ceiling vs downdraft kitchen extractor

mymedi

I was wondering if someone might have any insight into the problem I'm facing with our kitchen renovation.

For design reasons we really don't want a standard above-hob extractor. Which leaves us with either a downdraft or a ceiling one.
It's about the same price once you consider all the extras - the cost of granite cut out + coring a solid stone wall to vent to the outside for the downdraft or the cost of installing the ceiling extractor, making good the ceiling and making a roof flue for venting.

Granted that the downdraft is not that efficient at extraction, but...
Our kitchen ceiling is at 3.25m and the room size is 5.1x3.9m. So, my concern is that at that height the extraction of the ceiling extractor would not be much better than a downdraft...? Is this a valid concern?

So my dilemma is this - since we're spending this money anyway, which one would be more functional?
Any good brands/models you can recommend from experience?

Thank you.

ryder72

Ceiling recessed every time. All heat rises and a ceiling recessed unit will do a brilliant overall job.

Is your budget permits it, get one with an external motor.

Gutmann do fabulous products but they are very expensive. Westin made some excellent quality products too. I'd steer clear of everything else.

mymedi

Thank you, ryder72! Very useful.
Anything in particular that turns you off downdraft extractors? Are they really that bad at their job?

Rockingit

Building regs plays a part in this, too. If you're refurbing an existing kitchen then technically the below doesn't apply, but it is considered good practice and design to.

Part F (ventilation) says (table 5.2 if my memory is correct) that in a domestic kitchen you need 60l/s mechanical extraction to the outside, or only 30l/s if fitting an over hob extractor - the logic being that they are more efficient and directly over the source of likely pollutants. Hence why the vast majority of new builds have external venting cooker hoods as standard. 60l/s (compared to only 15l/s required in a bathroom [6l/s in a WC]) aren't the most discrete of things!!

ryder72

mymedi - Downdrafts are are great looking gadget. But the practicalities are against it. It takes up space behind the hob for the internals, ducting out can be very labour intensive and expensive, Most importantly - performance wise, heat rises and what a downdraft does is works against rapidly rising heat. Grease/odours that escape the extractor pass into the room. Grease settles and odours hang around.

Ceiling recessed hoods depends on creating a good draft to extract so its important that hoods are turned on a good 10 min before cooking but once you have a draft going, they are brilliant. Fitting is relatively easier too.