Two Car Garage Ventilation

[simbey1982]

Hello All,

Stumbled upon this forum while googling seems like there is good insight here and I need some on what ventilation setup i should do for my garage.

I have an attached two car garage that is 24' x 24' x 8.5' The walls and ceiling are insulated and its finished with drywall and painted. Concrete slab floor, double uninsulated metal garage door with top row of windows and one 4x3 glass window on exterior wall. Just a space heater for heat when its needed. Unlike many of you on here its your average garage but it suits my needs.

I use it to park two cars in, store some stuff, and do household projects on a workbench. I dont use it for painting, chemical projects, etc just average stuff.

Next bit of info is i live in the pacific northwest. It RAINS CONSTANTLY except for a short 3 month break called summer . What this means is there is always water being brought into the garage on vehicles. This water evaporates and condenses on my garage door and window until they are SOAKING wet. I have stand up fan i use every once and awhile to try and control the humidity but its not ideal because i have to open the window for ventilation and it rains inside. When its nice out i usually just open the door except on really hot days.

So what i would like to do is create some sort of ventilation system through either a timer or dehumidistat. My research has found several all in one solutions that run upwards of $400...i have a hard time believing that a handy guy like me has to spend that much for some ventilation. Also i dont know what kind of CFM i need to move to achieve the dehumidification im looking for.

Any of you that have taken on this project i would love to see your solutions posted here with pictures and the like. I am competent in home improvement and electrical wiring etc so im not afraid to get my hands dirty.

Thanks in advance

Cory

 

[z28toz06]

When you "pull" moisture through a room, you are going to spread it out around the room. It will have a tendency to collect or precpitate where the temperatures differ vastly, i.e. warm vs. cold surfaces.
would you maybe be better off with a dehumidifier? It collects water and can always be used to water plants etc. It is also "distilled" water, that can be used in irons etc.

 

[simbey1982]

What kind of dehumidifier...im guessing its not just a big Dri z Air thing....

 

[Jack Olsen]

A dehumidifier might be the answer.

I don't have a moisture issue, but I needed ventilation for welding and painting in the garage.

I cut a hole in the roof and installed an attic fan I got from Drillspot.

Here's a link to it.

Eighty bucks. Took me a couple of hours to install. It hasn't leaked.

And it ***** the door closed when I turn it on.

Specs:
120V, 1/10 HP
4.3 Amps
1050 RPM
1200 CFM @ 0.030-In. SP
Max. Attic Area (Sq.-Ft.) 1715

I took out the thermostat and ran it through a wall switch, but with the thermostat you can have it run automatically, coming on anywhere from 70 to 130 degrees. I know there is such a thing as humidity switches, but I've got no experience with them.

 

[RossABQ]

Ventrilating will just draw outside air in, which if it is humid will have limited amount of improvement. Dehumidifying will remove the moisture from the air, but infiltration will again limit effectiveness. It sounds like your garage is reasonably tight, so I would go the dehumidifier route. Keep in mind that the typical refrigerated drier adds heat to the room as it's dehumidifying, so you get a bonus there.

 

[simbey1982]

Sounds like dehumidifying is the way to go. Jack I have an attic space so your solution would be a little bit difficult...though i guess with some ducting and a grill on the ceiling it could be done...How loud is the attic fan jack?

Cory

 

[z28toz06]

What kind of dehumidifier...im guessing its not just a big Dri z Air thing....[/QUO

I just bought a frigidaire. It's a nice unit because it will keep on dehumidifying down to 40 degrees farenheit.
http://www.bing.com/shopping/Frigid..."o"+docid="D43D5EE6EB6A8BEF5006"]&wf=Commerce

 

[Jackfre]

I'd suggest looking at www.tjernlund.com. They have recently introduced a product called the Xchanger. It is simple to install and only draws 40 watts. You can change the air direction, either both fans blowing in/ out or one of each. Includes dehumidistat. I've had 4 dehumidifiers over the years. They cost a few hundred, draw alot of current and in my experience don't last more than 2-3 years. They then cost me $25-35 bucks at the dump.

I have represented Tjernlund for the past 20 yrs, so bias noted. They are an excellent American manuf.

 

[RossABQ]

I'd suggest looking at www.tjernlund.com. They have recently introduced a product called the Xchanger. It is simple to install and only draws 40 watts. You can change the air direction, either both fans blowing in/ out or one of each. Includes dehumidistat. I've had 4 dehumidifiers over the years. They cost a few hundred, draw alot of current and in my experience don't last more than 2-3 years. They then cost me $25-35 bucks at the dump.

I have represented Tjernlund for the past 20 yrs, so bias noted. They are an excellent American manuf.

That might work for a basement that is significantly more damp/humid than the outdoors, but a garage is likely to be nearly the same as the outdoors. Ventilation alone will not be completely effective. Something like the Xchanger with a zeolite wheel to remove humidity but conserve heat would be ideal, not use refrigerants, and dehumidify. It will still need to consume energy for drying the zeolite wheel.

 

[simbey1982]

Jackfre I like the idea but my experience with fans isnt great. I have a big one that i run. Takes like 2-3 days to dry it out by air exchange. I would only need to run the dehumidifier during the wet parts of the year....admittedly thats like 3/4 of the year but yeah...Thanks for the input on this...anybody with some experience with dehumidifiers let me know...i think i would like something i could gravity drain or pump drain that can be set to a humidity level.

Cory

 

[simbey1982]

So taking the sage advice from this website I decided a dehumidifier was the way to go. The moisture just needed to be controlled and i didnt really have a need for fume ventilation.

After a bunch of reasearch i found a couple of general rules about dehumidifiers.

1. They ALL break down early and often regardless of brand.
2. They are pretty expensive considering they are just a big sponge.

Anyhow i finally decided on a Soleus CFM-40E 40 pint per day max dehumidifier. The biggest reason i chose it is because it had a lot more positive comments about its longevity than other brands and was a bit cheaper. Other features i like

1. Has a Humidistat that you can set. When the desired humidity is reached the compressor shuts off (the fan keeps running though..whats up with that?)

2. Has a quiet mode that pretty much sounds like a small fan running.

3. External drain that I ran to a drain so i dont have to empty the bucket EVERYDAY (I found even on the lowest setting i was filling up the reservoir once a day.

4. Easy on the eyes.

My garage is now BONE DRY!! no more streams of water running off my garage door when opening and no more mold growing on the walls. This thing is a necessity if you live in a rainy climate and put your cars in the garage. Here are pics of my setup...Hope this helps

 

[Reflections Detailing]

Thanks for the info on the Dihumid unit you got. Can they all be hard plumbed? Why didn't you go with a larger unit for your 2 car..........what is your sqft of the garage?

I only need one in the winter and early spring........snow and heated garage= mold under neath the cabinets.

cheers,
GREG

 

[simbey1982]

575sq feet. The 40 pint is plenty to handle that space. Almost all I looked at had a "continuous drain" which is what you're talking about. This thing is great and it keeps the garage bone dry.

 

[Reflections Detailing]

^^^
Thanks for the reply!

in your researching what should one be looking for........what things don't matter? Where are the best prices?

Cheers,
GREG

 

[simbey1982]

I found that most were the same. There was a DeLonghi that had a pump in it so you could drain without gravity which was cool.

It came down to reliability because the reality is most dehumidifiers aren't reliable. I found that this one was the most reliable of the bunch. Around $200 is about what they cost

Have fun

Cory

 

[Reflections Detailing]

I found that most were the same. There was a DeLonghi that had a pump in it so you could drain without gravity which was cool.

It came down to reliability because the reality is most dehumidifiers aren't reliable. I found that this one was the most reliable of the bunch. Around $200 is about what they cost

Have fun

Cory

So where did you find all the reviews on the various units?

Cheers,
GREG

 

[aafadca]

I'd suggest looking at www.tjernlund.com. They have recently introduced a product called the Xchanger. It is simple to install and only draws 40 watts. You can change the air direction, either both fans blowing in/ out or one of each. Includes dehumidistat. I've had 4 dehumidifiers over the years. They cost a few hundred, draw alot of current and in my experience don't last more than 2-3 years. They then cost me $25-35 bucks at the dump.

I have represented Tjernlund for the past 20 yrs, so bias noted. They are an excellent American manuf.

I checked out the site and it looks pretty interesting but I didn't see any prices. I'm interested in the basement exchanger.

 

[ssathre]

I checked out the site and it looks pretty interesting but I didn't see any prices. I'm interested in the basement exchanger.

there is a "retail" link in the upper right of the page. the unit you are looking at is $279.95.

 

[thrifty bill]

I have a rock house, even the basement foundation is rock. That makes for a very porous (humid) inside. I run one dehumidifier on the main floor and one in the basement.

+1 They tend to last 3 to 4 years max. I've tried several brands.