I'm thinking of knocking a hole in an external wall for venting the
exhaust of our portable air conditioner as I'm not keen on dangling the
vent out of a window. The unit came with what appears to be a simple
externally mounting flange with a seperate lid to cover it up when not
in use. I can see several problems with this though.

- The flange is wide open with no grille or slats or anything on the
outside. I can imagine all sorts of undesirable weather and wildlife
finding its way indoors.

- The flange being externally mounted and not very deep means that the
hose would have to be stuck through a rough hole in the internal wall
(concrete block, I assume), across the cavity, and through a hole in the
external (brick) wall. Would there be any problems with bridging the
cavity in this manner?

- The AC unit may be moved away from its present location over winter.
This would leave a gaping unfinished ugly hole in the wall, exposing the
cavity to the room, and leaving only the thin plastic lid on the outer
wall as a barrier to the cold outdoors.

Is there available a kit that provides a nice clean aesthetically
pleasing duct through a wall ,that can be closed at both ends to keep
the outdoors from getting indoors and that won't cause problems with
insulation?

Also, what tools would I need? This seems to be an excellent opportunity
to get my wife to agree to the purchase of a decent SDS drill

Matt.

On Sun, 14 Sep 2003 16:14:18 GMT, "Matt G"
wrote:

I'm thinking of knocking a hole in an external wall for venting the
exhaust of our portable air conditioner as I'm not keen on dangling the
vent out of a window. The unit came with what appears to be a simple
externally mounting flange with a seperate lid to cover it up when not
in use. I can see several problems with this though.

I did this job earlier this year.

- The flange is wide open with no grille or slats or anything on the
outside. I can imagine all sorts of undesirable weather and wildlife
finding its way indoors.

Once I had fitted the external flange (which had an integral plastic
door opened by the pressure of air coming from within) I bought a
small sheet of fine wire netting from the local garden centre. From
that I fashioned a small mesh grill which I araldited to the flange.

1/4in mesh, doesn't have any impact on the ability of the flange to
export air, but suitably small to prevent wildlife from coming in.

- The flange being externally mounted and not very deep means that the
hose would have to be stuck through a rough hole in the internal wall
(concrete block, I assume), across the cavity, and through a hole in the
external (brick) wall. Would there be any problems with bridging the
cavity in this manner?

To be honest I bought a 107mm plastic hole liner which was designed
for the job. Cost about a tenner if I remember correctly.

Also, what tools would I need? This seems to be an excellent opportunity
to get my wife to agree to the purchase of a decent SDS drill

I tried drilling the 107mm hole with a core drill and my trusty black
and decker 650w drill. Pretty soon volumes of smoke emerged from the
drill, a quick visit to the local DIY shed saw the purchase of a 900w
SDS drill, and it pushed thru the hole no problem at all.

In my opinion you won't be able to do this sort of job without a
suitable drill, and the average home drill won't cut the mustard.

PoP

"Matt G" wrote in message
...
I'm thinking of knocking a hole in an external wall for venting the
exhaust of our portable air conditioner as I'm not keen on dangling the
vent out of a window. The unit came with what appears to be a simple
externally mounting flange with a seperate lid to cover it up when not
in use. I can see several problems with this though.

- The flange is wide open with no grille or slats or anything on the
outside. I can imagine all sorts of undesirable weather and wildlife
finding its way indoors.

- The flange being externally mounted and not very deep means that the
hose would have to be stuck through a rough hole in the internal wall
(concrete block, I assume), across the cavity, and through a hole in the
external (brick) wall. Would there be any problems with bridging the
cavity in this manner?

- The AC unit may be moved away from its present location over winter.
This would leave a gaping unfinished ugly hole in the wall, exposing the
cavity to the room, and leaving only the thin plastic lid on the outer
wall as a barrier to the cold outdoors.

Is there available a kit that provides a nice clean aesthetically
pleasing duct through a wall ,that can be closed at both ends to keep
the outdoors from getting indoors and that won't cause problems with
insulation?

Try looking at the ventilation accessories sold for Vent-Axia or Expelaire
fans. They feature all sorts of louvres, anti-back draught flaps, cavity
bridging kits etc., in a range of different sizes. If your hose is 100mm,
you can find similar bits in most DIY sheds too.

Also, what tools would I need? This seems to be an excellent opportunity
to get my wife to agree to the purchase of a decent SDS drill

I would go for hiring a diamond core drill and the drilling machine to go
with it. It makes a much better job of holes of 100mm and above.

Colin Bignell