I have some audio-visual gear (principally a video projector) mounted on a 
high shelf, just below ceiling level, in which position it's in danger of 
overheating unless I can increase the ventilation.  Directly above the 
ceiling is an unused part of the loft: if I install a vent grill (or even 
more than one) in the ceiling, will that provide enough of an escape route 
for the heat?  In this section of the loft the floor is insulated but not 
the underside of the roof, and the loft gets very hot in warm weather - will 
this prevent the hot air from the electronics rising away from the shelf? 
Obviously, I would remove the insulation from above the grill or grills.

I suppose the ideal arrangement would be a fan-assisted duct route leading 
through the roof to the outside, but I'd prefer something simpler if 
possible.  I assume that anything would be better than the present 
arrangement, which is a real hot-air trap.

It's one of those niggly things which I should have thought of at the design 
stage, but didn't.

Thanks in advance for any thoughts.

Bert
www.bertcoules.co.uk

Bert Coules  wrote:

> I have some audio-visual gear (principally a video projector) mounted on a 
> high shelf, just below ceiling level, in which position it's in danger of 
> overheating unless I can increase the ventilation.  Directly above the 
> ceiling is an unused part of the loft: if I install a vent grill (or even 
> more than one) in the ceiling, will that provide enough of an escape route 
> for the heat?  In this section of the loft the floor is insulated but not 
> the underside of the roof, and the loft gets very hot in warm weather - will 
> this prevent the hot air from the electronics rising away from the shelf? 
> Obviously, I would remove the insulation from above the grill or grills.


This will cause condensation in winter - unless the vents in the attic
are absolutely ideal.
What's wrong with a fan behind it, simply blowing the warm air into
the room?
Obviously, if the air above the hole is hotter than the air from the
projector, it won't rise.

Ian,

Thanks for the reply.


> What's wrong with a fan behind it, simply blowing the warm air into
> the room?


Nothing, except that I'd rather not have the extra noise.  Actually, I'm 
wondering now if it's the air *intake* to the projector which is the major 
problem.  It's situated at the rear of the unit, which places it very close 
to the wall: I suspect it's taking in air that's far warmer than is ideal. 
Perhaps I should be thinking in terms of directing cold air towards the 
projector rather than hot air away from it - though I suppose ideally, I 
should do both.

Bert
www.bertcoules.co.uk