Thanks in advance for your replies and advice:
I am building a new house and I will have a dedicated HT room. It will be in the basement and underground, with 2 of the 4 walls the exterior (cement foundation). I live in Utah (go utes, byu sucks!), where it gets cold in the winters and hot in the summers. It will have a projector and will seat typically 2 or 4 people, but possibly more (seating max is probably 12 - front row will be bean bags for kids, the 2nd and 3rd row will have theater-style seating for about 4 people per row). Many people would (hopefully) be a rare occurrence - and I don't want to spent excess money for a rare occurrence. Also, sound isolation is somewhat important (I will likely go to the effort of double drywall with green glue and clips/hat channel for the ceiling).
The room is 22 feet long, 19 feet wide - with a varied ceiling height - 10 feet at the screen, 9 feet in the middle and 8 feet in the back. The total volume is roughly 3800 cubic feet. There is also a 'audio' room, roughly 6' x 6', in the back where all the audio equipment will be.
My first question is regarding heating and air-conditioning. I have read here on AVSForum that even in winter, a HT room could get warm enough to need cooling. Is actual air-conditioning necessary? Or just have the air circulate with other basement/house air? Can you have your air-conditioner going in winter? If so, do you basically have to have a separate furnace/AC for the HT room?
Currently my house is planned for 1 heater with 3 zones (one for each floor), with the HT room part of the basement floor. Is that sufficient with a reasonable amount of money spent?
Would a 4th zone be suitable - add a separate zone for the HT room? Is this possible - how could a HVAC system simultaneously heat one floor while trying to cool another?
Would a second HVAC system just for the HT room be the best, especially for sound isolation?
My second question is easier: I will have central vac for the house, but I was thinking that the extra 'coupling' of the vac system in the HT room would compromise the sound isolation and allow a pathway for sound to transmit throughout the house. Any thoughts? Experience? I was thinking of not doing central vac for the HT room for this reason - the inconvenience is minimal (having a vacuum for the room versus dragging a hose and vacuum) and the potential benefit of improved sound isolation is worth it.