Mold in garage/workshop

[Loadstar]

Why dont you just run the PTAC?

 

[IslandTractor]

If it's thick wear a respirator mask until you get it under control. Some mold spores can be deadly.
Once you've got mold it's almost impossible to TOTALLY get rid of.

Don't exaggerate the risk of mold to health. There are certain circumstances where it can be a real problem (immunocompromised due to cancer therapy etc or severely allergic with asthma for example) but for the vast majority of people it is just an everyday exposure to the environment. You will be exposed to more mold spores while gardening or cutting the grass than in your "moldy" garage.

As others point out, the practical solution is to clean it (chlorox) and then keep the area well ventilated and hopefully dehumidified. Tough in Tidewater during the summer.

 

[s219]

Why dont you just run the PTAC?

The setup is basically a three-bay garage with the end bay walled off to be the workshop (about 340 sq ft). That's where the PTAC unit is, and it is running in there full time right now and dripping plenty of moisture to the outside drain.

The humidifier is running on the other side of the wall, in the two-bay area where we park the cars.

There is a 32" door on the wall separating the workshop and garage, which I can leave open to trade air. I know the PTAC unit wouldn't be able to cool or dehumidify both spaces though, since it was sized just for the workshop. So I am keeping the door closed for now.

What I may do long term, instead of running the PTAC full time in the workshop, is to either get another small dehumidifier for the workshop area, or see if the existing dehumidifier can handle the entire garage+workshop with that door open. Then, I can simply run the PTAC for heating/cooling only when I am working in the shop, as I had planned.

 

[Loadstar]

I wouldn't buy additional equipment unless necessary. Slide the PTAC out and set it on the bench and you have a dehumidifier. You might as well run it and get your cooling out of it. Might just condition the entire space.

 

[Loadstar]

I'll say what I'm getting at differently. I would go with a more permanent solution to the problem. Cheap builders model AC to keep the whole thing conditioned.

 

[s219]

I'll say what I'm getting at differently. I would go with a more permanent solution to the problem. Cheap builders model AC to keep the whole thing conditioned.

I was thinking about that, but it would probably be a real waste to air condition the entire garage 24/7 just to deal with a humidity issue. But I will see how things progress over the next few days with the dehumidifier.

 

[user.69169]

Well now I'd dang sure rely on any information a fellow working as a HVAC technician gave me, after all he probably has a degree in HVAC and ain't smart enough to think outside of that degree that should have been left on the dang thermometer.

He's probably way too smart to know you built yourself an airtight chamber right there on top of wet land that comes dang close to being a lifeboat still in operation or using a piece of poly to suck water out of desert sand. That flippin garage sucks water in all day cause it's airtight! Ever since this country went energy nuts people been building air tight chambers to suck water out of the ground under them and paying millions more in energy dollars to get rid of the water they sucked.

I don't care what some college educated fellow claims, moving air picks up water. That's why Mother Nature sends wind behind a rainstorm to pick her water back up that didn't go into the ground.

 

[Loadstar]

With a dehumidifier you are cooling then heating the air. At least with an AC unit you can cool the space and reject the heat outside.

 

[Loadstar]

Well now I'd dang sure rely on any information a fellow working as a HVAC technician gave me, after all he probably has a degree in HVAC and ain't smart enough to think outside of that degree that should have been left on the dang thermometer.

He's probably way too smart to know you built yourself an airtight chamber right there on top of wet land that comes dang close to being a lifeboat still in operation or using a piece of poly to suck water out of desert sand. That flippin garage sucks water in all day cause it's airtight! Ever since this country went energy nuts people been building air tight chambers to suck water out of the ground under them and paying millions more in energy dollars to get rid of the water they sucked.

I don't care what some college educated fellow claims, moving air picks up water. That's why Mother Nature sends wind behind a rainstorm to pick her water back up that didn't go into the ground.

Mostly correct. Fresh air intake and exhaust would probably work. Your humidity outside will be different than inside. You can have your garage door open and the humidity will still be different standing inside vs outside.
You can get looser-fresh air ventilation, but the air can only carry so much moisture. You know... Why when it's humid it feels hotter, swamp coolers and cooling towers fall behind.
Or you can get tighter- keep it sealed and go with more permanent equipment.

 

[Sigarms]

Air Conditioning does not necessarily mean you are going to remove moisture, and in some instances, AC can actually add moisture to the environment.

Talk to a HVAC professional about installing a whole house dehumidifier. Depending on where your HVAC system is located at, you can tie in the dehumidifier to treat your living area as well as run a bypass system to treat the garage area on it it's own.

Guys in NC use them as dedicated stand alone units for crawl space issues as well as for mold and they do great jobs for that purpose alone.

These are expensive units with their own compressor/coil and drain, but they're dedicated for removing moisture from the air, not lowering the temperature.

I have one in my house (whole house dehumidifier). Outdoor temperture can be running 90 degrees with 85% RH and my indoor temperature never goes below 78, but it feels like it's 72 running at 39% RH inside. First time I noticed that my indoor temperature can be running hotter than the oustide temperature but it still feels cooler. My wife loves it to boot

If you want to look at bringing fresh air into a residential structure and moisture is a concearn, you want to look at a energy recovery ventalation unit. Ultimately if outdoor temp and humidity is an issue and you want to bring that air inside, you need to treat the outside air before bringing it into a structure, and that's what a ERV does. The whole house dehumidifier however doesn't have to bring in oustide air, and as mentioned, you can run it as a stand alone unit not needing to tie it into your existing ductwork.