Stoves Sterling 1000 cooker hood ducting size

[tireetim]

Can anybody help me with this - need to resolve asap as it's holding up my kitchen install and I can't get through to Stoves for an answer.
Can this hood use 125mm ducting without degrading the performance? The manual only mentions 150mm but it is supplied with a 150-125mm reducer so I assume it's ok to use 125mm from a warranty perspective. It goes up to about 650 m3/hour (although this figure is different on the manufacturers web site, dealers web sites and spec sheet supplied so the real figure is anyone's guess).

Thanks.

 

[Doggit]

Having had a quick look at the stoves website, it seems to indicate both 150 and 120 duct sizes; and if it supplies an adapter, then that alone implies you can use either size, even though the website doesn't state that an adapter is supplied with the kit. Obviously, if it's trying to shift 750 m3/H, then the smaller ducting size would restrict the top speed, and make the motor struggle, increase the noise level, and burn the motor out quicker. If you don't use the top speed, then you should be fine with 125mm. Having said all that, would you want to remove 750 m3/h from your house. It'll certainly take out all the smells from the kitchen, and the heat from the house at the same time.

 

[tireetim]

Thanks Doggit. It's just I've got all the bits for 125mm and would have to buy 150mm and cut bigger holes etc otherwise I would have just gone 150. Think I will try it with the smaller size. Very disappointed with Stoves customer service. No replies to emails and eventually got through on phone to speak to somebody (after trying all day) who didn't even know what a duct was. Eventually she broke all the rules and put me through to a technical chap who was better but still didn't know what size I should / could use.

 

[Doggit]

There are websites that will give you calculations for ducting sizes, but the ones I found suggested that 125 would only handle 80 ft3/m which translates to 140 m3/h. I'm amazed that Stoves couldn't give you any help, and I'd be tempted to put a complaint in to the MD. Should have asked how far the ducting is going, as that makes a difference.