Cooker hoods - Educate me please?

[Andy Luckman (AJL Electronics)]

Well after nearly two years, the kitchen is approaching completion. Had Mr Corgi over to connect the gas hob and 'er indoors decided to try it out by boiling stuff for about 100 years on all four rings. You can imagine the condensation!

I wasn't going to bother with a hood, but now I see that it might be sensible to actually install one.

My problem is that the hob is not near an outside wall. I have looked at hoods generally and see that most of them are vented through the wall. A few are "island" hoods that vent vertically.

How do these things actually get vented to outside? A long flexible like a tumble dryer pipe?

I need something that vents straight up then moves 90 degrees to follow the ceiling joists, before exiting. A distance of two or three metres.

So I obviously know little and hoping for some education. I'm not keen on a recirculating because I don't feel that they will deal with moist air adequately enough.

[Stuart]

This of any help ?

[Chris Bacon]

Use Osma soil pipe (above ground).

[Andy Hall]

You *can* do that, but it's not very good because of the ridges in the pipe. It is best to use ridgid round or flat ducting with as gentle bends as possible. You end up with a trade off between appearance and fitting into the space vs functionality - i.e. if you run a

120x50mm duct for more than a metre or two and have sharp bends in it, then you can expect the performance to be pretty poor.

If you can run the duct upwards, through the ceiling and run through the space above, you can achieve a lot. In that case, for this length, go for a 125mm round duct rather than a 100mm one like soil pipe. If you are going 3m it will make a big difference even if you use a 100mm duct hood. First it will run better and second it will be quieter.

These are completely useless. They won't do anything for moisture and not much more for grease.

Go for a hood that vents and has removable metal filters. These can be taken out and put in the dishwasher so cleaning is easy and there are no consumables.

Have a look at

are an Italian manufacturer who produce virtually all cooker hoods sold in Europe, be it their own or private label for other manufacturers.

[Michael Chare]

Yes, and or with plastic box tubing. There is a kit that you can buy for the Bosch/ Neff ones. You may well be able to buy suitable parts in one of the sheds.

That is what mine does (well more like 1.5m horizontal.) The vertical part is round flexible hose. The horizontal part is rectangular cross section and is above the cupboards.

It does work very well. No condensation on kitchen windows.

[Mathew Newton]

As others have said, a flexible (ridged) hose impedes airflow, and significantly so over long distances. If your ceiling void allows it then smooth/rigid ducting will be far superior.

In my case, being in similar circumstances to yourself, I bought a Baumatic canopy hood from TLC

which, at =A3100 for a 500m3/h freeflow is hard to beat. It has a 5" outlet and so I bought a coupler (from BES?) to marry this to 6" ducting. The ducting consisted of a 1.5m rise to the ceiling (void), a 90deg bend and a 3m horizontal run to the outside wall. The exterior was finished with a gravity flap as there is none such fitted to the extractor itself (and thus would be draughty when not in use).

The setup works superbly (I calculated the figures for the back pressure of such a ducting run and this, coupled with the fan flow graph from Baumatic, confirms the good performance). It also looks the nuts too... IMHO! Incidentally, I didn't think we'd need the downlighters however since having them I (or should that be 'she'?!) couldn't live without them - a real bonus whilst cooking on the hob.

You can see the ducting run at the following URL: (the frame is a lowered suspended ceiling, mid-construction)

extractor mid-build:

the final product at:

[Andy Luckman (AJL Electronics)]

[Andy Luckman (AJL Electronics)]

OK I have more of an idea now, I have been looking at a Beaumatic QF9? Moves air at up to 500 thingys. :-)

My difficulty is in getting the vent outside without too many sharp angles and visibility.

I just might post some pic next week for you to have a laugh at!. I will also have to move the hope 6 inches to the left to make it look balanced if I fit a hood.

[Andy Luckman (AJL Electronics)]

With the way the joists run, it looks like I will need a couple of sharp 90 degree bends unless I can think of another route.

Interesting. The Beaumatic chimney hood is the one that caught my eye. Sadly the white one is greatly more expensive than the stainless.