How to lay extractor ducting in solid subfloor

[Flygirl]

As part of our kitchen extension, we are planning a downdraft extractor in an island, as we’re taking up the current floor anyway, we’re trying to figure out the best way to vent it externally, ie. where within the concrete subfloor construction should we lay it? Our subfloor is planned to be constructed as follows:

Flagstones - c.20mm
Screed - 70mm
UFH pipes - n/a
Insulation - 60mm (kingspan, u-value 0.22)
Concrete - 100mm
DPM - n/a
Sand blinding - 50mm
Hardcore - 100mm

Extractor duct will be rectangular, 220x90mm.

Thanks for your help

 

[RandomGrinch]

Hi,

I don't know how helpful this will be!

Naber have some information on their website about their downdraught extractors and some planning examples:

https://www.compair-flow.com/downdraft-with-exhaust-air-this-is-how-it-works/

The ducting is the important part of the system; it's the data sheets for these that include examples of in-floor installations. For example:
https://www.naber.de/en-sf-vro-150-flat-duct-s13365/#size=
(The attached datasheet is from the download section)

Most of the information shows the ducting laid within the insulation layer of the floor.

Does your ducting manufacturer supply any installation examples?

I hope that gives you some ideas!

 

[Flygirl]

We don’t have a ducting manufacturer yet, was hard to know what to search for. I th8nk you’ve found exactly what we need though! Thank you