Kair 100mm Round Duct Connector with Backdraught Shutter

Bought this to retro fit in the ducting of a 12v Manrose bathroom fan which, for some reason and unlike its predecessor, came without a backdraft shutter. As other buyers have mentioned, its a tight fit in 100mm ducting and I had to trim the outer central ridge on the shutter to fit it inside the ducting. Used a very sharp paperhangers knife to shave a millimetre or so from the ridge and it now fits perfectly, held in place, just in case, by a blob or two of silicone. Its working well so far: yes, it clatters when the wind blows but that goes with the territory when, as we do, you live in a windy coastal town. Not sure how long it'll last given the wear that the wind will place on the shutter's basic hinges, but Time will tell. Very easy to retro fit if you have the access, so recommended.

I bought this to stop draughts through the extractor duct, which caused the extractor fan to run for an extended period to clear the shower room. Works fine and immediately shows the difference in humidity reduction in the shower room. Only concern is that the build quality isn't great, so when you tighten the clips around the ducts, make sure the flap works freely.

Good design and works at a good price

This works really well, it has a plastic lip half way down which you can shave a bit off to fit inside / in the middle of a 100mm tube. They're hard to get in stores for some reason, but it works really well, as soon as the fan starts it opens, then closes when it's off.

2 main problems: 1. The overall manufacturing quality of the product was not as I would have hoped. The plastic molding is poor with a jagged part jutting out of the flap in an area which could potentially interfere with it's closure. See photo. 2. I found that the flap does not swing freely even before being fitted, and there is some resistance even to gravity. If the product is compressed slightly from the outside then the flap does not swing at all and can be held in an open position. Considering that the movement of the flap will only get worse as the product inevitably collects dust and grime I elected not to fit this product and fitted a competitor product of the same mechanism which seemed immediately better quality and performance. N.B. I did bought a second one of these as I wondered if it was a blip but both were the same and were returned.

Bought this to replace an old one I had that had a spring in it and 2 flaps. The design of the new one seems a lot better as there's less moving parts. It fitted easy enough but I will see how it gets on. In our vents there's eventually a build up of various fluff/dust in the pipes. It's useful to clean these out every few years and this is how I found the previous shutter wasn't working too well and needed replacement. Just need to make sure this new part is fitted the correct way up otherwise it isn't going to work - pretty obviously really though.

I recently bought this backdraft shutter hoping it would stop cold air from blowing back into the house, since my current bathroom extractor doesn’t have one. Unfortunately, the shutter stays open and never closes. If you have a reasonably powerful extractor, I’d avoid this product. I tested it with both a 200+ and a 100+ extractor, and in both cases the airflow kept the shutter fully or partially open. I can only imagine it working with a very weak extractor that doesn’t push enough air to open it completely. Someone suggested adding a screw to limit how far it opens, but the problem persists — it still won’t close properly.

As received, the flap would occasionally stick, probably due to some flash from the moulding near the pivot. After a little bit of moving it around, the problem seems to be solved and I think this will work well and be a good product.

Made of thin abs plastic. I thought they would be more durable for the price. If I didn't need them I would have returned them.

scarsa la tenuta in controflusso, nel mio caso ho risolto con serranda motorizzata con flap dotato di guarnizioni di tenuta ....... che ha ben altro costo rispetto a questa serranda di plastica. piuttosto che niente meglio piuttosto, ma non aspettativi chissà quali prestazioni, per quello che costano un tentativo fatelo, magari per le vostre esigenze sono sufficienti.

Very good

Cumple su función. Se abre al encender la campana y se cierra cuando la apagas impidiendo el paso de aire y olores. En principio correcto.

Perfecto cumple su misión perfectamente, se adapta al diámetro de salida de humos y gases del baño y de la cocina.