Ducting for cooker hood

[Thomas C]

I am trying to figure out best way to duct the cooker hood. Last autumn I had combi ripped out for air source heat pump leaving 5" hole in side of wall. Also I had new windows, before that kitchen window had a built in extractor, new window in kitchen does not have hole for extractor. Cooker did not have any ducting before as it was not required by law (due to extractor in window), with absence of window extractor that cooker hood ducting to outside is now required. Mid terraced house so cannot vent out directly behind cooker.

I had planned to use the hole from old combi to vent cooker hood out of that. But I cannot work out how to do it neatly. Cooker hood pulls out, looks like small cupboard door on top, 5" hole centrally at top ready for a vent pipe. One possibility is to use rectangular ducting mounted onto rear wall just above cupboards then bring it out through old combi hole, that would create a lot of cold surface within kitchen though with likely condensation issues. I had also thought of running it through floor between beams (they run towards rear wall) and then venting out of 1st floor loft through facia board. If too difficult might just replace glass in window and put another window extractor back in.

See photos attached, the cooker would be 2ft in front of cupboard in bedroom if go the floor route.

Love to hear any ideas how to solve this satisfactorily.

 

[RandomGrinch]

Personally, if I could find matching kitchen units, I would try and mount an extra cupboard in the gap where the combi was; then run 4" ducting above the units and out of the hole.

A matching cornice on top of the units could then hide much of the ducting, from a normal viewing position.

With a decent flapped vent on the exterior, I don't think condensation would be a big problem.

...and the junction box could do with being sorting out!

 

[jj4091]

I'm guessing your cooker hood is the recirculating type so you need to check that you can fit an exhaust manifold in the top before anything. Once you have established it is feasible then have a look here for ducting and accessories. https://www.tlc-direct.co.uk/Main_Index/Ventilation_Index/index.html Some flat trunking fitted to the ceiling or top of units and across the gap with the elbows or adapters as required.

 

[Thomas C]

Thanks for suggestions and comments. Will look into both approaches and make a decision.

Yes, I agree that junction box really needs replaced also, its on the todo list. Combi kind of hid it before.

 

[Thomas C]

I thought I would update this post with final results. In the end I could not take ducting through the 1st floor beams so underslung some flat rectangular ducting on the kitchen ceiling and vented out of the old 127mm combi hole already in wall. Then boxed around. Photos attached.

I would have liked to avoid using plastic screw caps on the boxing, if anyone has anyone has an alternative to hide the screws but retaining ability to dismantle boxing glad to hear any. I did not use tacks for that reason and also did not trust the plaster board fixings to absorb hammer blows.

By the way I found Manrose's ducting systems horrible to work with, tolerances all over the place and had to do many hacks to get everything to hold together.

 

[jj4091]

You've done a nice job of that but I cannot tell what material you have used or how much weight you need to hold when you talk about fixings. But if you look here there are many choices and I think my preference would be for the magnets from Am*z*n which are amazingly strong.

invisible fixings - Google Search