DFW Mustang Forums banner

extractor fan for garage

9K views 56 replies 16 participants last post by  Marcus Encinas 
#1 ·
Has anyone done something like this? i want to put an extractor fan in my ceiling to pull the heat out of my garage and either dump outside or into my attic.

first of all.. is dumping into the attic a bad idea? has anyone done something like this before?
 
#5 ·
it is very common in warehouses, pump houses, etc to use mechanical ventilation to remove heat, but you will never get your garage to be cooler than the outside temperature.

Dumping into the attic is a dumb idea, you would be pressurizing the attic and not allowing it to properly ventilate, unless you replaced some fans on the roof. It also might go against code, I am pretty sure dumping your kitchen hood into the attic is against code, but that might only be because it is a kitchen hood.

Chances are you would need several of those 280 CFM fans too.
 
#9 ·
Chances are you would need several of those 280 CFM fans too.
This is correct. That fan was meant to move out odors and light dust. It will not move any significant volume of air.

Question. If you're willing to put a wall mounted fan, why not just put an AC window unit there instead? The power consumption isn't going to be that much different and you will be 1000 times more comfortable than just moving air around and letting your own sweat cool you off...
 
#8 ·
you would still be looking at 110* inside the garage on a 100* day with a fan. You would need twice as much air to get it to 105* inside. If you really wanted to do this, I would look at an axial wall fan and use it as a supply fan to pressureize the garage and only use it when the garage door is open. I think you are looking at about needing 1000 CFM to keep the garage at 10 degrees above the outside conditoins.
 
#14 ·
Ok.

Maybe, just maybe, this could work for you....

This is a portable AC unit. You have to set up a vent line to the outside to get rid of the heat. I have seen these setup to vent up into the attic. I see no reason you couldn't vent up to the attic and out the soffet.. Big Studly may know more..

http://www.costco.com/Browse/Product.aspx?Prodid=11379946&whse=BC&topnav=&browse=&lang=en-US

There are several brands out there, this one was one of the cheap ones at Costco..

Hope this helps..
 
#13 ·
Jewbacca -- You'd have to go with something like this, to really keep it cool in there. Obviously it's not cost effective, and they likely don't make anything small enough to work in your space.

http://www.bigassfans.com/


Honestly, your cheapest option is buying a big floor fan like you'd see in a warehouse, and just pointing it towards where you are working. You'll want the garage door open though. Otherwise you're just moving around stale hot air. With a standard fan blowing, it at least gives you air movement, and the hot air can rise to the top and roll out the door.
 
#15 ·
so more info:)

my computer room has a portable ACunit that vents hot air into the garage.. making it hotter then ambient. Im not so much looking to make the garage cool for when i work in there as to get that hot air out of it.. the garage was the only place i could vent this unit.
 
#23 ·
they make a few other options. Home Depot doesnt stock them but you can get a gable mount attic fan from lowes and its thermostat controlled. they run about 60 bucks. you wont be able to prevent "back draft" but its only going to run when it gets above a certain temp anyways. as long as you have whirly birds, attic fans, or side or soffit vents you should be fine and not have to worry about any back draft. i would buy a couple and mount one over your whirly bird opening or one of the side vents in your attic as well as cut one in for the garage and be done with it. They move about 1320 cfm so make sure that the air does have somewhere to go.

another option is this

http://www.wholehousefan.com/PRODUCTS/HV-1000-DB.html
 
#25 ·
This may sound ghetto but I recently found a way to work in my garage (east facing) all day. I run 3 fans and create sort of a circular....whatever. Anyway....counter clockwise I have a fan pointing towards the back...the back fan points towards the other side and that fan points towards the center of the garage door (if it were closed).

Nice part is it creates air flow through the whole garage, a little sweat and it is like AC. I swear though, in general it makes it easier to stand to be out there. Used to get to the point where I could only stand to work on something for 5-10 minutes before needing another bottle of water and a break. (I'm an office type worker, so not the toughest around) Now I can go a good 30 minutes or so. Lots of sweat, but the airflow makes the sweat do something.
 
#29 · (Edited)
I have one in my home its about 25-30 inches wide at the top of my stairs on the 2nd floor. That bad boy can move some air. Crack a window about 2 inches in each room and the air flows hard through the whole house. i would just let it vent into the attic as it will cause pressure in the attic from all the air being forced in and it will in turn force the air out of the vents in the corners of your roofs peak. It also cools your attic pretty darn well. But no need to run ducts at all thats just a pointless costly nuiscance as the fans are made to be attic dumped. Also that 7 inch fan is a glorified bathroom fan it doesnt have the power or mass for a strong flow. This one will do the job you want


http://www.homedepot.com/webapp/wcs...langId=-1&catalogId=10053&productId=100018252
 
#32 · (Edited)
Here is a post I found on The Texas State Dept. of Energy website.




whole-house fan
--------------------------------------------------------------------------------


A mechanical/electrical device used to pull air out of an interior space; it is usually located in the highest location of a building, in the ceiling, and venting to the attic. A whole house fan is a simple and inexpensive method of cooling a house. The fan draws cool outdoor air inside through open windows and exhausts hot indoor air through the attic to the outside. Running a whole house fan whenever outdoor temperatures are lower than indoor temperatures will cool a house. In summer, the air inside a home is heated during the hot part of the day. During the morning, late evening, and night, the outside air is often cooler and can be used to replace the inside air. Operating the whole house fan at these times will cool interior materials. As daytime temperatures rise, the whole house fan can be turned off. The cool materials (along with ceiling or circulating fans, which create an additional cooling effect) will help keep the interior more comfortable.

A whole house fan can be used as the sole means of cooling or to reduce the need for air conditioning



Here is a Diagram from a texas building code website I found.

 
#36 · (Edited)
Lol, I worked with my father doing HVAC for 7 years before joining the military my friend.

3) He leaves the a/c on, keeps the door between the garage and the house closed. Then the fan can not be used in this application because it then becomes a ventilation fan for the garage and by code, can not be discharged into the attic.


You dont quit understand, There is no code saying doors have to be open or wich rooms have to receive circulation. Its the same as if he had one in his bedroom and closed his door to the rest of his house.

BUT just to show your a complete fucktard and to help you realise that code is not up for interpretation as its meant to be followed as written I contacted The TEXAS STATE BUILDING CODE AND INSPECTIONS OFFICE @ Oak Cliff Municipal Center, 320 E. Jefferson Blvd. Room 118, Dallas, TX 75203 and asked how the code is to be interpreted.

Interpretation as follows:

Mr. McClay,

Thank you for your recent request for information regarding code and procedure for installing a Ceiling mounted fan in your garage. I have reviewed the code as well as spoken to a few of our in-house inspectors as I really can't say this is a question I have been asked before. Now to your answere, Yes you can mount your fan in your garage and allow it to be vented into your attic as long as you do not share an open attic with an ajoining home. Now after review of the type of fan you had linked in your E-Mail I would say that an inspection or permit is also not required for installation unless there is extensive electrical work involved "Wich I am told there is not" or unless it is of personal preference. You would not be in any violation of housing code or ordinance. Now as to your last question it would also not be in violation if you used said fan to remove any smoke build up that may occure while working in said garage as your attics vents will vent said fumes. Mind you I would suggest you use good common sense and caution if using fan for the pourpose of venting toxic fumes as it just does not seem safe. Anymore questions feel free to contact our office anytime.
 
#37 ·
you see, the code IS up for interpretation because what he suggested could be interpreted as violating the code by some people. Is statement is in direct contrast to other sections in the code. Refer to the secition, directly out of the Residental Code, you can not directly exhaust into the attic with anything except a whole-house ventilation-type fan, if it was being used for ventilation of the garage, than it is not being used for the whole house, unless you did one of the stupid options I listed. Not only that, but the code also prohibits using air from the garage as return air, there is a reason for that, so why push it back into your house through the attic? Makes a lot of sense to a complete fucking dolt like yourself I guess.

Regardless of the code issues, that 7 hears of brazing copper pipes and charging HVAC systems didn't give you any knowledge of why installing that fan is a horrible idea, which I explained twice, yet you didn't get it. Yeah, you win on the code issue, congratulations, you happen to interpret the residential code the same as some other people, but you are 100% off base on that being a good idea.

Stick to toating around guns in the desert, installing residential HVAC units and misspelling quite several fucking times, because that is all you are qualified to do, quit giving shitty adivce on things you know nothing about. You have no idea what effects installing a high powered fan basically inside the house would do because if you did, you would realize what a moron you are.
 
#39 ·
I have this setup in my garage, I have both an AC vent from the house and a 14" fan mounted in the ceiling with a self closing vent, I have it vented to a 14" insulated hose that goes to a roof mounted turtle back. I crack my garage door about 3-4 inches and kick it on and it circulates the air through the garage. It works very well and does not pull any air from the inside of the home. I have been painting and using carb and brake clean and in the garage and before this was put in the wife screamed like crazy from the fumes in the house. I was going to vent in straight into the attick but I figured it was not good to pass the fumes from the chemicals in the garage through my attick in hopes it would all vent out. I had a sheetmetal company make me a flat plate with 14" circle about 6 inches tall and hung that from the roof under the turtle back vent, and had them make a box with the same circle for the fan and vent. I got the vent at grainger.

Total cost for everything was about 200.00, the fan and turtle back were the combo deal you get at home depot for around 80-100.
 
#46 ·
Big Studly, I see what you are saying but you are being very myopic in your argument and I think that you are just sticking to it now because you are so far entrenched.

Of course the whole house fan would be stupid to use when the outside air is hotter than your desired indoor temp, but as already said, the idea is to use it when outside temps are cooler than your desired indoor temp. With the exception of the hottest 2 - 3 months you could actually get a lot of use out of it. Without that type of alternative I have to run my AC for 2-3 extra months per year where I could use the fan instead, which surely draws much less electricty.

As for the garage, it may still be a benefit in the heat of the summer, especially early in the day and into the evening. My garage is probably 90+ degrees right now while the outside air is 81. I can open my garage door but that doesn't bring very much air in without help. If I had one of those fans in the ceiling it would draw the air in and cool the garage down. That is even true if it is 105 outside during the day because during that time the garage is probably 110 plus. If anything it will create some airflow as opposed to no breeze (kind of like what Ceyko was saying he does with fans). In any case I can only see it as an improvement over doing nothing.

BTW, I wouldn't use one of the fans in my house only because I have a high efficiency AC system and dirt cheap electricty cost. :p It's going to be 72 degrees all summer with a monthly electricty bill under $200! :D

I like the idea for the garage though.
 
#48 ·
I don't think you do see what I am saying. My first suggestion was to use a wall fan in the garage, or something that would take the outside air directly into the garage and directly exhaust it outside, yes it would have a benefit. It still wouldn't be comfortable, but it would be a benefit. Where the argument started was to just put it in the ceiling and let it blow into the attic. There is no way to tell the repercussions of that. You would be drawing air from your house, blowing possibly contaminated air into your attic to be drawn back into the house since it is at a negative pressure, etc. Do you really think it is a good idea to draw air from inside your house to the hot ass garage, only to have it made back up by contaminated garage air, or 100+ degree air? I say 100+ degree air because he is probably going to want to use the garage in the summer.

Now to your numbers, a 9 degree difference and a 5 degree difference? The garage will NEVER get cooler than the outside air, so the actual temperature difference you would feel would be less than 9 degrees and 5 degrees respectfully. Is it really worth the cost and effort for that? Go ahead and say you can get the breeze effect from the fans....you can also do that with a $50 floor fan from Wal Mart.
 
#56 ·
Iv looked into putting an a/c unit in my shop and cant justify the cost. Iv got a small metal shop fan I tote around in my shop and point it where ever Im working. Even when my shop is 115-120 I dont break much of a sweat witht he fan pointed directly at me. I realize it would be easier to have an a/c unit keep the garage cool but I look at the money it would cost me for an a/c unit(and insulating the leaky ass shop) and think of other things I could buy with that money.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top