I have a dedicated home theater room that I think needs some kind of vent to help draw out the warm air. Any ideas?

Details...

The room is about 10.5 by 25' with 8' ceilings. The room's HVAC needs are adequate, but because the room is so tight (two foundation exterior walls and two double insulated interior walls, with an exterior-grade door), there isn't alot of air circulation. As such, the room's air gets warm (due to equipment, or lighting), or at the very least, stagnant.

The equipment that most contributes to the warm air is the ceiling-mounted projector, and the A/V receiver; the latter is on an open shelf by itself. It may not be practical to put a fan in the eqipment rack.

My thought is to put a vent fan near the top of the back wall (front = screen), in the wall shared with a semi-finished storage room. A on/off switch could be mounted on the wall in the theater.

Warm air in the storage room isn't a concern, nor is any noise moving through the hole in the wall.

Any ideas on types of fans, particular models of fans, etc? I don't think I want a really powerful fan, just something that will help move the air, and aid with taking some of the heat out.

Thanks

In this picture you can see my vent and attic thermostat on the left there, (the one on the right is just a regular supply) which is connected to an in line duct fan with about 12-15' of flex duct in my mechanical room.
http://i240.photobucket.com/albums/ff231/oman321/DSCN1773.jpg

I don't have a picture of the other end but it is basically one of the fans on this link.
http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&productId=100067594&langId=-1&catalogId=10053&ci_src=14110944&ci_sku=100067594&cm_mmc=shopping-_-googlebase-_-D26X-_-100067594

Once the attic stat hits tempature in turns on and sucks out the air to mech. room. I can't hear it in the HT, but I can hear thru the floor in the kitchen above (which I like cause I know it does kick on). Has worked great since day one to remove the heat caused by the projector.

Your other option would be the panasonic whisper line of bathroom vent fans.
http://www.panasonic.com/business/building-products/ventilation-systems/
You can either put it to switch or stat so it kicks on when it reaches a certain temp.

You didn't tell us if the room has a forced air system with returns and supplies. You might not be getting enough flow through the room.

From reading your post I assume that your HVAC system supplys air for your HT and other areas of your home and that is why you can't use cooling during the heating season. I also think you were trying to say that the room is fine when you are using the air conditioning system. Your problem is during heating season. I assume you have tried just closing the vent in heating season? If that is the case then I would just do as the others suggested and install a thermostatically controlled fan.

You can't remove warm air without replacing it with some other air. If you use a fan to draw out the warm air, what is your plan to bring fresh air in? If your room is "tight", as you say it is, then you must have some source of supply in order for your fan idea to work.

I use a couple of inline bath fans to push/pull fresh air into my room. Both are located in my storage area so to keep down the noise. the "return" runs so that it draws hot air off of my projector.

Thanks for the responses.

The room has two supply vents, but no return (that is sitting in the adjacent room about 6' from the theater's door). The HVAC installer told me that based on whatever calculations they do, the room has a vent/ flow/ air input capacity much greater than it needs. When I heard that, I thought "great, so the room will get plenty cool when the AC is on."

But fror the last few weeks we haven't used the HVAC--autumn with nice outdoor temps--and that is when I realized that the air in the theater gets stagnant. Add to that the warmth caused by plugged in equipment and the lights (when I'm in the room) and I started thinking that I needed someway to move air out of the room, vs just circulating within it.

Plus, I do think the problem is more likely to be in the heating season when warm air is blowing into the room, vs when the AC is on. I have closed the vents, which works, but then we are back to the stagnant air (and therefore, the vent fan

When the door is open, all of this is less of an issue. But I like keeping the pets out of the room most of the time. And of course, when the doors are open, sound escapes...

Filmnut: good point. If there was a vent fan blowing out, new air could come in from the supply vent., it could draw air

Your HVAC guy did you a big disservice because frankly he is ignorant of the HVAC requirements for sound proofed theater space.

A return in another room is unacceptable design given that general practice for a professionally designed Home Theater is a heavy well sealed door.

If you had a return and the door was closed you could just run the HVAC fan to circulate the air even if you don't need heating or cooling. First plan of attack is to see if you can get a dedicated return to this room installed. It can be DIY if you are handy.

If you are still under builders warranty you might have some leverage to get them to fix this problem as it is a design flaw.

As noted, you must have a return in a closed space in order to get a good flow of air. I have a 8" Panasonic fan in my screenwall that pulls air out of my theater.

There is 1 duct (with muffler) in from my hvac system and my hvac has a variable speed fan that runs 24/7.

To suppliment that airflow, I also have a passive 8" duct that brings air into my soffit and then empties out into the theater in the rear of the room. Having the 8" exhaust fan in the front of the room causes air to get pulled into the room through the passive duct. I constructed it so that I could always add another inline fan to the incoming air duct if the flow was insufficient. Right now it seems to work well, but I may add the 2nd fan just to see how much better it flows.

Best of luck.

The HVAC installer told me that based on whatever calculations they do, the room has a vent/ flow/ air input capacity much greater than it needs.

Translation, Buddy we just screwed you over by not putting in a return and I'm going to try to snow you with some technical mumble jumble.

Hmm... Well I'm not sure about putting in a return. I'll ask the builder. Is there a noise (mechanical noise, airflow noise) concern if you have a return is the room?

I think part of Budk's design is doable. That is, at the top front of the left wall (facing the screen), insert a passive duct, and then place the exhaust fan at the back wall. The passive vent links to a home gym room (where I don't want any hardware) and the vent fan is in the utility room, where the fan's presence won't matter...

Is there any real world concern with cutting holes in sound proofed walls? Ie, lessening their soundproofness?

I'll ask the builder. Is there a noise (mechanical noise, airflow noise) concern if you have a return in the room?


Yes if they use un-lined metal duct work and the HVAC unit is nearby. They should use either linacoustic lined ducts or true acoustical flex duct.

Do you hear any mechanical noise out of the supplies? Can you hear the theater out of the supplies in other rooms connected to the same main duct work? Both would indicate a problem that should have been addressed during construction.

Oman,

We have one of the Panasonics in our main bathroom.... while it is fairly quiet.... I don't know if it is quiet enough for the HT setting.... That being said, I am not sure if it is the super quiet one, or just the quiet one, we got it for around $200 IIRC.

I am trying to retrofit a bafflebox to exchange the air in my HT room with the rest of the basement.....

Was the HVAC contractor aware the room was to be insulated and air tight prior to installing the HVAC system?

Honestly, at this point, don't recall if the HVAC contractor was aware of the room's purpose, or the degree to which it was going ot be "sealed" up. At some point he did know, but that might have been after the ducting, returns, etc were already installed.

One plan I have going is to cut the vent hole in the wall shared (theater & utility room) and run a number of feet of acoustic ducting in the ultility room, at the end of which will be the inline fan (a Panny Whisper Quiet In-line fan). This keeps the fan noise away from the theater and is relatively easy and cheap to do. If I need passive flow more than provided by the supply ducts, I can cut one in the other interior wall.

If he knew, he's got a long list of code violations he needs to fix (the length of the list depends on where you live). If he didn't know, you're likely on your own here.

...

One plan I have going is to cut the vent hole in the wall shared (theater & utility room) and run a number of feet of acoustic ducting in the ultility room, at the end of which will be the inline fan (a Panny Whisper Quiet In-line fan). This keeps the fan noise away from the theater and is relatively easy and cheap to do. If I need passive flow more than provided by the supply ducts, I can cut one in the other interior wall.

Resurrecting an old thread...

I'm the owner of a new dedicated home theater. The theater is in its own room (20x21) and has a control room (roughly 12 x 12 but its not a square room) attached to the theater. There is an HVAC air duct in both rooms. This is on the second floor with the attic above the rooms. The return is located outside of both rooms.

The control room connects to the theater through double doors that are closed when we're watching a movie/TV. The control room also runs the TVs (all A/V) throughout the house so something is always on in that room. The double doors are the only way in or out of the control room. The only way to the control room is through the theater.

When the A/C is on (we're in the Houston area, so it is hot here throughout the year) both rooms are great. The A/C provides enough air pressure that the door to the hallway from the theater will close just by the A/C coming on. The flow is more than enough to cool the control room within 20 minutes from any temperature and make that room comfortable. The same is true with the theater room.

My problem, just like the original poster, is that when the A/C is off, the air stagnates. Even at 77 degrees the air feels much warmer in the control room any time the HVAC is off. About 15 minutes after the A/C shuts down the air feels stagnant. Turn the A/C on and everything is good again. The interesting thing is that dropping from 77 to 76 has the same effect as dropping from 72 to 71. Its just having air flow that seems to matter the most.

So, I'm trying to find a solution that doesn't require leaving the A/C on 24 hours a day. A ceiling fan does not have much effect (I think the air flow isn't enough to get out the theater with the ceiling fan). I've thought about a active wall-to-wall ventilation system (from the control room the air would vent over the staircase) but then I have to find a way to have that activate when the HVAC shuts off.

Any ideas? I've thought about putting a return into the control room but then don't I need the HVAC on for that to work? Are there passive vents that would work? With an active vent, I'm not sure how I would set a thermostat since I really would want the fan to come on when the A/C turned off. That is what led me to thinking about a passive vent.

Any help is greatly appreciated.

Rooms below grade often collect humidity and concrete seems to exude a bit of moisture. Not condensation, but you get the idea. It's what makes even a "dry" basement a bid moist.

My theater is in my basement and I have a supply and return and have an in-line fan in each. They run on low speed 24-7. It's the only way to get air circulating into and out of the room. Outside the room I have a de-humidifier do dry air replaces any moist air in the theater.

The only other wild solution would be to have a 5 gallon pail of some desiccant.

Ah, yeah. Look at your T-stat. The fan has two settings: "Auto" and "On". Put it in the "on" position.

Ah, yeah. Look at your T-stat. The fan has two settings: "Auto" and "On". Put it in the "on" position.

That's exactly what I'm trying to avoid doing. Having the HVAC fan run 24/7 throughout the entire second floor of the house would really add to the energy bill. But thanks for the suggestion.

Rooms below grade often collect humidity and concrete seems to exude a bit of moisture. Not condensation, but you get the idea. It's what makes even a "dry" basement a bid moist.

My theater is in my basement and I have a supply and return and have an in-line fan in each. They run on low speed 24-7. It's the only way to get air circulating into and out of the room. Outside the room I have a de-humidifier do dry air replaces any moist air in the theater.

The only other wild solution would be to have a 5 gallon pail of some desiccant.

Ted, that's very interesting. Do you know the model of the in-line fans that you used?

Luckily on the second floor I don't need to worry about humidity too much - particularly when the A/C comes on occationally (which is still my intent).

I hadn't thought about an inline fan. Thank you!

That's exactly what I'm trying to avoid doing. Having the HVAC fan run 24/7 throughout the entire second floor of the house would really add to the energy bill. But thanks for the suggestion.
...and while we're being snooty, first, just run the thing while you're watching a movie. Second, check with a local mechanical engineer (that is "mechanical engineer", not HVAC contractor). In many areas of the country, running the fan all the time reduces, rather increases, energy consumption (and improves indoor air quality).

A couple of other points: Fan "on" doesn't mean the A/C is on. Second, the best bet in Houston (I lived there) is to (a) keep the air circulating and (b) install a whole house dehumidification system. I did. Sweet.

Ted, that's very interesting. Do you know the model of the in-line fans that you used?

FG6XL http://www.fantech.net/fg.htm Exceptional product.

...and while we're being snooty, first, ...

Actually I wasn't trying to be snooty - so, sorry if it sounded like it was.

I was just trying to say that I thought running the fan 24/7 would cost more. However, (as you pointed out) running it just when we're using the room is a good thought. A/C would still kick-in when the temps got higher.

(I wonder if I could find a module to work with the home automation system and control the fan-on from the room?)

Thanks for the suggestion - again sorry if my response sounded different than I intended.

My little assembly is essentially what Dennis suggests. My theater is essentially on its own zone. I simply exchange air with the rest of the cool basement. Above grade, you'd need mechanically cooled air.

My little assembly is essentially what Dennis suggests. My theater is essentially on its own zone. I simply exchange air with the rest of the cool basement. Above grade, you'd need mechanically cooled air.

...or the dehumidification system Dennis mentioned. Very interesting and perfect that it comes on when the AC goes off.

We're running a test right now with just the fan on for the rooms. Unfortunately it doesn't look like URC has a thermostat yet that can be used with the remote system.

Actually I wasn't trying to be snooty - so, sorry if it sounded like it was.
No worries. I was likely low on my meds. (coffee).

:d

As an option for you or someone else reading, my HT had two supplies and no return air vent. With a sealed room, I was worried about stale air collecting, and also worried that the two supply vents could not force air into a sealed room (physics 101).

So I put a Panasonic in line exhaust fan in the next room, and ran flex duct into the HT. The fan pulls stale air out of the HT and dumps it into the main basement room, which has several returns. Scroll down this link to see pics:

http://www.avsforum.com/avs-vb/showthread.php?t=1204821&page=2

Because the fan is in the next room, I don't have to worry about a noisy fan in my HT. The only downside is that it is a potential noise leak, but the flex duct is a 25 foot run, inside an insulated soffit with DD + GG, as per soundproofingcompany's recommendations:

http://www.soundproofingcompany.com/media/cim/spc-soffit-construction.gif

Nice room! I really like the wood columns.

Do you leave the fan running while watching movies? How quick is the cool-down when the fan is on?

Andy

Nice room! I really like the wood columns.

Do you leave the fan running while watching movies? How quick is the cool-down when the fan is on?

Andy

The room is getting painted as we speak, then carpet, still need to hang the projector and screen too. So I can't speak from experience yet. The fan will be hooked into the control4 home automation system so I'll be able to turn it on/off with a button on my remote control. I could also program it with control4 so it turns on whenever the projector is on, I'll be able to test it when I'm moved in.

Had a contractor who specializes in fans (got the company name from Panasonic) look at the theater yesterday. What he would like to do is to install an exhaust vent/fan. The exhaust would be vented to the outside. I'd have an on/off wall switch for the low noise fan.

I'd have to figure out a way to get the URC remotes to control the wall switch, but I believe I know how to do that.

The experiment with turning on the HVAC fan was interesting. It helped but not enough. That led me to believe the air needs to be pulled out of the room, not just circulated.

After 8 months, this is the first item that I've thought I should have put more planning effort into while the house was being built.

Ask your fan expert what that will do to the static pressure and where the replacement air will be coming from...also, how many CFM.

Ask your fan expert what that will do to the static pressure and where the replacement air will be coming from...also, how many CFM.

Dennis, thanks. Yes, he was going to include the CFMs in the estimate. However, the static pressure he did not mention.

For the replacement air, let me try to draw a diagram in TRS-80 format (ASCII characters) - hope this works - it didn't work. But basically the return is in the hallway outside of the theater (on the opposite end of the hallway from the theater). If I understand this right (and please correct me if I don't), the return in the hallway is not pulling much air from the theater and even less from the control room (which is inside the theater and to the back). When A/C is on, then the vents in the theater and control room provide air and that extra pressure is enough to close the theater door to the hallway. When the A/C is off, the air would be pulled in from the hallway through the theater and then to the exhaust vent in the control room. Hallway air is always cooler than the theater / control room, even with A/C off. This would mean I would want to make sure that the theater has a higher pressure than the control room, if I understand this flow correctly.

Other than the static pressure, is there anything else I should ask about?

I would suspect that you will not be getting sufficient replacement air into the room. Basically, if the fan isn't pulling much air, you rather need to wonder why you're doing it. If it does pull enough air, I rather suspect you won't have enough replacement air coming in (but, I'm not there, so this is a guess).