Venting heat from Electronic gear outside?

Calibos

I asked this question over on a Home-Cinema forum and never got a reply. I've just realised that I was asking the wrong people and that the experts on loft insulation, roofing, air tightness, energy ratings etc etc are the guys to ask.

So here goes. Our recently renovated home had its loft converted and its going to be a Home-Cinema. Running the 5m length of the room is an eaves storage space. Its a nice handy space about 1.5m wide and 1.5m tall at its highest point. I got the builders to inset a Home-Cinema equipment rack which projects into this space. There will be openings cut out at the back and Thermostatically controlled fans pulling air past the hot gear and venting it into the eaves storage space. There will be a projector mounted on the gable wall and I will be ducting the fans of the Projector to this eaves storage space too. Within the eaves storage space I will/have my Sat TV multiswitch loft box, gigabit network switch, patch panel and multi terabyte content server.

As you can imagine there will be a lot of heat generated by the electronics gear (ducted to/generated within) this eaves storage space and certainly in the Summer it will get very hot very quick.

The plan is to fit some more thermostatically controlled extraction fans within this eaves storage space venting to the outside. The question is, how I go about it. My first thought was after pushing my hand through the insulation over the side wall of the house as it were, I could feel the inside surface of the plastic fascia. I figured I could seal up the inside of this eaves storage area but duct the extraction fans out into this non air tight area behind the plastic facia.

Then a thought occurred to me. Would all this hot humid inside air I am venting behind the plastic fascia condense on it and/or and possibly pool or condense on roof timbers.

Should I instead remove a roof tile, cut through the roofing felt and fit a rooftile vent with extraction fans venting air out through those.

The first idea is definately DIY, but I might have to get an expert in to do the second idea.

(BTW. I think I will come up with some divertor vane for the Projector fan ducting. ie. In the Winter set the projector ducting to vent into the room instead of the eaves storage space and maybe fit a single 'Winter' fan on the equipment rack blowing the gear rack heat out into the room instead of the storage space. I don't think I will ever need to use the rad in that room )

Calibos

Calibos wrote: »

I asked this question over on a Home-Cinema forum and never got a reply. I've just realised that I was asking the wrong people and that the experts on loft insulation, roofing, air tightness, energy ratings etc etc are the guys to ask.

Or maybe not.....

gman2k

eh, your post was a bit long, so I've just skimmed through it (sorry)
Basically, if you are going to create a mechanically vented area, then it should be directly vented to the outside air, not to any void in the construction.
However, I think you are going for an overkill option, looking at your AV equipment, there's only one amp, so the heat generated won't be terminal for the area. It would be different if you had a number of high output amps in that cabinet area.
It's more important to have necessary clear air space around the equipment - as outlined in your equipment manuals.
Place your amp on top of the rack, as this will be the biggest heat generator.
If you are still intent on venting this cabinet, then just consider venting back into the room, as all you want to do is create an airflow over the electronics. Venting to the outside will not result in a lower cabinet temperature.
Finally however, consider that installing a vent in your cabinet will result in dust being sucked though this area, which may have a greater detrimental impact on your equipment.
A look at a computer hardware website will give you plenty of options for install fans etc that could be built in with a little DIY know how.

Calibos

Thanks for the reply Gman. Its a fine line between creating a post with enough info for respondees to be able to answer or a 'tldr' post. In hindsight I think I may have leaped over that line

Even though I have misdirected you with one of the pics I think I can take from your reply that even with a small amp and not much else, its not a good idea to vent out into the space under the eaves behind the fascia/soffit??

As for the pic in question, that was just to show how the equipment rack is recessed into the eaves storage space. The gear pictured in the rack space are just an old dvd player and scart switcher destined for the great Weee recycling centre in the sky and two NTL stb's due to be returned to NTL. I just shoved them in there out of the way the other day.

When the room is done there will be a big 7.1 av receiver, HTPC, SkyHD box, 360 and PS3 in there. All prolific heat generators as I am sure you know. Inside the Storage space there will be TV distribution loftbox, gigabit switch/patch panel, big 10tb+ server. I also want to vent the Projector to the storage space too.

I've had, while not quite that much gear but not far off, in a garage conversion home cinema in the past. With the volume necessitating the windows staying closed in Summer, I know how much of a furnace a room with all this equipment can quickly become.

Thats why I want to vent it outside

gman2k

Ok, but you should then vent directly to the outside, never to an enclosed part of the construction.
It's not just hot air from the cabinet you'll be venting, but moist air from the house in general, which if it comes into contact with a colder element of the construction will result in condensation and possible rot.

Calibos

gman2k wrote: »

Ok, but you should then vent directly to the outside, never to an enclosed part of the construction.
It's not just hot air from the cabinet you'll be venting, but moist air from the house in general, which if it comes into contact with a colder element of the construction will result in condensation and possible rot.

Cool. Thats exactly the kind of answer I needed. Thats what occured to me and gave me pause for thought about venting outside but behind the fascia/soffit which would be DIY for me.

The other option is to duct through the insulation to a new vent roof tile over the eaves storage area. Probably need to pay a roofer to do this for me as opposed to it being a DIY job though.

Its just great though that the location of the room and this eaves storage space is perfectly positioned within the house for this to be such an easy job albeit not a DIY one.

slavetothegrind

As you are doing it properly i would suggest a glass door to reduce noise but more importantly to reduce dust.

If you were to fit a lint screen at the bottom of the rack above a vent hole from the room into the rack.

this will trap the dust from the room and stop build up in your amp, blueray etc.
it can be removed and cleaned as needed.

A smoked door might look good!

Nice looking room by the way! am a bit jealous.;)