Advice on air-conditioning a 20m2 home theatre room...

post #1 of 6

6/24/12 at 12:57pm

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So here's the deal. I've bought an old house and will convert one of the rooms to a dedicated listening room/theratre. Where I live it is not actually not that warm during summers (equal to Juneau Alaska) but we have extreemely high building standards when it comes to insulation and energy conservation. Basically, no heat leaks in to the building and no heat dissipates... As part of the renovation I'll install a super energy saving "geothermal well heat-pump". Apart from harvesting ample amounts of energy from the well during the cold months, I can also dissipate ample amounts of heat down the well during the warm months, i.e. I get air conditioning pretty much for free (the energy to make 8-10kW cooling power is equal to the energy drawn by a couple light bulbs

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Thing is that no one up here seems to know how to dimension ducts etc. for a home-theatre when it comes to noise. My calculations indicate I need between 1 and 3 kW cooling in the room to be able to keep a nice 20-21 centigrades in there during summer months with equipment running and a coupe friends in the room.

Since I know there's a lot of knowledge about these things here I thought I'd ask for input -what sound levels and flow to aim for (size of diffusers etc) for decent sonic performance as well as other things to think about sound wise. I beleave the most scilent solution is to place a cooling unit away from the room(s) in the attic and the use "oversize" ducts and diffusers to keep the flow through them low.

thoughts?

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post #2 of 6

6/24/12 at 1:27pm

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Location: Pebble Beach, CA
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The rule of thumb everyone uses here is to design the duct for velocity not to exceed 250 feet per minute at the registers. So the general process would be to figure out the volume (cubic feet per minute) that you need to heat/cool the room, and then size the ducts to be ab le to move that volume at 250 feet per minute.

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post #3 of 6

6/24/12 at 2:00pm

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Quote:

Originally Posted by LeBon

The rule of thumb everyone uses here is to design the duct for velocity not to exceed 250 feet per minute at the registers. So the general process would be to figure out the volume (cubic feet per minute) that you need to heat/cool the room, and then size the ducts to be ab le to move that volume at 250 feet per minute.

My coolant will be between 5 and 7 deg. C which will give me around 10-12 deg. air temp from the unit according to the manufacturer.

OK....so according to my coolant temperature (7 deg. C) I'm looking at about 300l/s, which computes to 18 m3/minute… If I want it at a speed about 80 m/minute (=250 ft/minute), that's computes to a Square area of 18/80=,225m2.

All in all, I'd need a duct (or atleast outlet and return) of about 0,150m (6")?!??! Dosn't sound much at all...but I might have done my calcs all (or partially) wrong?

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post #4 of 6

6/24/12 at 2:24pm