I am building a new home with an audio closet for my stereo equipment (950/770 combo). I am concerned about how to vent out the heat generated from the 770. Does anyone have a simular set-up and how did you take care of the heat ventilation?

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dfs

I am still in the process of sorting through this myself, but I am always a bit surprised when I open my cabinet that houses only the 950 and 770. Each on a sep. shelf in a space 36 wide by 40 high and 34 deep. Theres a lot of boxed in heat. I am going to try and open up a vent in the shelf above that is open to roon air and see hoe convection works. A number of people have recommended some sort of fan also to keep circulation. If you are housing all your eqip in one closet you might at least consider putting the 770 at the top.

I haven't tried to do this (my stuff's in an old entertainment center), but the 770 will definitely need some air movement -- without some sort of vent, you effectively have a space heater in an enclosed space, and the temperature will rise steadily until it is a danger to the equipment. The 950 puts of comparably little heat, but still needs a little ventilation. In a totally enclosed closet with a lot of gear in it, I'd look at perhaps an undercut or louvered door and maybe a ventilation fan (something that could discharge hot air into an attic, for example).

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

ive known people to put a computer power supply in their racks and connect some (computer) fans to it. i dont know if you are into computers, but i know i have some extra power supplies and fans. plus you can get the stuff cheap and its an easy and quick fix even if you dont have any spare stuff.

For that matter, little bathroom vent fans can be had at Home Depot for under $30 -- and they'll move more air through a closet than a PC case fan, without the heat gain from a PC's power supply (which has a 120V to 5V transformer in there, all nice and toasty, while that little vent fan has a fractional horsepower motor that produces much less heat).

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

OK, I got to thinking about this some more this morning and dug out some notes from a recent project. Real-world heat gain data from electronics like amps is extremely difficult to pin down -- in addition to being somewhat dependent on the actual load being driven (at least for solid state amps; tubes should be a lot easier to figure out since they are more like incandescent lights), there is no guideline or standard for measuring heat gain of electronic equipment. It's all a little fuzzy, but I recently took a stab at guessing some realistic heat gain values while doing loads on a facility that included viewing rooms equipped with 5.1 surround systems. Keep in mind that all of this mumbo-jumbo is assuming that the equipment is located in a small closet with no ventilation (closed door, no air vent, ...) -- sort of a worst case scenario.

Assuming a fairly typical system -- five channel amp, 150W or so per channel, pre/pro, DVD, satellite or cable box, maybe a VCR -- the peak electrical consumption will be over 2000W. Not all of that is heat gain, and that consumption is the peak anyway. I ended up estimating (guessing -- gotta go with the SWAG sometimes) that a system like this might generate 1000W of heat. It could be even higher, but for the sake of argument even this ends up being a significant load. So we've got 1000W, which equates to 3412 BTU/hr (or about 0.3 tons of cooling load). If we plan to cool this by ventilating it -- drawing room air through and dumping the hot air somewhere else -- we want to establish some limits on the temperatures we'll allow. The entering air will be 75F (could be lower depending on where you have your thermostat set, but 75F is a safe value in a house), and I'd like to keep the discharge air below 90F if possible. With 3400BTUH and a 15F temperature change, the air flow required is approximately 210 CFM (cubic feet per minute; CFM = BTUH/(1.08*delta-T)) -- in a small, totally closed closet, that's a lot of air, over 1.5 air changes per minute in a 4x4x9 closet. A 1" undercut on the door will allow about 100CFM into the room, so a louvered door or door grille would be needed to get that much air in. The air could be discharged into an attic or to the out of doors, but you want to keep the discharge ductwork short to minimize the work required by the fan.

Bathroom exhaust fans range from 50CFM to 110CFM ( this fan , for example, will move 110 CFM and sells for around $50), and can be easily configured to discharge straight into the attic or to a louver or roof cap. Other exhaust fans (such as this one ) can be had that will go up to 210CFM pretty easily. PC case fans can move 35CFM (for an 80mm fan) to 75CFM (for a 120mm fan), but with no more than 0.10" of static pressure. An exhaust grille alone could generate 0.05" to 0.10" of static pressure drop, making it very difficult to get all this hot air moved anyplace very remote. "Wall wart" AC adapters could be rigged to power these fans; many people use such adapters connected to the accessory outlets of receivers to power small fans. A PC power supply could also do it, but the larger AC/DC transformers will add a lot of heat -- typical PC's produce around 100W of heat, due primarily to the CPU and power supply (with some also due to the hard drive and such). Adding 50W of heat from the power supply equates to over 150BTUH, or a 15%+ increase in load.

On paper, there's not much if any factor of safety in these numbers (the numbers could even be considered low, if the nameplate data is to be believed). In reality, I would guess that a safety factor of 1.5 or more exists in these calculations. If you had 100CFM+ of air movement (an undercut or louvered door and a decent exhaust fan) in a small, otherwise sealed equipment closet, you would probably be OK, and a week or so with a cheap digital thermometer in the closet to track temperatures would let you know for sure. In a freestanding equipment rack, simple openings in the rack or a 120mm PC fan powered by an AC adapter ought to be able to keep things under control. In any scenario, I'm assuming that you have the recommended clearance around equipment (especially the amps) so that they can get air in and out readily.

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

Thank you all for your suggestions, especially GONK. You've all given me a lot to think about. The closet is about 4x4x9 with a pocket door in the theater room and a rear solid door (for access to wiring) in a spare bedroom. I should be able to give an inch for hte rear door and add bathroom vent into the attic (above the equipment closet). Now I just need to locate one that is as quiet as possible...

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dfs

Look into these Panasonic models. They are VERY quiet.
www.panasonic.com/consumer_electronics/bp_ventilation_fans/default.asp

That sounds like a plan, then. Let us know how it turns out, dfsmks.

And those are some very quiet little fans -- the FV-11VQ2 is rated at 1.5 sones, which may be the lowest I've ever seen on a fan.

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

gonk, you have a lot of freetime or a very boring job! j/k. interesting data you calculated above. i dont know too many people who have that kind of airflow in their racks... a lot of exhaust fans are pretty noisy, well too noisy to be acceptable in a ht. i would recommend a configuration of an array of fans that suck air from the bottom and pull it up through the system and eject it at the top. cooling is achieved by pulling air across a surface much more quickly than allowing the heat to naturally radiate and then eventually being pulled out. hence the design of computer heatsinks. id think his whole house would be hot with 75 as the room temp.