Axiom Home Page Forums General Discussion Home Theater Cooling My A/V Closet

I'm really enjoying having everything out of the way in my new A/V closet, but at the same time, it appears the room is turning into a private sauna for my equipment. With the door open, I hear my PS3 raging while playing, but the equipment at least gets some cooler air circulated in... while the door is closed, I can't hear the equipment, but the room bakes.

There is unfortunately not ventilation to the closet, so short of cutting and running another A/C duct into the little closet (4x3x9), does anyone have any ideas for dealing with the heat build up?

Thanks folks.

Jason

Hmmm... some discussion in this thread:
http://www.avsforum.com/avs-vb/showthread.php?t=772637

I don't know if their are any solid answers in there though.

Is there an attic above your closet? perhaps you can install a small attic fan in the ceiling.

The only thing I can think of is a cooling fan(s) mounted somewhere to either move air around the equipment or out of the room and preferably both, possibly one mounted in the ceiling of the room to suck the air out of the room and through the attic, like a bathroom fan. I guess a fan could just be mounted above the doorway and push the air into the other room. Maybe modifying a PC water cooling kit to run around the rack?

The vent fan into the attic is a good idea, I hadn't thought of that. It's a bit more construction than I want to do, but I may have to give in at some point and do it. I think I once saw some custom doors that had an input/output vent fan built into it (that looked decent too). If I find that I'll post a link here... I remember it being $$$.

Just get a keyhole saw and cut a hole in the ceiling, and install a ceiling bathroom fan... prolly need someone to do the wiring though (unless your closet has a light up at the top you could prolly rig it up to the light switch-

you could even try to install some type of vent in the wall to help circulate air:
http://www.lowes.com/lowes/lkn?action=productDetail&productId=14549-835-531025&lpage=none

just depneds on how much $ and how much work you want to put into it.

For anyone interested... this was what I was thinking of... it's not a full door, just a louvered vent that you put into your existing door... For $250, I'm leaning towards the fan option.

http://www.rackmounts.com/asp/show_detail.asp?sku=DF3466&PiID=1969885&refid=FR105-DF3466_1969885

Thanks terzaghi... researching now. A wall vent looks like a good option. I will probably have to get some help with the electrical because the light in the ceiling is at a place where I couldn't get into the attic from above to finish the installation. Fortunately, the closet also backs directly to another attic space so cutting a hole there and venting to that attic should be rather simple other than doing the wiring.

I've been wanting to get a power cord run to that attic anyway for lighting in the attic, so now I can have a couple of things done at once.

Like Jakewash said, I think some type of vent to get room into the air along with some type of attic fan would be the best combination.

Maybe your closet backs up to another room that you could put the wall vent on so that you don't hear your components whil ein the theater room?

The photo above is a quick shot of the soundbooth I built a few years ago.

I cut three holes in a solid core door, one for a double-pane "window" I created and two for vents that I picked up at Home Depot. The idea is that if the soundbooth gets warm, hotter air can escape through the upper vent, naturally pulling in the cooler air from the bottom vent. I bought some white magnetic sheets from a hobby store and cut them to size to block the vents when they're not needed. They just hold themselves to the metal vents when placed.

In your case, I could see doing something similar for your equipment closet. A window would allow the equipment to be seen if you wish, as well as allow IR remote use. A vent on the bottom that would draw air in from a quiet bathroom fan in the ceiling would work very well. The switch, of course, could be mounted outside the closet or the fan could be temp controlled to power on when the temp reaches a certain point.

I would probably add a fan within the closet to circulate air. This way, you would not have to worry about whether or not the "air path" from the bottom vent to the upper fan is exactly in-line with the heat-generating eqpt..... the air with would be gently circulated while moving through the closet bottom-to-top.

Jason, you wouldn't want to vent directly into the attic unless you are in a warm area in the world otherwise the condensation(warm and cold air mixing creates the condensation) build up would destroy the roof. The fan would have to be vented outside like bathroom fans usually are.

Panasonic makes really great and quiet bathroom-type fans.

I like Mark's idea.

Crap, I said that out loud, didn't I?

Neener-Neener.

You owe me a dinner at the Olive Garden and a can of Old Milwaukee.

I can recommend the portobello mushroom ravioli and chocolate chip cheesecake.

I do live in Austin, TX... where it's hotter than he$$ most of the year, but it gets cold enough for part of the year for me to worry about the condensation issue.

Cutting a hole in a wall - no problem for my carpentry skills ("Carpentry" being very loosely defined), cutting a hole in the roof however is probably beyond me.

I'd have to sell the wife on cutting vent holes in the door... not sure if I'm going to win that argument. Lots of good ideas here though, now I have some options to consider. Thanks all.

Whatever you do, remember that the idea is to draw hot air out rather than blow cool air in. For this to be effective you need a second opening which will allow cooler air to be drawn in as the hotter air is expelled. Cold air is heavier than hot air. So, an intake opening near the floor allowing cooler air in, and a fan near, or in, the ceiling to expel the hot air would work best.

I'm considering just putting the fan right above the rack in the wall which is where all the heat is generated and blowing it out into the attic... The condensation thing has me a little worried though. It's cold so rarely here that I don't think that'd be an issue, but I don't want to rot my roof out over this project!

As far as the cool air intake, I haven't solved that yet... There is an opening under the door (about 1/4 of an inch)... I imagine that's not going to be enough, though with one fan actively sucking air out, that's the only other input source for air... so, would that work?

I don't think you ave much to worry about in your neck of the woods so far as moisture build up i the attic like I do up here.

If it were me, I'd like to see a larger opening of some sort. A larger opening would speed the process of replacing warm air with cooler air. Though not ideal, the 1/4 inch x 2 or 3 feet opening just might be enough. Try it to see. I'm not a physics genius, but I think, as long as there is some way of replacing the air being drawn out, you'll achieve the goal.

The stars appear to be aligning... I ran into a good buddy of mine tonight, told him about my heat problems in the closet and he told me he has a client (he's an accountant) whom he knows well that does A/C duct work. Looks like I have a trusted contractor to at least talk to about the project. I want to see how much it's going to cost to do this the right way, maybe with an A/C duct in and a vent out to the roof.

I don't expect I'll do this immediately, but definitely before the 110 degree Summer weather hits in Austin.

One thing to keep in mind is that any dust hanging out by the floor of the door will be sucked up and into the closet by the exhaust fan. If you do put in a vent, leave room for a filter on the rear of the vent to catch the dust.

As an engineer, I have to ask the obvious question. Why don't you eliminate the closet?

A sentence that starts with "As an engineer" doesn't tend to end well, does it?

Not sure if the 'eliminate' suggestion was serious or in jest, but I don't want all of my components visible in the room, and some of them throw off a ridiculous amount of light and noise, so keeping the door there serves a function of isolating both to the closet (with the heat unfortunately) from the viewing area.

What is behind the closet and to either side of it behind the wall?

Good question... I had to go look myself.



When you walk into the closet, the wall you are facing backs to a guest room wall. The left wall I'm not as sure about. I think it is an interior wall with some 'dead space' (maybe 2-3') in the house between where the bathroom ends and that closet begins.

What did you have in mind?

Unfortunately, I now have a VERY clear picture of exactly what is behind the wall that you asked about... Answer: A shower... with a leak... yes, water has slowly been seeping out of the shower and into the walls, floor, etc. for the last two weeks (it's a new house and the leak didn't make itself known until we had visitors here using the shower).

So... we now have huge holes cut in the floor/wall/ceiling and I had to disassemble the entire rack and empty the closet. No music/movies for the last 3 days...

In any case, it's in recovery mode now (water remediation company has been drying it for days and monitoring for mold, etc.)... rather than mix my actual question with this sob story, I'll post that in a separate thread in case anyone got bored with this post and stopped reading long ago.

Better you found that leak now, then after everything got installed and possibly damaged!

For those of you still with me, thanks.

After complaining as to what a total disaster this has been, I've managed to twist the builder's arm into installing a bathroom vent in the closet to deal with the heat. When the electrical guy came today to run the wiring for the vent, he strongly recommended against the vent, saying that he'd done this for a couple of his friends in their A/V closets and didn't think that the vent would do any good because it's going to be pulling hot air from the closet into an attic that is likely going to be filled with even hotter air. (for much of the year in TX anyway) In fact, he seemed to be worried that hot air from the attic could actually seep back through the fan opening into the closet, which seems like a valid concern.

He did come up with a good recommendation though as we looked at our closet, which was to cut a pass-through vent to the lower right of the closet door above the baseboard (see the picture below). We'll put registers on both sides to make it look like an A/C vent, and in the position it is in in the room, it should be relatively hidden from the seating area.


The rack sits directly opposite the place where the register will be cut, so hopefully this adds some good airflow into the closet (picture).


The problem I believe is that if I just put in this passive airflow vent, I don't have a good way for the air to get both in and out. I could put a fan inside the closet to circulate the air, which eventually should work its way out of the closet, or, going against the advice of the electrician (note, not an HVAC guy), I could also have the builder install the bathroom fan on the right wall to suck the hot air into the attic.

I need to decide by late tonight so I can go get the fan by tomorrow if I want them to put it in. They're doing it at no cost, so my only risk is if I'm somehow going to do myself more harm than good by putting the fan into the wall. I found a 70 CFM vent fan that is only 1.0 sones... (~40 DB), but now with the passthrough cut in the wall, I suppose there is a risk that this will be noticeably loud even with the door closed... 40db is described as the volume of your refrigerator humming, but the seating is a good 10' away from the vent hole that will be cut and the closet door will remain closed.

Long story short, any advice is appreciated... should I have the builder put the fan in at no cost to me, or should I leave well enough alone and hope that the passive airway (perhaps with a fan in the closet to circulate air) will be effective enough to keep things cool?

Can you locate the vent and the fan at the top of your wall? Heat rises so it will encounter less restriction going up than going down.

Yep, the vent fan (blower) will be at the top of the wall, and the air intake register at the bottom. I'm hoping that this results in the cool air flowing in at the bottom and getting sucked out at the top through the blower. I'm pretty sure this should work, it was just that the electrician was so adamant about it not working that it gave me pause.

Thanks for the response Mojo.

It should work as long as the fan up top is not sucking too hard. If it sucks too hard, it will create an almost direct path from intake to exhaust theeby not cooling the whole space.

I hope it's not too late now but get him to wire in a fan control so that you can experiment with fan speed. Note that you can't just use a light dimmer due to the highly inductive load of the motor.

I think it makes some sense to leave the attic out of the equation.

Would it be possible to have TWO registers IN THE WALL (one at the top and one at the bottom)? Seems to me like you just want to connect the air in the closet to the air in the rest of the house (which - unlike the attic - is probably air conditioned?).

If you paint the registers the same color as the walls or something, you'd probably hardly even notice them. They don't need to be very big.

You could even mount a computer fan or something in the top one. You need the convection out of the closet, but you don't necessarily need to convect the component-heated-air out of the house.

Thanks guys. The electrician is up there installing it now... so I guess we'll have to see how it goes with this setup.

Mojo - good point about sucking the cold air straight out... there are a lot of variables, it looks like to some extent there's no way to anticipate how it's going to work until it's in there.

At least though it's not costing me anything to do it...

Just thought I'd let you all know that in the first test of the new setup tonight, it seems to be working MUCH better. The new fan I installed is not audible at all with the door closed and any sort of audio running in the theater.

More importantly, the PS3 has yet to kick into "jet engine" fan mode (which was audible while watching movies) and the closet it noticeably cooler. So far, so good! The real test will come in the dead of summer and 110 degree heat, but for now, it's a huge improvement.

Thanks to all who responded with suggestions and tips.

Good to hear. So what was your final design?

I have a wireless thermometer system that I got from Radio Shack that has four remote thermometers/transmitters. I use one outside, one in the attic and two in various places among equipment in racks so I can monitor their temp.

It might be interesting to have a base unit in the HT so you can keep an eye on the temp with and without the fan....

Good idea Mark.

Mojo, I'll post some pics this weekend of how the finished system looks. In short, I cut a 10x10 air register vent on the lower right part of the door above, and then put in the active vent on the right side of the closet inside where the wall begins to slope (right at the top of where the equipment rack sits).

Even without the thermometers, the difference is noticeable. The entire closet was easily 90+ degrees before the change. Last night it was barely warmer than the main listening room of the theater. (75-80 degree range)

Glad to hear you were able to come up with a setup that solved the problem. Good job.

Look, everybody, it's Jack! Guess the ambassador's been busy.

Jack who?





Just kidding. Good to see you, Jack!

How quickly they forget.

Well, Jack, you're our resident expert on forgetting things...

To close out this thread, I thought I'd post pictures of the finished solution. Thanks to you all for your suggestions. The final solution was a passive register near the bottom to let cool air in, and an active bathroom fan vent near the top to blow it out.

In an unplanned test, last night while watching a movie, I forgot to turn the fan on in the closet (you can't hear it from my seating area, so it's easy to forget) and about halfway through the movie I could hear the PS3 going into jet engine mode again... Fortunately, the fan was not on, which supports everything said earlier in this thread. You definitely need a way for air to get in as well as out. The single vent is not enough to do the job adequately.

Pics below. Thanks again folks.

Jason

Passive Register


Broan (1.0 sone) bathroom fan in closet above A/V Rack

Jason,

To open this thread , you may want to wire a thermostat in series with the fan wiring. Then you can leave the fan switch on and have it kick in when the temperature exceeds the thermo setting.

For all interested in this thread-
My job is to provide cooling solutions for datacenters. Occassionally we have customers with small wiring closets. The main objective is to provide cool air into the room and remove the hot air to prevent mixing. If you duct the hot air out to the attic or plenum space then you need to make sure that space can either exhaust to the outside or gets returned somehow to your A/C system. If the hot air continually builds up in the attic/plenum then this won't do much but buy you some time.
If you have serious heat issues in a small space, APC makes a ventilation unit that will remove up to 3kW of heat.
http://www.apcc.com/products/family/index.cfm?id=337

Thanks for the comment Leslie. The attic has ridge and soffit vents, so the air should be able to escape the attic as well.

Mojo, at some point I may go that route. For now, I'm done screwing around in my closet for awhile.

Forget what? What were we talking about?