MVHR cooker hood idea

[Adsibob]

We’ve decided to cut a gaping 6” hole in a wall to vent out our cooker hood. I will post a video when I next cook steak, but basically the way we designed our recirculating was a f&@king disaster which anyone with any basic physics knowledge would have known wasn’t going to work. 
so that we don’t completely ruin our very effective airtightness, can anybody recommend an external vent to cover the hole which pretty much self seals when not in use? It didn’t doesn’t have to fully seal, but something that prevents a noticeable draught would be good.

[dpmiller]

If the duct runs vertical for a bit, there are good sealed gravity flaps available. That's the route I took. Motorised damper is another possibility.

[Adsibob]

13 hours ago, dpmiller said:

If the duct runs vertical for a bit, there are good sealed gravity flaps available. That's the route I took. Motorised damper is another possibility.

Thanks @dpmiller, don’t suppose you could post a link to such products?

[dpmiller]

something like this

https://www.ebay.co.uk/itm/255271428161

as the rubber seal works commendably well. I did however glue a washer onto each flap, to weight it a bit more and ensure it *only* opened with the strong flow from the hood.

 

For motorised, you're probably looking for a spring-return fire damper unit, as the cheap chinese motorised units require an odd switching logic that would be difficult to integrate with our way of wiring things, IMO.

[Rossymcg]

On 06/02/2022 at 20:49, hb1982 said:

 

I hope the attached makes sense to you.

A standard hood extraction of 150l/s (good quality 900mm hood) is not small for an air tight house. 200mm duct is recommended, 150mm is the absolute minimum. 

 

 

Good idea. I'm investigating the idea of fitting a heat exchanger in the mix. You think it could work? One question the belimo, is there an automated switch that detectes the pull of current through the cable feeding the hood and switched it on?

TIA

[JohnMo]

People do over think stuff. With MVHR, just do a recirculation hood. The times you actually need to use them is few and far between. Cannot now remember the last time the hood got switched on. MVHR does most of what you need on its own 

 

Keep it simple

[Marvin]

6 minutes ago, JohnMo said:

With MVHR, just do a recirculation hood.

This is what we do. The outlet from the cooker hood which is above a kitchen unit also directs the exhaust towards the extraction point in the kitchen of the MVHR. However I think it depends what sort of cooking and how much you are doing as to the effectiveness of this.  The extractor hood does not take the temperature or humidity away and collects grease....