Originally Posted by AirBenji
My issue isn't cooling the rack etc. - the equipment room is small (about 4.5' x 9.5') and I would like to bring the ambient temp down a bit in that entire space. I am also thinking about building a projector hushbox that will exhaust air into the equipment room, so that will exacerbate the heat issue I currently have. There is a supply and a return in the equipment room - I hope that simply adding the Panasonic fans mentioned above and a thermostat will be an adequate solution to increase the airflow and reduce heat buildup a bit. The current situation isn't terrible, but when you step into the equipment room there is a very noticeable temperature change. So...do you think the Panasonic fans (or similar) will work here? Thanks!
Yes, the Panasonic fans will definitely work. Given the size of your equipment room (I didn't realize it was that big), I would probably bump it up to an 80CFM model such as the Panasonic FV-08VK3
This fan will hook up to either a 4" or a 6" duct line directly, fyi. Panasonic also makes the exact same unit with a variable speed control to the fan, but probably not worth the extra expense.
Now, I hate to be the bearer of bad news, but the existing HVAC is a problem, unless it is a system 100% dedicated to the home theater zone. The problem is that given your northern climate, you are using the heating more than you would be using the cooling. As a consequence, your supply air will actually be supplying heat into your home theater equipment closet during your heating months. Having the return air there is no problem, provided there is enough supply to the whole room to equate to the air your are returning. So you have three options: 1. Remove the supply completely from your main supply trunk line and REUSE that line for the Panasonic fan to exhaust by discharge the heat; 2. Install very good dampers (ideally in two spots) where you can block the airflow coming through that supply during your heating months and then just separately install and duct the Panasonic fan, or 3. Re-route the supply into the main area of the theater and duct the Panasonic fan separately out of the equipment closet. Without researching it, I am not fully aware of what your total CFM input and output for the theater and equipment room is. But there is also one other complicating matter....like most well-built theaters with meticulous attention to detail to soundproof the room, the room is considered extremely tight. So it is absolutely critical
that you get the total supply and total return as balanced (equal) as possible. Otherwise if you are returning more air through the HVAC than you are supplying AND you now have an 80 CFM Panasonic fan drafting air from the theater into the equipment room and then vented out, you could wind up with what's called a negative pressure situation (deficit of supply). This negative pressure will make your sealed door very difficult to close as you will be fighting the pressure of the incoming air to be in pressure balance. If I were you, I would probably hire a professional to come in with his CFM anemometer and make the definitive recommendation and/or adjustments to your primary HVAC supply and return, given that the 80CFM of air removal from the theater by the Panasonic fan is a fixed measurement. It might be $200, but money well-spent to get things dialed in right. An intermediary step would be if you have a local tool rental place that can rent you the cfm anemometer (typically a $200 tool) and take the measurements yourself during maximum heating and cooling cycles. You may then find a willing HVAC shop to help you through any changes that need to be made via phone with the experience and calculation tools they have at their disposal.
Regarding the hush box - I would probably skip it. Seems like a lot of hassle for only a little db reduction payoff. Now if the primary reason to do it is that you feel your room is getting warm over the course of a full day of movie-watching, especially with all the chairs filled, then exhausting that heat directly into the equipment room for removal probably is a good idea if there is no way to keep the room 100% comfortable through proper balancing of the supply and return lines in the theater. Some food for thought.Edited by TMcG - 6/7/12 at 9:22am