Garage humidity?

[BioHazard]

Recently I put a digital hygrometer in the shop and I'm seeing about 75% humidity in the finished area of my shop and around 85+ in the unfinished space.

Is there a general rule of thumb as to what the humidity in a shop should be? 75% seems a little high, but I don't have any noticeable moisture issues. Mainly I'm worried about surface rust on my tools. Anybody run a dehumidifier in your shop?

 

[djjsr]

I had some problems with rust in the past and now make sure the humidity doesn't get above 50%. I don't use a dehumidifier, keep the temp at 50-55 degrees 24/7 in winter and keep the doors closed on humid days in spring and summer.

 

[t. jones]

50% at 50* this morning yes I use a dehumidifier as needed. I saw a show on TV where they said 40% was needed to control rust inside the bridge that links Denmark. They felt moisture control was cheaper than paint!
Thanx Trevor

 

[Titus]

My metal shop is sealed well up high with no vent, but not very well sealed along the bottom. It actually would look like it had rained in the shop on humid days, and I had to deal with rust on a lot of tools. I picked up a dehumidifier from Lowe's on clearance last winter and have it hanging on the wall now with a drain running outside. It is set to come on if humidity in the shop gets over 60% and has done it's job well. I have been very happy with it.

 

[KINGY2]

I also run a dehumidifier direct drain into sink plumbing .

anything to stop mold from starting to grow .

 

[kbs2244]

50 to 60 % is good.
Use a dehumidifer if you need to.
And use a fan to move the air around so it gets to the dehumidfier.

 

[vtx531]

Just make it a walk-in humidor!!

 

[Gizzy]

I use a dehumidifier...makes a huge difference.

 

[nate379]

75% is very high!

40-50% is "ideal".

 

[tncatadjuster]

I started using a dehumidifier last year and feel it is a wise investment for about $1.00 per day. If you want I will look up the model, it was recommended by a friend. It keeps things nice and dry in that end of the shop.

 

[OldCarGuy]

The combination of constant temperature along, air movement, and keeping the humidity between 40 and 50% is the key to combat corrosion. Particularly when storing antique cars and in machine shops. Like most parts of the country, Ohio's weather dictates the use of a good dehumidifier. Each of my garages has a combination forced air furnace air conditioner. Along with a 50 pint dehumidifier. That's mounted on a shelf next to the furnace. They have a humidistat and I leave them running year round. To eliminate dumping the reservoir, I have the condensate connected directly to a drain...

 

[BioHazard]

Alright, now I don't understand why the humidity is so high in my shop. Outdoor humidity this time of year might be 60-90%+. I brought my hygrometer home, the humidity in my house is about 55%. The humidity in my garage is about 60%. I do not have any kind of dehumidifier, only natural gas forced air heat.

My shop is a few miles away. It's like an above ground basement. Concrete, and lots of it. My little electric heater keeps it at about 50 degrees in there. The humidity is 75%+.

WHY?! The only moisture I've ever seen in there comes out of the sink. The roof doesn't leak, and I've never, ever seen any condensation or moisture on the slab or concrete block walls. The walls are painted with latex paint, so I think it would be obvious if any water was coming in. I have not opened my roll up door to bring a vehicle in for months.

A dehumidifier would be great, but I don't particularly like the electricity cost. I don't understand how my house and attached garage stays at around 55%, but the shop 75%? Is there maybe some kind of ventilation problem in my shop?

 

[burleymike]

If the temperature in your shop goes up the humidity will go down. Your house is probably warmer than your shop so the air can hold more moisture. Like others have said the other option is a dehumidifier.

 

[djjsr]

Air leaking in around the roll-up door?

 

[t. jones]

Unless you have sealed combustion your natural gas furnace may introduce moisture. A fridge if routed to a drain is also a dehumidifier. ...Thanx Trevor

 

[James2]

How big of a shop are you all using the humidifier in? Or how big of a humidifier would I need for a 40x40x12 or 40x80x12 shop? I am planning to build a wood frame, finished with drywall and ceiling. Humidity here can be high, it was just raining here and the online weather sites indicate 84% relative humidity at the moment, with 63* temperature... I don't have any heater in the shop but it won't get below 60* here, and won't get above 85*. I have lots of bare steel in my shop...