Ductless AC and fresh air

Hello My name is brad. I'm a new here. wasn't sure if this question is in the correct section. Building a room in a New Jersey condo. Room within room, 2 layers 5/8 sheetrock. ISOMAX clips. 12'x16'. This apt has a small 8" duct feeding the room which I am building the studio in. it is part of a central air unit for the condo with no zone controls. Original plan was to duct a return out of studio and use this . I doubt this will do the job, so I am going to a ductless ac or heat pump. Compressor outside, cooling unit in the control room. ( single room studio for mixing and midi tracking ) My concern is if this room is " Air tight " could carbon dioxide build up in the room. Should I leave the old duct to just add a little fresh air? If I just want a little fresh air, do I need a ducted return from this room.? Thanks in advance for you input. Brad

if you build the supply/return to the room large enough, you could be able to completely and effectively exchange air with the condo. that said, it would likely require some decent fans, silencers etc to make it happen. even if you do use a smaller inside-the-room AC, you'll need air exchange...

I had a similar situation and I ended up using on of the Fantech fresh air/heat recovery units (along with a Mitsubishi Mr. Slim ductless AC unit) Check out : http://www.fantech.net/hrv_erv.htm

gullfo wrote:

if you build the supply/return to the room large enough, you could be able to completely and effectively exchange air with the condo. that said, it would likely require some decent fans, silencers etc to make it happen. even if you do use a smaller inside-the-room AC, you'll need air exchange...

If there are no windows or doors from his room directly to the outside - what he's thinking (and you're proposing) is a violation of both the building and mechanical codes. The code requires each habitable room have a direct connect to the outside world in the form of either windows - doors - or through mechanical means. The code then goes on to describe how one might take air from an adjacent space into another space. One of the requirements for this to be the means is that there can be NO doors between the 2 rooms - there must be a clear opening - of the size proscribed by the code - that can never be closed off - and THAT other room or space has to then have the direct access to the outside world. For mechanical means to satisfy the code - the ducting itself must be directly connected to outside air - and the existing HVAC system (even if it had fresh air supply - which is VERY doubtfull) does not meet the requirements under the code. The poster needs to begin thinking along the lines of how he can go about getting outside air ducted into his room. Sincerely, Rod

thanks Rod - i was thinking more along the lines of a booth within the room, not specifically a room... I definitely agree if he's going with a room approach it has to be built to code.