WWYD - annoyed builder has put in a duct in kitchen that won't fit new extractor...without asking us what extractor we're having!

[gobblygook]

Apparently, my DH and archfriend have gone to our house to look at work, and the builder has put in, what looks like a 100mm diameter duct - when ALL the integrated cooker hoods we're looking at require at least a 123mm or 150mm duct.

I'm pissed off. Pissed off no one asked us even though I did offer to list all the appliances we're thinking of buying.

WWYD? I've emailed builder 'asking for his thoughts' and no doubt will hear back from him in the morning, but is it a big deal for him to now change the duct? Should I stand my ground? The kitchen to living room is quite open plan and good extraction is important.

Or can anyone recommend a decent 60mm extractor that might fit a 100mm duct?

Sorry this is such a boring post - but when you're in house renovations, EVERYTHING feels so important.

the standard size for an extractor duct is 100mm.

what is the extract rate for the hood you have in mind? How long is the duct?

it is possible to fit adaptors between different sizes. I recently got an Elica stainless 900mm which fits a 100mm duct. I couldn't find a 1000mm plain hood.

Assuming he is using a core drill, it is hard to enlarge a hole since the drill relies on the brickwork in the centre to hold the pilot steady.

If you had warned the builder you wanted a large duct it is his fault for cutting a standard size, but not otherwise.

Er thank you so much for replying Piglet John...but no idea how long the duct is. The extract rate I'd like is about 450...saw a Neff one I liked.

I've had a good look online at different decent extractors today and virtually none of them take 100mm duct. Given that his company has been employed to do a shit load of work, and it's not been cheap, it just surprises me that he might not think we want to put in a good extractor, with good extract rate...

I'll ask him about the adaptor.

I did ask him if he wanted to know all my appliances for reasons like this...

the length of the duct is the distance between the outside of the wall it goes through, and the spigot on the extractor. If it is an unusually long way, constriction will reduce airflow.

You're right, the 120mm ducts are not as unusal as I thought. Just looked at instructions for mine, it can be 100mm or 120mm (it has the duct running on top of the wall units out of sight). Builders usually have lots of 100mm duct (it is also used for bathroom extractors, and you can use UPVC soil pipe, which is ubiquitous).

Lots on here but it is not a flashy shop.
screwfix

450m3 per hour is quite powerful. I wonder if it will be noisy?

I like to have a hood that's wider that the hob to suck up any sideways drift.

this is the sort of adaptor I meant they call it a reducer

Hi PigletJohn

I'm not sure exactly, and I could be talking out of my arse, but I think the extractor will be about 3.5m from outside wall.

The one I'm thinking of isn't this one but it's also a Neff - this is the one recommended by Which? Nett extractor hood - it's got a good extract rate, and according to the catalogue it's really really not noisy (equivalent to a refrigerator). And it's quite cheap - £130

Sorry should say Neff extractor hood

that one is 600mm wide, and has a Maximum extraction rate:- Power level 3 360m³/h which is not as powerful as you were thinking of before.

Recommended duct length is usually 1 metre to 3 metres, so yours is a bit longer than usual. If it was me I would get a wider and more powerful one. I take it you want it to be concealed behind a false unit door.

As you have such a long duct I take it that your cooker is not on an external wall so you will have the duct concealed above or inside the wall units as it runs towards extenal wall with the hole in it.

Hi piglet John - thanks so much for such an informative post! Yes as I said the link wasn't to the extractor fan I had mentioned previously - but I couldn't find the link to that

No - cooker isn't on external wall

Will def look at duct lengths and come back later!