What extraction rate do I need

[verybadhairdoo]

v.v.v confused with regards to kitchen extractors. Have found several websites that state min extraction rate for the room must be H WD of the kitchen. So, extractor hoods generally have 3 - 4 speeds. Which means what exactly? Does this min rate mean the lowest setting must extract that amount of air? Or say the rate required is speed 3. Would this be ok? Don't want to spend an exorbitant amount of money one one which ends up not doing the job!! Advice needed desperately!

It would help if you can tell us why you need to know?
Is it is going to be checked by building control?
Does your kitchen have gas cooking appliances?
Does it have openable windows with trickle ventilation settings?

You need to comply with part F (Eng & wales) building regs. general info is here:
www.planningportal.gov.uk/permission/commonprojects/kitchensbathrooms/
But there also min vent. requirements for safety if you have gas cooing appliances.

30 l/s over the cooker or 60 l/s elsewhere in the room if done as part of building regs app.

don't need it for building regs, just want to make sure that it actually works. In our current house I rarely use the extractor because it is so so loud, and in reality just doesn't work anyway. We have bought a new house and are renovating - its in such bad shape the whole thing needs to be gutted. So we need new everything. So don't want to spend £££ on an extractor to find that its excessively noisy or does not do the job. Have read some websites which state the minimum extraction rate for room sizes, but given there is usually a few speeds, what is minimum referring to exactly. No idea what trickle ventilation is [embarrassed]. You may have to enlighten me!

Trickle vents are little slidey things in the tops of windows, for background ventilation.

We have a new Rangemaster hood and it's very quiet & ultra efficient for both smells and steam.

Make sure it extracts to the outside air - don't get a recirculating extractor - they're rubbish.