Originally Posted by ragged
Just read through, and I really like your design. I had the same plan as you for cooling the HT, down to the Panasonic fans installed in a utility room. I was really concerned about not having enough of a delta between supply and return air temp to make a difference and don't have the budget to install a mini split. My solution is to add a portable ac unit in the utility room, like the ones found at a local HD. http://www6.homedepot.com/acselector/index.html?storeId=10051&langId=-1&catalogId=10053
$400 and cold air supplied! I didn't find one that had the flexible duct, just blows air out through louvers, so I modified a rectangle to 8" register boothttp://www.homedepot.com/h_d1/N-5yc1v/R-202542040/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=register+boot&storeId=10051#.UOuOCXf0-ZQ
and duct taped it over the louvers. With the portable AC supplying and the fan drawing return hot air out, all should be well even if I'm dumping the return air back into the utility room. I may change that though now that I think about it. I'll plug it into an outlet controlled by a switch in the HT. I really need to find a wall mount thermostat that can turn on the outlet, but no luck yet.
This is an interesting idea. Actively cooling the supply's air has a lot of merit.
From reading my thread, you know I struggled some with cooling system - mostly due to static pressure in the supply line and too much noise from the velocity of the airflow. As for cooling itself, it so far seems OK, not great, but good enough that I'm not actively searching for a fix... But if I had to fix it, my first thought was to try to increase the "delta", as you put it, by rerouting the exhaust to dump into a rather large and relatively cooler part of my basement. That way, it seems that, by the time the air comes back to theater's supply, it would've cooled off quite a bit.
An alternative idea I have is to use another fan to actively move air around the whole basement. If you recall the pics of my basement from the early posts, it can be roughly thought of as being shaped like the letter 'C', with the only thing preventing it being an 'O' is a mechanical/storage room (the stairs come down in the middle of the basement). The supply is currently on one end of the 'C' and the exhaust is near the middle of the 'C', in a hallway that leads the supply on one side and the large space on the other. I'm thinking that a new fan could close the loop, that is, make an 'O', by piping air from one side to the other, though the mechanical/storage room, perhaps cooling it off some in the process, which would be good for me since I have some computers in there...
Anyway,since it's outside the theater and the current solution seems OK enough, I'm holding off on playing with it for now. But if it comes around again, I'll give your idea some more thought - thanks!