of the glass.  

you may end up with the same problem with your heavy equipment.  start: cold room, cold equipment, high humidity.  when you turn on the heat, the room air temperature will come up MUCH faster than the heavy equipment could possibly.  steel/iron equipment that weighs a thousand pounds takes a long, long time to heat up.  until it does, the hot, moisture laden air will result in condensation on the cold surface of the equipment.  the very same situation as with the glass of iced tea.  again, it's just physics.


a dehumidifer is probably going to get you farther than a heater, and it will be cheaper as well both on initial expense and on operation.  but you should first find out where the moisture is coming from.  ground saturation due to poor drainage?  collection from downspouts?  improper grading of surrounding yard?  too much tree cover?  


get rid of the moisture.  then it doesn't matter what the temperature is.  look at those aircraft sitting in the arctic circle for 50 years; they are in perfect condition.  very cold, but no humidity.

ar-jedi

Do you have a south facing wall that will allow passive solar with a heat box? Having one on my shop helped sell our old house. It also saved lots of money in what it would have cost to heat with electric, or gas.

http://www.motherearthnews.com/renewable-energy/2006-12-01/Build-a-Simple-Solar-Heater.aspx

I used to run a small business out of a detached 2-car garage. In the dead of southern middle-Tennessee winters we'd get down to maybe 25F, so it really wasn't that cold, but I wanted some heat for long evenings and weekends in the shop.

What I arrived at was running a small LP forced-air heater (like this: http://www.amazon.com/Mr-Heater-Propane-Forced-Air-MH35FA/dp/B0000C6E3H/ref=sr_1_1?ie=UTF8&qid=1347113733&sr=8-1&keywords=propane+forced+air) for about 30 minutes, then switching over to a small Buddy heater (like this: http://www.amazon.com/Mr-Heater-F232000-Indoor-Safe-Portable/dp/B002G51BZU/ref=sr_1_1?s=home-garden&ie=UTF8&qid=1347113794&sr=1-1&keywords=buddy+heater), both running off of 20-lb bottles. This worked very well for me, and gave me some backup in case one heater or the other failed or emptied its bottle.

The small forced-air heaters will literally sweat you out of a small space, so you don't have to run them long to get your temp up. The Buddy heater is best placed near your work space.

One warning: in very cold temps, don't run the forced-air heater too long in an unvented space. A CO alarm is a good idea, too. Also, for Buddy heaters or any other propane appliance that uses any real amount of fuel, the little 1-lb bottles tend to freeze-up under cold conditions and high-fuel flow. They aren't nearly as bad as butane-burners, but they can freeze and stop working. I've never had this happen with the 20-lb bottles, but then again I am in the South.

Buy/ Build waste oil heater.
Do own oil changes/ get waste oil from everyone you know/ ask for it from shade tree shops.
Burn waste POL.
Win!
Seriously, the shop I used to work in water well drilling had a 200 gallon tank we'd dump all the waste oil in; diesel, motor oil, gas, hydraulic fluid, whatever.    It would get filled all summer, then the heater would run off it all winter.  It could keep the shop at 90 degrees with the bay doors open too!    
Another thing is to take a look at your insulation, and venting.    If there's no airflow through the garage, it'll definitely build moisture.    How many and what size of vents are there?    One option might be a power vent on a humidistat  (think thermostat for humidity).   I.E. wet car pulls in garage, power vent kicks on, sucks humid air out, turns off.
 

How about one of these  Window mounted pellet stove

No new chimney
It fits your budget
You can take it with you when you move
Simple to run, for when your on deployment

This is exactly right.  

It will eliminate the humidity issue completely and puts out 'warm' dry air in return.

I've been using the one below for several years and can't recommend it enough.

Link

ETA: not cheap, but not cheaply made either and with a solid warranty.  

Here's mine.  It's not completely installed in this pic.




Vent outside of the shop.  

Dryer vent will add a lot of moisture.

There are all kinds of options. If it is just humidity you are worried about, your cheapest option is an exhaust fan run off a humidistat. You will need an inlet grille as well.

You seem to be fixating on heat. Most cheap heat will end up adding humidity to the garage, although it probably won't matter much, as the air can hold a lot more water without it being an issue as the air temperature gets warmer.

both will add to his moisture problem,

I'd look at a propane vented wall heater or the electric base  board.  My buddy's dad put the wall heater in and it was outstanding.  He'd keep it at 55 degrees, he didn't need it house hot, just warm enough that he could glue and paint his wood projects and they'd dry w/o freezing.

paul,

take your meds man.

seriously.  

he wants the moisture OUT of the garage, not IN.

ar-jedi

unvented propane heaters add a ton of moisture to the dwelling.  

during combustion, 1 mol C3H8 propane is oxidized via 5 mol O2 (which gives off lots of heat), and the (optimal) chemical result is 3 mol CO2 and 4 mol H20.  the first part is harmless carbon dioxide.  the last part is water –– and a lot of it.  if the combustion process is just a tiny bit inefficient, you not only get CO (dangerous carbon monoxide), but you get twice as much water as well.

http://en.wikipedia.org/wiki/Propane#Properties_and_reactions

ar-jedi

Correct. This setup worked well for me because I was only using my shop space 20-40 hrs per week, and only had to heat the space for part of that time. When I wasn't using the space it was continuously vented through windows and a slightly-raised garage door in the Winter, and it was kept dehumidified during the Summer with a window AC. This scheme absolutely will not work if the space isn't vented well when not in use. You'd end up with a very humid space. For that matter, the increase in humidity is very apparent when the heaters are running–– particularly the forced air heater because it burns fuel so much more rapidly.

Neither of those heaters should generate much CO, but there's always the risk of a mechanical fault. If the regulator and/or valve fails on either type of heater you could end up with too rich of a mix and thus generate much more CO than intended. A CO detector is a good idea anywhere these types of heaters are used.

Baseboard or forced air electric heaters (available in 120 and 240 VAC) work well. No exhaust to worry about, are basically 100 efficient, do not add moisture to the garage, and very affordable to buy and install. Downside is electric bill, but that is still probably cheaper than propane/fuel oil. Also, with electric, you will fly under the radar as far as smoke stacks out of the garage. We use electric to heat our house. I can't even mess with wood for how cheap our house heats (no more than $250/month in heat in the coldest months here in MN). Should make note my electric is half price because we are on the duel fuel setup. We use portable kero heaters when we need heat and the electrics are off.

How is the air flow in the garage?  Is there any roof vents?  If not, some won't hurt.

I'm 99% certain its not an issue. Indiana is pretty free, and I live in an unincorporated/unzoned area, which means I don't need to follow jack-squat according to IN code if the dwelling is my own. My house just has to conform to codes if I try to sell it, which isn't a problem because any wood-burning systems will be removed before selling.


No way is that happening... I considered outdoor boiler 2 years ago when I installed my stove in the house, too expensive, too much wood consumption, and not ideal for my subdivision or land-use. No way am I spending $10k plus initial investment just to keep the garage warm.


If I'm not mistaken, as the air is heated up, unless there is a source of moisture being added to the air it won't condense back out because the relative humidity will be decreased as the air heats up. But I could be wrong. Either way, a wood-burning appliance would easily solve that problem because it would be continuously drawing the moist air in as combustion air and replacing it with dry outside air.



Nope




That is exactly the type of outside of the box thinking I'm looking for. Granted, I will still have to buy my "fuel" but that's not a totally bad idea. I would have to sit down and pencil out the costs involved in that vs. some of the other suggestions, but I really do appreciate the suggestion.



Heat just seems like the most logical option. Raise temperature to reduce relative humidity therefore reducing condensation. The only "cheap heat" options that add humidity would be vent-free LP and dryer vent type things. Most other forms of combustion either vent outside, or don't add any significant moisture as a product of combustion...

Dehumidifier isn't out of the question, but cost vs. benefit is much higher from my stance. If I can fully heat the garage to make working in it comfortable in the winter it's an added benefit...



Just to put things in perspective for those that still insist on suggesting electric options. Before I added wood to my place my heating bills were $400/mo and that was w/ the thermostat at 58 degree and only heating part of the house. My neighbor who has a similar house to mine (same builder, similar layout and sq footage) has electric bills that routinely break $1k in the winter. So pure electric heating (anything that is resistive electric) is 100% out of the question. Like I said, I have the most expensive electric provider in the entire state of Indiana, I'm not giving them a penny more than I absolutely have to. Just to further expand upon the expense of electric, it's actually a selling point that is often listed in real-estate listings when a home is not in XYZ electric coop's district.

I wonder why there can't be a propane widow heater?

That's a good question...

I've been wondering if he wants to use wood and it's free why he couldn't  use a fan with heat exchanger connected to a stove outside of the garage but under cover or in a lean to bldg?  Keeping it going would not be fun to me, but his goal was cheap and he asked about it.  The stove would need periodic maintenance but be worth something for outside cooking at times you don't want heat inside and/or relocation/barter if things get bad.  Might not be optimal heat for living, but might do OK for his garage goal?

nm...

That's why electric is completely out of the question, I'll freeze my arse off and spray everything down with oil before I go with electric heat.

I think I've pretty much settled on wood. My wife found a nice wood-stove for $50 I'm going to go take a look at it. Chimney/flue should be around $1100-1500 if done right. I think i can swing that, and then I can heat my garage to a toasty warm temperature.

What about building a temporary wall made of cheap materials(2-bys and OSB or the like) between the bay that is used for the car and the one that is used for the machines?

A smaller, confined, and DRY space is much easier to heat than a larger, open one that has a snow-covered car in it.

Even using some heavy plastic "drop-cloth" type sheets tacked into place to seal-off your workspace will help quite a bit.  

Then just use a kerosene/propane/whatever portable heater to take the chill off a bit.

And when its too warm to run the wood stove you will still have a moisture issue.

You should consider a dehumidifier for moisture control and address temp/comfort  separately.

this post needs to be repeated, again.

ar-jedi

the garage has 1 large door for both bays...


First of all, while I appreciate the suggestion, I'm not a retard. I understand that it is a moisture problem and that in certain times of the year I may still have moisture problems. That being said, 95% of my moisture problems occur in the winter when it's cold and the garage has a car with wet snow/slush packed on it pulling in and melting off every few days. I asked for suggestions on a heater because heating the air (decreasing relative humidity) should solve this problem. A wood-stove will further solve the problem by drawing the humid air into the stove and out the flue, while drawing fresh air into the garage from outside (acting like an air-pump). I came here simply for outside of the box ideas on heating before I committed to one way over the other. I got a few suggestions for great ideas, but ultimately, fuel for them is still expensive. Wood is relatively free, and with a slightly larger initial investment, I can keep my garage warm for a very low cost of fuel by going with wood.

I can handle the other 5% of the time when moisture may be an issue.

spray it down anyway