A room within a garage

[Mr Blah]

I have a couple of my rooms in my garage that I have wall ac units. I installed them last yr and road out the summer with very high temps within the garage. (not in the growrooms)

I want to exhaust the heat from ac's only not the whole room.
I understand I need an inline fan that matches the fan speed of the ac. I will build a box around the very back of the radiator or the ac part that sticks out of the room.
How big should I build the box with the inline fan connected to it?
Also is there a way to turn the exhaust fan on only when the ac kicks on?
Hope this made sense. I've seen another thread with this kind of set up but can't find it.

 

[theother]

I have a couple of my rooms in my garage that I have wall ac units. I installed them last yr and road out the summer with very high temps within the garage. (not in the growrooms)

I want to exhaust the heat from ac's only not the whole room.
I understand I need an inline fan that matches the fan speed of the ac. I will build a box around the very back of the radiator or the ac part that sticks out of the room.
How big should I build the box with the inline fan connected to it?
Also is there a way to turn the exhaust fan on only when the ac kicks on?
Hope this made sense. I've seen another thread with this kind of set up but can't find it.

I will be interested to see what others have to say about this. I have considered it for my veg room in the past. As far as kicking on the fan when the ac comes on it shouldn't be too hard. I assume that these are wall mount units (not inverted compressors) so they can run off an environmental controller (probably with a high wattage relay) Just plug the inline fan ducting the heat into the same outlet that controls the ac. That way when the ac gets power so does the fan.

If you are not using an environmental controller to run the AC's then maybe just get a cheapy thermostat to plug in the ducting fan and set it lower than the threshold for the AC's. If you do it this way you will have to make sure that the thermo for the fan is set a bit lower than the ac.

If this is a super stealth thing you may want to consider using inline carbon filters before or after the fan. Window bangers do not have sealed compressors and you are going to be getting some stank coming out of the exhaust ducting.

 

[Mr Blah]

Thanks theother. I found the link;
https://www.icmag.com/ic/showthread.php?t=95491
They are 12000btu wall ac's and both are about 5' back to back of each other. I am going to make a box about 12" sticking out of the back of the ac and make a 6" hole at the top of each unit than split with a why to exhaust both units on 1 6" 550cfm fan.
No worry about the odor. I am a legal C Giver.

 

[theother]

Thanks theother. I found the link;
https://www.icmag.com/ic/showthread.php?t=95491
They are 12000btu wall ac's and both are about 5' back to back of each other. I am going to make a box about 12" sticking out of the back of the ac and make a 6" hole at the top of each unit than split with a why to exhaust both units on 1 6" 550cfm fan.
No worry about the odor. I am a legal C Giver.

Excellent, can't wait to hear how it turns out. If it works, that would probably be the way I would choose to set up my veg room.

 

[Mr Blah]

Got them installed, come to find out the Active Air 6" fan is only 400cfm. So dividing it for to extractions will only give me 200cfm's for each box.
I don't think it is enough as the ac almost (but doesn't) blows off the box when she turns on.
Got only one ac running now and don't need the other till deep summer so we will wait. If I need to I will up the fan to a 8".
I'll get a picture up in a bit.

 

[theother]

Got them installed, come to find out the Active Air 6" fan is only 400cfm. So dividing it for to extractions will only give me 200cfm's for each box.
I don't think it is enough as the ac almost (but doesn't) blows off the box when she turns on.
Got only one ac running now and don't need the other till deep summer so we will wait. If I need to I will up the fan to a 8".
I'll get a picture up in a bit.

Does the 6" do one unit okay? Do you have anyway of getting a temp inside the box? I would love if this would work. You can get those C.A.P. 6" fans or whatever the other cheap brand is for like $65-$75. Might be best to do one for each ac, and then replace them maybe yearly or whatever. I have a feeling the heat from the ac's is gonna shorten the fans lives. I don't know for a fact or anything, it just seems likely.

 

[Mr Blah]

Does the 6" do one unit okay? Do you have anyway of getting a temp inside the box? I would love if this would work. You can get those C.A.P. 6" fans or whatever the other cheap brand is for like $65-$75. Might be best to do one for each ac, and then replace them maybe yearly or whatever. I have a feeling the heat from the ac's is gonna shorten the fans lives. I don't know for a fact or anything, it just seems likely.

It works but I think I am going to put a small 2" space around the back of the ac so the box is not right up against the back...I know it defeats the purpose of building it...but...something is better than nothing. So letting some of the hot air escape might be better for the unit and for extraction.
I'll revisit the idea when it gets hotter.
6" sounds good for each.
If I had to guess the temp of the air, I'd say in the 90F ish.

 

[Guest101]

Note: 6" ductwork is good for 180 - 200 cfm in the best circumstances.

 

[Jhhnn]

Why not just use an ordinary vent fan to vent the whole garage space?

Depending on construction, you have a lot of alternatives available, probably easier & more effective than the ways you're contemplating.

 

[KushTrees]

^^ I agree that it'd be easier to just vent the space w/ 8'' fan/filter combo, rather than build a box around the a/c's.

 

[Jhhnn]

^^ I agree that it'd be easier to just vent the space w/ 8'' fan/filter combo, rather than build a box around the a/c's.

Not knowing the details of the garage construction, it's hard to be specific. If the garage has an attic space, then fairly large vents can be installed in the gables or under the eaves & the attic insulated from the garage area. Something like this can be installed in the ceiling of the garage-

http://www.wholehousefans.us/benefits.asp

With open windows or vents allowing air to enter the garage space when the fan is on, vents like this-

http://cgproducts.johnsoncontrols.com//MET_PDF/1201678.PDF

Negative air pressure created by the fan pulls them open.

Fixed gable vents-

http://www.lowes.com/pd_18206-835-120061824001_4294858181__?productId=3018447&Ns=p_product_qty_sales_dollar|1&pl=1&currentURL=%3FNs%3Dp_product_qty_sales_dollar|1&facetInfo=

Under eave vents- use several-

http://www.lowes.com/pd_42028-228-E..._product_qty_sales_dollar|1&page=2&facetInfo=

Those are just examples. Done well, garage temps will be reduced to a few degrees above ambient, if that, Solar gain greatly reduced, & the AC unloaded tremendously.

 

[mitygrows]

invest in a mini split I have a room built in my garage and I have a mini split in their best investment I've ever made

 

[Scottish Research]

invest in a mini split I have a room built in my garage and I have a mini split in their best investment I've ever made

You have the whole mini split unit in the garage? Do you just vent the non grow space? I would like to get one of these, but adding another AC outside might draw the wrong attention.

 

[Mr Blah]

I have 4 rooms roughly 9x7x7 with the exception of one being 10' tall. All within a 2 story 40'x24' garage. Occupying the downstairs is the grow. (no I don't use the upstairs for anything except for a play room)
In 2 of the rooms there are 12k ac wall units, the ones talked about in this thread.
I only had 2 6" fans that were doing any extraction out of the grow.
I managed for a yr. It's when I added the last of the 1 out of the 4 rooms is when it became unbearable to grow.
So I added a 12" and a 8" inline fans for two of the rooms and vented outside. (temps dropped from 90F+ to 71F)
At that time I also added the 6" to split into two, exhausting the 2 ac's heat outside, described in this thread. BUT with the 19 degree temp drop I do not need this ac extraction at this time.

I do have a mini split 12K, installed last yr for an attempt to cool the ac's heat without venting outside which I indefinably did.

Sorry for the confusion.

 

[Mr Blah]

The first pic shows/hidden a room on the left (can't see) with a 12" fan exhausting outside. The room on the right is an 18 bucket RDWC venting out of that room and dumping into another room.

The next pic shows a 6" passive starting in the veg room sucking air from cool part of the garage passing over 2-1k cool tubes (vertical) than (where you see) outside.
The left of pic shows the "Y" that I just installed to exhaust the ac's air. The one hooked up is not on because I have an 8" fan in the room exhausting air and it is working good without the ac. The other part of the "Y" you can see it is off of the ac.
The split (not running at this moment) is straight ahead.

Next pic is the "Y" split exhausting outside.

Room A of my flip rooms (12" fan up top) with DIY "Y" and elbow.
4 different strains and in week 6, bare bulbs vertical.