A DIY de-humidifier for a garage and cheap to run - comments

[men8ifr]

I've got metal rusting in the garage so obviously it's water condensing on the cold metal.

After reading quite a bit on here I was wondering about a plan....

What about if I placed a number of metal tubes outside the garage then wired a fan inside the garage to circulate air through the tubes switched by a humidistat.

Basically I've made a de-humidifier but will only work when the air outside is cooler than the garage so the steel tubes are cooler than the air (and the moisture will condense on them).

I guess this will work on a night/evening as the air outside (and hence tha tubes) will be cooler than the air inside the garage (due to the insulation) but I'm not sure about say early on a morning when the sun starts to warm up the air... Though perhaps at that point enough moisture will have been taken out of the air.

This would only work on an insulated garage with no/little ventilation but has the benefot of only having to buy a cheap fan not a de-humidifier and will be a lot cheaper to run since I don't have to power the chiller part of a dehimidifier (which I assume uses most of the electricity)...

 

[Master of None]

Once the fan has blown the air inside the garage into the steel tubes outside. Why are you worrying about the moisture laden air condensing in the tubes. It is then outside the garage any how. Also if the garage has no ventilation the fan will not push any air out. I think a better plan might be to Improve ventilation. Nothing passive drys like a good draught.

 

[men8ifr]

I'm not worried about the water condensing in the tubes outside in fact that's the idea!

Would the problem with a well ventilated garage be that early in a morning when all the metal is very cold the air as it warms up will condensate on the metal and cause it to rust........

 

[JohnD]

it is also useful to cover bare metal in a garage, this also keeps the dust off which accelerates rust amazingly. A cupboard or clean cloth will do.

Many garages have concete floor with no dpm so there is a constant supply of moisture evaporating into the garage. If you lie a piece of plastic on the floor you may see condensation forming under it.

Yes, dew will form inside the garage as the air temperature goes up and down, and the contents temperature lags the change.