Condensation

[Jymmm]

Hi all,

 

Has anyone solved or vastly improved the garage condensation issues that plague detached garages/workshops this time of year. 

 

Is it just a case of improving ventilation until the problem goes away?  I have vented eaves and ridge which means the boarded out roof space has very little condensation. But at floor level the tools, bikes, engine parts etc are all dripping. 

[Roger440]

If you want to do it right, seal it up, insulate as much as you can and get a dessicant based hehumidifier.

[Roundtuit]

Maybe put a small fan at ground level to get some more air flow, and maybe use one of those absorbant things that are used for shipping containers to take up the excess.

[MJNewton]

2 hours ago, Jymmm said:

But at floor level the tools, bikes, engine parts etc are all dripping.

 

Is it like that every year? If just this year then I'd put it down to the extreme weather change we've just gone through: low humidity and sub-zero to high humidity and 10+ degrees within 24 hrs or so. It'll take a while for most garages (and more importantly their contents) to catch up temperature wise and so condensation is highly likely in the meantime.

Edited December 20, 2022 by MJNewton

[Marvin]

Is all the floor sealed against moisture? DPC or garage paint?

[markc]

Temperature swings in a garage or shed along with prolonged periods of closed doors makes condensation inevitably. I keep two oil filled heaters on thermostats in my garage to protect my lathe, milling machine and big table saw.

[Jymmm]

The dew point was 11degC yesterday with the previous week more or less constantly below 0 so it’s an extreme shift. 
 

There is a DPC and the floor beam & block + screed is sealed with epoxy. 
 

it’s just difficult to know which way to go. Vent or seal it up. 
 

cars are parked in it too.

 

do piv systems work in this situation ? 

[Dave Jones]

with no insulation your better off venting.

[Temp]

Where is the water vapour coming from? You putting wet car in there?

[Jymmm]

Yes a wet car will inevitably be put in there as the car charger is inside the garage.

 

 

[Radian]

On 20/12/2022 at 06:43, markc said:

Temperature swings in a garage or shed along with prolonged periods of closed doors makes condensation inevitably. I keep two oil filled heaters on thermostats in my garage to protect my lathe, milling machine and big table saw.

Do you think that's likely to be more energy efficient than dehumidification?

[markc]

17 hours ago, Radian said:

Do you think that's likely to be more energy efficient than dehumidification?

I really don’t know, I ask myself this question regularly. The heat stops condensation and makes it more comfortable but yes the vapour is still there, dehumidifiers would also generate heat … 

[SteamyTea]

SHC of water is 4.18 kJ/kg.K

Fusion is 334 kJ/kg

 

Air pressure will make a difference, but basically, if you have are trying to get the air dry, it takes a lot of energy if the temperature is above 0.01°C

 

[Radian]

56 minutes ago, markc said:

dehumidifiers would also generate heat

Yes, my monitoring shows the refrigerant based ones seem to raise the ambient by about 1^oC but I'm not sure how much of this is due to the 'wet bulb' effect. The ones I have draw about 250W so will contribute some warmth but not a lot. My next one will be a desiccant type as these are more suited to outbuilding use at lower ambient temperatures.