CDA Island Extractor Not Sucking!

[sergeantash]

I can't fault your logic but there's certainly an air flap issue here somewhere!
Do post back with any findings.
John

Just spoke with one of their engineers - they commented the following:

- Ensure that the flexible ducting section is pulled tight, there should be no slack because the sides of the flexible ducting can cause vortexes and lack of suction.

- Smoke isn't the correct way to test, should only use steam because smoke is far denser.

- There is no switch on CDA extractors to convert between internal/external circulation.

I'm going to take it apart tonight and inspect it, hopefully be back to you shortly with good news!

He did say that if I need an engineer visit that they can arrange one but I'm being precautions not to incur the £45 fee if they find no unit fault.

Frankly however, a unit of this power I would expect simply to work and not to be this fussy about ducting configuration, particularly as its a straight up to ceiling and 2m straight duct to the outside!

 

[sergeantash]

I just took the lower extractor canopy off and inspected the ducting - what I noticed is that where I had raised the extractor up into its ceiling mount, the flexible tubing had distorted quite a bit, possibly enough to break the proper flow of air.

I retested with a steaming pan of hot water, the steam is running up into the underside of the extractor a little better now, but its not quite the powerful extractor that I thought it to be. Although steam is rising up into the underside, some is still escaping to the sides of the extractor.

I've mounted it 87cm above the ceramic hob, is it perhaps a tad too high? (I didn't want it in eye-line sight, also I don't want to be head-butting it) - perhaps I'm expecting too much?

 

[Lectrician]

I would NEVER use flexi duct for a cooker hood, always go for rigid and manufactured bends.

Similarly with bathroom fans, if you fit a larger mixed flow type, don't drag it's efficiency down by fitting a length of flexi - There is no point spending on a decent fan if you duct it poorly!

Most cooker hoods are fine with 5" 125mm duct, but if they spec 6", 150mm, perhaps you should go with it.

 

[sergeantash]

I would NEVER use flexi duct for a cooker hood, always go for rigid and manufactured bends.

Similarly with bathroom fans, if you fit a larger mixed flow type, don't drag it's efficiency down by fitting a length of flexi - There is no point spending on a decent fan if you duct it poorly!

Most cooker hoods are fine with 5" 125mm duct, but if they spec 6", 150mm, perhaps you should go with it.

The flexible pipe is only for the upwards stretch where it joins to a solid downward facing opening, connected to a 90 degree angle piece, which links to the solid stretch to the external vent. Now that its pulled tight, there is barely any ridge in that stretch.