Computer Closet Venting Ideas [IMAGES ATTACHED]

[Fmstrat]

Hi all,

I'm setting up a 2nd floor office, and will be using the closet for equipment. Obviously cooling is a required element, and I'm thinking of building a venting system that uses outside air in the attic over the garage and air from the downstairs dining room. Here's the plan thus far:

The Closet
4" pipe going out into the attic over the garage. Standard house A/C venting used to link to the dining room.

In the Summer
A box is built with a fan that turns on at 85 degrees. During summer, the box is placed in front of the attic vent, and sucks air out. Pressure differential would pull cool air from downstairs.

In the Winter
The box is moved to the indoor vent. This pulls cool air in from outside and pushes the hot air back into the house downstairs.

Thoughts?


Thanks,
Ben

 

[Deleted member 88227]

Um.... If the office has an AC vent/duct in the ceiling, why not just go up there, "T" off that and put a vent at the top of the closet.

The only problem I see is the thermostat being located else where.

 

[dragonstongue]

I would put that fan at an up wards angle not sure how to word this but to have a longer slant like looking at side of a hill, so you can have said fan lower in the closet it has less to move and makes it easier to move therefore more airflow.

Seems like it will work well, however unless said closet is sealed it will be pulling air from everywhere not just the instream of cooler air from downstairs as you put it

 

[Fmstrat]

Um.... If the office has an AC vent/duct in the ceiling, why not just go up there, "T" off that and put a vent at the top of the closet.

The only problem I see is the thermostat being located else where.

I had thought about tying into the AC system, but there were a couple reasons I didn't think that would be best. First, the thermostat problem, and second, no return duct. One aspect is keeping the heat contained and away from the room the closet is in. If an AC vent comes in, the air needs to stay there, vs. cold air leaking to the outside or hot air leaking in. There's just no control without a return.

I would put that fan at an up wards angle not sure how to word this but to have a longer slant like looking at side of a hill, so you can have said fan lower in the closet it has less to move and makes it easier to move therefore more airflow.

Seems like it will work well, however unless said closet is sealed it will be pulling air from everywhere not just the instream of cooler air from downstairs as you put it

I think I get what you mean. So take the top of the box, cut it at a 20ish degree angle, and place the fan on the angle so the air doesn't have to turn that 90 degrees. Good idea. Also, totally understand the sealing requirements. If there is a small amount of air leak between the room and closet I won't be that concerned as I'll put a "plug" on the outside line in the summer so air only leaves when the fan is running.

Thanks everyone!
Ben

 

[Deleted member 88227]

I had thought about tying into the AC system, but there were a couple reasons I didn't think that would be best. First, the thermostat problem, and second, no return duct. One aspect is keeping the heat contained and away from the room the closet is in. If an AC vent comes in, the air needs to stay there, vs. cold air leaking to the outside or hot air leaking in. There's just no control without a return.

That is how your AC system in your house works. It doesn't exhaust the heat outside (well it does, but not directly like you are trying to do with your setup)

It uses the same air, sucks the air in (probably in a hallway in the middle of the house) cools it, then spits it back out.

Ultimately, you'll want to do the same in that closet. So you'll want/need to leave vents/air holes in the door so air can be blown out into the room.

Though after thinking about it a little more, even your method will cost more money on your electric bill just because it's sucking your cold air and blowing it outside. That's equivalently to leaving a door open, window open or not having enough insulation.

What you could do is just modify a window unit to fit inside that closet. Since you have an "outside" wall where you intend to exhaust hot air out, just cut a hole big enough to put a window ac unit in it, get one with a thermostat.

 

[Fmstrat]

That is how your AC system in your house works. It doesn't exhaust the heat outside (well it does, but not directly like you are trying to do with your setup)

It uses the same air, sucks the air in (probably in a hallway in the middle of the house) cools it, then spits it back out.

Ultimately, you'll want to do the same in that closet. So you'll want/need to leave vents/air holes in the door so air can be blown out into the room.

Though after thinking about it a little more, even your method will cost more money on your electric bill just because it's sucking your cold air and blowing it outside. That's equivalently to leaving a door open, window open or not having enough insulation.

What you could do is just modify a window unit to fit inside that closet. Since you have an "outside" wall where you intend to exhaust hot air out, just cut a hole big enough to put a window ac unit in it, get one with a thermostat.

Hmm, I'm guessing you live in the south?

I'm up north, and if I set the fan to vent air over 85 degrees to the outside, the AC will pull alternate air in through cracks in the house from the outside, which during a large part of the summer is less than 85 except for a few hours a day.

That being said, I had considered running a separate "return" into the hallway for that month of the year when it is warmer out.

Thanks,
Ben

 

[dragonstongue]

if the closet is sealed(many ways to do this) you have one main intake and one exhaust, in which case the air coming that is cold will be heated up and be sucked out via that one fan, you more then likely will have more air leaving then coming in which is fine but at cold air expands it occupies more volume http://galileo.phys.virginia.edu/classes/152.mf1i.spring02/ThermProps.htm

Anyways point being if closet is sealed well enough "losing" the exhaust air outside will not matter near as much as A) there will be more leaving under more pressure then the air coming in and B) there is no other route for this air to go, so unless this cold air was the main intake for the house as a whole it will not matter all that very much, thinking the fact that you have house that has x volume of cool air being pumped in will far outweigh the closet which has x air being pumped out at a warmer temperature, this should also make it slightly easier on the AC as it no longer has to actively deal with the heat the tower is generating it is more passively dealing with it(the warmer air is rising, this air is sucked into closet and given a better route to exhaust)

Personally I think it is an excellent concept, I know a lot of folks that have pumped AC air directly into their computer as it takes longer for that heat to effect the room then it would for the heat of same system blowing into the room and the AC having to cool room + the extra heat which now takes longer to wick away and forces AC to stay on for longer periods of time(I even noticed this when I was using my AC, better when actively sucked into case vs case passively sucking air from room)

Anyways something to try, and hope this made some sense all in all, best of luck