HVAC - exchange chamber questions

OK - getting close to finalizing details so I can get started.. HVAC is the last stumbling block (for now). Here is my plan - I fully expect you fine folks to find major faults with it.. but that's why I'm here. So.. important facts first: Adjacent to my planned studio build (2 rooms, control room & drum/amp room) is a 'mechanical' area. My whole-house breaker boxes are there, network patch panels, video patch panels, etc.. and also 2 of the 3 air handlers for my house. The two air handlers are for the floor where the studio will be built, and a 2-zone for the main floor of the house. The system uses forced-air gas heat.. so the same air handlers/ducts are used for both. The area where the studio will be built was designed by the builder as a home theater, and is currently fed by the downstairs air handler with HVAC - this room was designed to be serviced by the whole-house HVAC including a lot of equipment and a half-dozen people watching movies. I opted to go for studio instead of theater. The plan.. I would like to move the existing duct/register that feeds the studio area over into the mechanical area, and possibly run second duct/register from the 2nd floor air handler into this area as well.. This would keep the mechanical area well cooled/warmed as needed - and would function as my exchange chamber. I should be able to run a fairly large duct from there into each room - probably 10 or 12". I can then run the return back into the mechanical area, or vent it out elsewhere. The plan is to have the fan on the supply side, creating positive pressure in the rooms. So, as I see it - normally, using part of the whole-house HVAC is a no-no.. but in this case, it was designed to cool this area including a lot of bodies and equipment.. I also have the benefit of two air handlers worth of supply air, cooling, heating. So - there's my plan.. I think it's fairly well thought-out (probably wrong).. poke holes in it, please!! PS: any issues with not having a grill on the supply registers? was thinking of just leaving the gaping hole, and hiding it with the ceiling 'cloud' above the listening position. Thanks in advance!

Thoughts?

Perhaps not enough information.. so here goes... Room sizes: control room - approx 300sf, drum doom approx 100sf (rounding up, since the rooms aren't perfectly rectangular) As far as heat-generating items within the rooms: Lighting - my current plan is to use mostly LED lighting. Off-the-shelf track lighting, replacing the GU10 bulbs with LED equivalent - long life, low wattage, and virtually zero heat. Drum room will house drums and sometimes a couple of tube amps (100w, 50w, 15w respectively) - likely will never have more than one person at a time playing in there.. two at most. Control room will house probably no more than 2-3 people at a time (this studio is for me and friends, no more recording other bands!). Total wattage of my console, monitor amp and outboard gear is well under 1000w (approx 600) plus a computer (450w power supply and 2x LCD monitors). So safe estimate is about 1000w for equipment, and about 90% of the time a single sedentary person. Using Rod's HVAC calculator - this setup will require approx 6600btu/hr for the control room and appros 3700btu/hr for the tracking room, but this is also figuring an extra 600w/200w for lighting for the 2 rooms - and I will be using nowhere near that number. Thanks

I wish I could help you there, but I know as much about it as you do, having read the same book and the same forum! :) To me, it seems like your plan follows Rod's recommendations, so I don't see why it wouldn't work! The only comment I'd add is that maybe a min-split system might be another alternative to do the job of cooling that room just fine, but it doesn't solve your ventilation issue. Not sure if that helps any! (Probably not...) - Stuart -

Thanks, Stuart.. I'm hoping Rod will chime in on this one himself. I THINK that my plan is pretty solid, but just want to make sure before I commit to it. The pain and expense of being wrong would be huge. "-)