[EricWindow]

I built a 13x16' theater room in my basement. I spent time to sound isolate the room and most sound is transfered via a single HVAC inflow register in the ceiling via flex duct. I live in central NC and weather is normally moderate. The basement is a walk-in type and the basement HVAC unit [a Heat Pump] is separate and does less than the other units. The theater room has all electronics out of it and remoted to an exterior closet except the projector. The problem is heat from 3-6 bodies and the projector causes the room to get too hot. The room as a side effect of soundproofing [including a solid exterior door] is pretty well air sealed. I realize I have to provide a return register in the room but I am not sure that just hooking it into the same HVAC unit would do very much good. The HVAC in the basement rarely runs so the heat just sits there in the room, in winter I even shut off the air vent to limit heating. The work to add a return air duct would be small but may not do much since I do the same thing by cracking the door and that doesn't work too well either. The other option I thought about is to tie into the main level HVAC intake since it works more often and the HVAC unit is located just behind the rear wall of the room. I almost would like to be able to get cold fresh air from outside to the room but that will only help in the winter. This would be possible if I installed a fanned duct through a utility closet next to an exterior wall. But except during the winter, that option has little use. Any ideas what I should do other than a separate unit just for that room? My DIY project was great except this final detail is really stumping me for a proper solution.

 

[NiNe O]

Can you zone the basement unit? This would give you a t-stat in the theater and keep the temp exactly where you want it and keep the unit from heating/cooling areas you deem less important.

http://www.alpinehomeair.com/viewcategory.cfm?categoryID=382

 

[EricWindow]

Maybe but

The room is only about 10% of basement floorspace. Wouldn't that cycle the unit too much? Also how expensive would that be?

 

[NiNe O]

you would have to put other areas onto the theater zone to work proplerly. about 800 bucks in material. If cheap is what you want, tap into the upstairs duct, supply and return. Kick the unit fan on to circulate some air.

 

[EricWindow]

I kinda like the second option

I believe I can easily tap into the fan control for the main level and thermostatically control it, the ducting would be very minimal. Do you think I should condemn the current outflow register or just leave it for when the door is open?

 

[beenthere]

I believe I can easily tap into the fan control for the main level and thermostatically control it, the ducting would be very minimal. Do you think I should condemn the current outflow register or just leave it for when the door is open?

Add a large return from the basement system, and another supply from the basement system. When you are going to use the room, turn the fan to "on" at the thermostat.

Slaving the 2 supplies to the theater room would also be a good idea.

 

[EricWindow]

Putting a large return and a second register would bring the sound out of the room defeating the sound dampening enhancements I spent a lot for. It would work if ventilation was my only consideration.

 

[Technow]

Putting a large return and a second register would bring the sound out of the room defeating the sound dampening enhancements I spent a lot for. It would work if ventilation was my only consideration.

So....you think a return from another unit outside the wall of your theater room on another zone will be quieter?:no:

If you are good with ductwork, then sizing returns and supplies can result in quiet!

 

[beenthere]

Putting a large return and a second register would bring the sound out of the room defeating the sound dampening enhancements I spent a lot for. It would work if ventilation was my only consideration.

Not if you use sound attenuated duct.