[DMT]

My builder tells me that my garage conversion will be airtight after he has sound proofed it; this obviously throws up concerns of cooling and even breathing! He says that I cannot put in air con as this will compromise the build, as there is to be a room within a room and therefore no holes in the wall.
Any solutions please.

[hornydragon]

erm has it got a floor? a door? aircon works on 2 units one in room and heat exchanger out side with power and some small lagged pipes between see here for more info http://www.daikin.co.uk/aircondition...pe/default.jsp make sure the system has rs232 or ir control for integration with hc remote

[davee]

You've got the right idea even if your builder hasnt. You need to have air changes in the room for your own comfort and also to control the heat build up. All that equipment giving off heat before you factor in the human condition can get very uncomfortable. - especially with a pj running.
There are ways of sound proofing without comprimising on ventilation and vice versa. A domestic air con unit will only chill the ambient air, you need to have a constant turnover of fresh air or you'll be asleep before the film finishes. This can be done using sound attenuating transfer boxes but you would normally build these in with the construction.
The requirements for the provision of ventilation in dwellings are detailed in the Building Control Regulations and apart from providing fresh air to breathe, are meant to restrict the build up of moisture and pollutants, which would otherwise be a hazard to health.
Ventilation rates are usually quoted as 'air changes per hour' defined as the volume of ventilation air moving through the room per hour, divided by the volume of the room itself.
BS 5449 stipulates 1.5 air changes per hour for a living room.
Have you asked your builder how he intends to achieve this?

[DMT]

Thanks for the great reply. My builder seems to have a 'lets suck it and see' attitude. He had no prior knowledge of sound proofing and has been researching heavily in this area but is concerned that any channeling from inside to outside will then spoil all of the good work.
I think the plan now, is to build a trap door in the ceiling and see what effects that has on sound polution when opened slightly. Pehaps a retro fit unit could then be added.
I wonder whether he and I are taking this all too far, trouble is I just don't know how loud things are going to get until it is done!
It is a detached garage by the way.

[davee]

Just read your kit list, How big is the room going to be? you wont want any additional heating will you
Cant work out what youre trying to do with a trap door in the ceiling

[DMT]

Double garage approx 17' x 15'. The trap door is too allow access to loft space if required in the future. I think he is saying that if we open the trap door a little then this will give us an idea of how much sound would escape were aircon to be installed.
I have seen his work and it is very good (plus cheap, always handy ) perhaps he is just alittle out of his depth/ comfort zone, as of course am I.

P.S. As you say, from my kit list, things could get very loud and very hot even before half a dozen bodies!

[hornydragon]

erm stupid question but why is the loft sonically isolated from the cinema? incase you wake the cardboard boxes? ideally you ceiling should be silk and stuffed full of accoustic bass traps with the inside of the tiles soundproofed. It is also possible to fit aircon them build a sound proof box around the ceiling unit dont forget that aircon even expensive aircon isnt silent

[DMT]

This is a detached garage with a pitched roof so there is no loft space as such, there is also no insulation and so we have to sound proof the ceiling some way; i guess the easiest route is to square off the room and board the false ceiling.
I actually love the idea of using the whole space and added height but i think the beams would resonate and act like a giant speaker.

[davee]

If you have soundproofed the space but have a void above then that’s good news for the a/c anyway. Ideally you should install a ‘split system’ which is where you have the condenser sited externally and the fan unit internally. The fan unit need only be a chassis unit, ie, no casing around it, and this is sited in the void above the ceiling. Insulated flexible ducting then supplies chilled air into the room through a grille or grilles in the ceiling. The advantage of this is that the mechanics of the fan unit is remote to the room and the only noise will be the airflow into the room, which you wont hear above the noise of the pj let alone whatever is playing. If you get an inverter unit for a minimal amount extra you can have heating as well, should that ever be necessary.
Look at Daikin for a quality machine http://www.ventyourhome.com/pages/HRVsystem.html

If you havent put the ceiling in yet, taking the void above into the room will be beneficial acoustically because it will help eliminate standing waves, the beams wont resonate. However I suspect if it was built as a garage the construction wont be sufficiently attractive to have it on display.