Garage Heating

[Burger]

Just wondered if anyone else here is as 'nuts' as I am and heats their garage through winter. In which case, curious what forms of heating people use?

I've been using a 3kw electric space heater but I'm thinking there might be more economical ways to achieve the same. I'm not so much after warmth in there as I am keeping a constant temperature above freezing and the humidity low.

 

[Will]

Would a de-humidifier not be a better option perhaps?

Will

 

[Burger]

Not really Will because while it might dehumidify it wouldn't keep the temperature above freezing.

 

[Will]

Are you sure? Most of the de-humidifiers that I have seen provide warm air as well as drying. I can't see the benefit of heating a garage without removing the moisture, otherwise surely you will just accelerate corrosion etc.

Might be worth looking carefully at draughtproofing and insulation - not going to help you wallet or the environment if you're pumping a 3KW heater throughout the winter

Will

 

[JohnDeere8530]

Not really Will because while it might dehumidify it wouldn't keep the temperature above freezing.

I use a large dehumidifer (ex hire) turned down to keep the air dry. Empty bucket about once a week.

To keep it warmish I raided a church skip a while ago.

They were putting in gas central heating and throwing out their old electric heaters.

These were the long plastic 3" diameter cylidincal type jobbies that went under the seats. Think they are about 150w/m. Think you can still buy them, they are water resistant so could well be the type that are fitted to greenhouses

I mounted these low down around the garage wall and connected to a domestic thermostat set to about 6C. This kept the frost off, total power output is about 1500w and it only kicks in for a few hours on a cold night. I estimate it to cost me about £50/winter in electricity

Remember to stop draughts and lag the roof and doors if possible. A car does not need to be kept warm, only frost free and at a constant as possible tempereature.

Use Optimate to keep the battery charged

 

[Deleted member 37751]

I would start by draughtproofing and insulating the garage, before I was looking at the heating problem, to be honest.

 

[jaymanek]

I was steered clear of heating a garage... moisture + heat = quicker rusting!

Buy a dehumidifier instead.. I have had two on full time for a couple of years now.

 

[kwakdonut]

Definitely go for insulating the garage, this does wonders for keeping the temperature constant.

I used a large roll of 'Space' insulation I got off EBay for about £40. Equivalent to about 150mm of polystyrene, it was easy to install and back it up with a small electric convector heater.

A dehumidifier is also a very good idea as already mentioned

 

[312 Sprinter]

As long as there is good air circulation I don't think there is any real point in heating the garage. Other than for your own comfort.

 

[Burger]

Interesting... I'll be the first to admit I know very little, if anything at all, about the science of corrosion. I have a temperature and humidity meter in my garage and having heated it in the way described for the last 3 years or so, here's what I know.

Without any form of heating the humidity in there is frequently reported as 80%+. Heating it reduces this to around 40%. In winter I always rinse my vehicles off after driving them on damp salty roads and then dry as much of the exposed stuff as possible before putting it away in the warm garage. Motorcycles are notorious for rusting quickly on exposed bolt heads and such, and in 3 years not a single vehicle is showing any rust.

I've always thought that by getting the humidity down to around 40% I was preventing accelerated rusting.

I'll certainly take a look at dehumidifiers, but I like the idea of keeping the temperature up as well... especially when I want to work in there.

Thanks,

 

[Burger]

I should have added, the garage is pretty well insulated. Probably the only weak spot being the doors. The rest of it is boarded with insulation between the plaster board and walls. It also has a ceiling with loft insulation above. The floor is 8 inch thick screed. The doors though, which I made myself, could certainly be improved.

Regards,

 

[kwakdonut]

The lower the humidity, the better. So maybe a dehumidifier is the way to go then?

 

[Will]

Without wanting to get too scientific, if the humidity is being reduced from 80%+ to 40%, the moisture must be going somewhere

If you're not collecting it by way of controlled condensation in a de-humidifier, I'm guessing there must be a fair bit of draughtiness in there - where else is the water going?

 

[jaymanek]

http://www.mbclub.co.uk/forums/ot-off-topic-forums/62190-garage-heating.html

here was my thread... cant believe almost 2 years have passed..

 

[Ted]

I use a (very) small dehumidifier and empty the container once a week. As others have said, this will also put a small amount of heat into the air helping to reduce actual condensation.

One caveat is that dehumidifiers become less efficient as the temperature reduces, and I have found mine to be frozen a number of times as the temperature approaches freezing.

 

[JohnDeere8530]

dehumidifier is v important, heat less so, draughts even less so.

Get rid of the water first, there is little benefit to a car being in a heated (dry garage) assuming the temp is above zero. I heat mine a little to make sure it never reaches zero and less temp fluctuations between night and

 

[Burger]

I'm certain that however well insulated the weak point in my garage is the doors. Both the main doors and the side door (it's a detached garage). So as for moisture and heat escaping, that's where it will be going.

I've read the previous thread and the comments here and it seems to me the best solution is to dehumidify and keep the temperature constant and above freezing. I think I understand the issues with condensation but that's where the dehumidifier should come into play right? I also believe that's where having a few draughts, even though increasing the heating bill will actually provide a benefit.

As I said above, I rarely, unless there's no alternative put any vehicle in the garage when it's wet. When it's just a matter of rain, but above freezing, I would probably leave a car outside until the rain has stopped. I also nearly always, depending on the time of arrival home of course, rinse any muck off and leather down the exposed parts, before putting it away. Paranoid? Maybe... but I haven't seen any salt corrosion or anything other than surface rust on exposed metal develop on any vehicle I've owned in recent years.

Mind you, this is my first Mercedes

 

[Mr E]

Without any form of heating the humidity in there is frequently reported as 80%+. Heating it reduces this to around 40%.

A common misconception about relative humidity is that it remains a constant measure - whereas air has the capacity to "hold" more water at higher temperatures.

For example, at about 15 deg C the dew point (100% relative humidity) will be at 10g water per kg air. Raising the temperature by 10 deg to 25 deg C doubles the amount of water that can be "held" in the air. So if the actual humidity remains at 10g/kg air, then the relative humidity (which is what will be recorded by your instrument) will reduce to 50%.

So heating has not reduced the amount of water in the atmosphere in your garage. It could actual encourage corrosion by raising the water capacity of the atmosphere and then allowing the water "held" to condense on cold spots in the garage.

 

[kwakdonut]

I'm certain that however well insulated the weak point in my garage is the doors. Both the main doors and the side door (it's a detached garage). So as for moisture and heat escaping, that's where it will be going.

I've read the previous thread and the comments here and it seems to me the best solution is to dehumidify and keep the temperature constant and above freezing. I think I understand the issues with condensation but that's where the dehumidifier should come into play right? I also believe that's where having a few draughts, even though increasing the heating bill will actually provide a benefit.

As I said above, I rarely, unless there's no alternative put any vehicle in the garage when it's wet. When it's just a matter of rain, but above freezing, I would probably leave a car outside until the rain has stopped. I also nearly always, depending on the time of arrival home of course, rinse any muck off and leather down the exposed parts, before putting it away. Paranoid? Maybe... but I haven't seen any salt corrosion or anything other than surface rust on exposed metal develop on any vehicle I've owned in recent years.

Mind you, this is my first Mercedes

You might dry the upper parts of the car but the underside? That's where it remains damp and the rot starts!

 

[219]

Ettore Bugatti once said , in response to a customer complaining about his car being difficult to start on cold mornings -

" A GENTLEMAN should keep his car in a heated motor-house " !