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Discussion Starter · #1 ·
I recently moved into a house which will allow me to have a killer HT room. I've got all my electronic components in a closet on a rack with the faces, facing me(finally no more wires!). I'm just worried about heat build up inside the closet, as the Tivo, HTPC and receiver get especially hot.


What I'm thinking is, cut a hole in the ceiling of the closet, and installing an inline duct fan, as seen here: http://www.smarthome.com/3011.html


Will this be enough to create airflow? I'm also worried, as the ceiling above my HT has no crawl space. Or it would, if it didn't have a ton of insulation blown in it. Will the air still get into the attic?


Thanks
 

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Suggest placing a section of duct--say about 7/10 inches long and mounted to a 2x4. Place a temp. cover over the top,before you install it. Then poke a stick up the duct to remove the temp. cover you used. Then your ceiling fan / motor.
 

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Do you have any electronics liquidators in your area? Here's what I did. I know it's a little over the top...


I found a server cabinet with a smoke plexiglass door that manetically seals, with an industrial-strength exhaust fan at the top. Then I built out a cut in the cieling just like you would for stovetop vent and cut it to fit the fan area at the top of the cabinet. Since the cabinet was almost 8 ft tall, this fit perfectly. Then ran a new A/C duct to the closet. The closet stays cool, the equipment stays cool, no problems.


I paid 175.00 for the cabinet, then bought 4 shelves for 25 bucks. It impresses people and keeps my stuff really cool.
 

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You may want to step up to a system intended more for the purpose you suggest. There are a number of in-line "silent" bathroom exhaust systems that have fan's you can mount in the attic and extend a duct down to a vent in the ceiling in your equipment closet and out the roof. Such a system is more in the $200 range for all the various parts.


One place to read about them is HVACquick.com. They have some nice damper grill collars that permit a one way only air flow.
 

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I have a similar closet. My plan is to cut a hole in the drywall at the inside top of one of the walls of the closet, then cut a hole at the bottom on the outside, in the same joist space. I'm going to mount a dual rack fan from Middle Atlantic on that, turned to exhaust air. This will be powered by a MIddle Atlantic fan controller. THe rack itself will have a grill vent at the bottom. My thinking is that I'll draw cool air in from the theater, and draw off the hot air in the top of the closet. The joist space should act as a baffle, keeping down the noise leakage through the rack closet, and keeping the noise from the fans from leaking back into the theater.


The only thing I'm not certain of is whether the MA rack fans will pull enough air out of the closet to keep it cool.


Middle Atlantic Thermal Solutions
 

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There are a lot of different ways to skin this cat.


The only 3 things holding you back are money (budget), the way your house is built around that closet (location, construction, etc), and imagination.


You provide use with some details about the first two, and we can provide plenty of the last one!
 

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Discussion Starter · #7 ·
So far the other options seem a little over the top. I like the idea od the 10in duct with a temorary top to get through the insulation. So far my idea sound the most practical.


I don't want to spend any more than $100, and even that is too much.


The HT room, as well as the house is a peculiarity. Half way through contruction, there were many changes made. The HT room would have been the exterior. As a result, 3 of it's walls are brick, and the back wall, is the back of the house(3 windows, and a sliding patio door, all blacked out). The ceiling is lined with accoustic tile, apparently glued directly to the sheetrock above. The 3 brick walls that face in, are brick, and this provides awsome soundproofing. We cranked some Rob Zombie louder than I would ever listen to it, and it could barely be heard in the bedrooms(just very minor lower frequencies), nothing that would keep anyone awake.


The closet was probably a later addition, as it is in the right corner of the room, and constists of sheetrock and beams. The doors to it, are the folding doubledoors typical of closets, so we removed one door, and the vertical AV-rack fits perfectly in the space!


Here is a floor plan, the @ symbols represent speaker placement. Note: Door A will remain closed at all time, and actually goes into a utility room, which further seperates the HT, adding an airlock kind of deal.
 

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You can pick up in-line bathroom exhaust systems for a lot less than $200 ($50 to $75 range), but they won't be the 'silent' type like BIGmouth mentioned above. In fact they are quite loud. However, if you have a long enough run through an attic before you dump the air outside, even the noisy ones can be made to be fairly silent. Just be careful that you don't run too far since they are only rated for a certain distance and after that the fans can't ovecome the static pressure.


In my next project I have something similar. Behind the theater is a small 3' x 8' projector / equipment room. The projector and equipment stack all ventilate into this room, pulling in cool air from the floor and exhausting hot air near the ceiling. The room itself has a register in the floor allowing cool air to be pulled in from the floor below, and an exhaust fan in the ceiling blowing war air up into the attic. So there are 6 sets of fans and three thermostats:


thermostat placed in equipment rack sealed closet controlling:

- rack intake fans

- rack exhaust fans


thermostat placed in hushbox controlling:

- hushbox intake fans

- hushbox exhast fans


thermostat in ceiling controlling:

- ceiling fan venting to attic

- floor fan pulling in air from below

- damper for each duct running above and below (haven't decided if I'm going to go with electrical dampers or just mechanical 1-way...I might not have enough pressure for the mechanical).


- Rhino
 

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I guess the real question you need to answer is where are you going to move the air to??


I might also suggest using some 120mm computer fans. Your main concern needs to be noise, and you can pick and choose some pretty quiet 120mm fans. You could run them off your current psu in your htpc or you could get a cheapo one and run them off that, or you could get fans that run off of 120v regular power and use those.
 

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I agree about the walls. Curtains or something.


A ducted fan sounds like a good idea as well as other suggestions here. As to your rack, you may want to stack components such that the largest heat producers (amps) are at the top. Heat rises.
 

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You haven't mentioned yet what the foundation is for this room. If it's a crawl space you could take your vent out the bottom. Just run a duct from near the ceiling down the closet back wall and out through the bottom.


If this is slab construction......never mind.


You might also think about removing a brick or two on the side wall and put in a square hooded exhaust vent cover as the way to get the air out.
 

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Have you thought of installing a small round duct on the top that is in line with your HVAC either return or supply or both?
 

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Discussion Starter · #14 ·
It is a slab foundation.


The duct fan is the most practical for this reason. I first went into the ceiling to see about running wire. Problem is, the space above the HT room is maybe 3 ft tall, and the insualtion rises 2 1/2ft, allowing for less than half a foot of breathing space, not to mention this being Texas, the attic is already so hot, it's hard to breathe. So running a duct that goes above the insualtion, and venting the air to the attic seems the only viable way.
 

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I think I'd wait till January if it were me and I had to go into the attic. Also wonder if you have an attic exhaust fan to keep it less than 100 degrees? They help cut down the AC load in my climate, not sure if they are good for Texas?
 

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I am dealing with the same thing. My plans are to have the option of installing vents with fans at the top of the closet and sides of the receiver ... but will run temperature test before cutting into anything as I don't want to go thru unneccesary work. In my experience, attaching fans to metal duct work can be noisy. I have had better luck constructing ducts out of wood or fiberboard and then circulating the air with quiet fans.
 

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Discussion Starter · #17 ·
Thats a thought, what is an acceptable temprature in the closet? I'll measure it now and see how much it needs to be cooled.


BTW, the reciever, HTPC and Tivo are the primary heat producers, they are at the top of the rack. Due to the diffucult access, it would be very difficult to extend the vent to the closet. I guess the question is, will exhausting the air into the attic with a 6 or 8 inch duct fan be enough?
 

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Just an added note, I have one of those duct fans that I bought from Smarthome to boost the air conditioning in an upstairs room. The fan is relatively loud and it is mounted 12 feet from the vents where the air comes out. I would recommend using other fans. Any surplus electronics store will have lots of larger equipment fans and several of these could be used to push and pull the air in and out of your closet. I have a similiar closet and mine is on the ground floor. I plan to cut holes in the floor and filter the cold air from under the house and then exhaust the hotter air back under the house. I'll use some plastic dryer duct to draw the air from the top of the closet down to the fan mounted on the floor of the closet. I also picked up some digital themometers with remote sensors and plan to use those to keep track of what is going on when I initially setup. They will record the min and max temperatures so that you can get a good idea what is going on.

An added thought is that air movement is really the key as it prevents heat buildup right at the equipment.

..Doyle
 

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You will need a path for the exhausted air to go. If you just blow it into a space filled with insulation, that won't help air flow much.


Also where is the air coming from to replace the exhausted air? In normal forced hot air heating systems they have a duct for incoming air and a cold air return so the air moves back to the furnace to be heated again. Following that same idea I would think to improve air flow you would want one duct for blowing hot air out, and another duct to bring cooler air into the closet. If you don't have a duct for cool air coming in, it will probably leak into the equipment closet, but if the closet is tightly sealed then air flow will be poor.


To minimize noise, try moving the fan to the other end of the duct so it pulls air through rather than pushing it. I think that is less efficient, but it does move the noise further away.
 

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Discussion Starter · #20 ·
Hrmmm, well I'll be moving the air into the space above the insulation in the attic. It would help if I could get the fan up on the other end to minimize noise. The closet is not tightly sealed, I figure the air will come in around the electronics sitting on their shelves.


The 6' fan says it's good for 250 cubic feet. The closet can't be anymore than about 110 cubic feet. Will this be enough? As another fan to bring the air in would be a fairly big deal, and noisier.
 
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