RKKI Backdraft Shutter 4 inch Inline Extractor Fan Backdraft Shutter Self Closing, Weather/UV Resistant Plastic, 100mm

Reading other reviews, this is an INLINE vent, not an outside vent, needs to go inside the vent tube. I added some green tape to fill the gap between the blades and the edge of the vent frame. I took off the vent tube from the extractor, installed the backdraft shutter, placed vent tube back.

I fitted this backdraft shutter to my kitchen extractor to prevent cold air from blowing back into the kitchen from outside. Unlike some other reviewers, I found mine fitted snugly into the fan exhaust adaptor (it must be a different size of fitting?) & I also applied some PVC tape around the join. This arrangement works very well, and you can hear the faint but reassuring sound of the shutter closing after turning off the extractor. However, it does clatter on windy days, and I've taken a star off for this! I'm not sure what the solution is- I've tried different types of shutter, both at the fan exhaust end and at the outlet end, but all of these options still clatter when it's windy! I also tried putting some thin strips of self-adhesive rubber foam along the mating surfaces of the valve, and this does deaden the sound to some extent, but it's still there...

This thing works well, I think a few people have missed the main feature - it fits INSIDE a round 100mm vent duct/pipe. Its deliberately designed to be a loose fit so get some foam draft excluder tape (5mm max thickness) and put it around the outside. That will create a nice snug fit, just push the shutter gently into the pipe. Switch on the extractor and check its in the right way round - job sorted.

This purports to be for 100mm ducting. It isn’t. It is 95mm and thus undersized. The only way you can make it work is to create a means of holding it in place inside the ducting - by say, sandwiching it between tow bands of adhesive foam insulating tape. Very poor and would not recommend.

It works, the wind coming in through the utility extractor fan was not worth having the heating on but this has stopped it, got another to put in upstairs bathroom.

Easy to fit to existing extractor fan.

Great, the draft that used to plague us are a thing of the past, now life is great

This backflow preventer is not suitable for use in a 100mm pipe. It is approximately 95mm across and so can not be "installed by pushing it into the ventilation pipe as far as it will go". Additional seals or smaller piping would be needed to make use of this item.

Second achat de ce produit 100% pvc

Meccanismo molto semplice, è una valvola di non ritorno con una molla che richiude 2 sportellini. La molla è molto debole quindi è necessario posizionare la valvola leggermente inclinata così che la forza di gravità agevoli la richiusura. Mi sembra molto difficile utilizzare una valvola di questo tipo in fori verticali, ma per quelli orizzontali va abbastanza bene. L'ho inserita nel classico tubo arancione da 10cm di diametro ed è entrata agevolmente. Visto il prezzo mi sento di consigliarla. Non aspettatevi una valvola a tenuta stagna ovviamente, un po' di aria passerà comunque.

Funktioniert. Habe ich einfach mit Heißkleber an den neuen Ventilator geklebt und mit Lüftungsklebeband zusätzlich abgedichtet. Montage sollte senkrecht vollzogen werden. Ein Hinweis mit TOP oder oben wäre gut. Sonst öffnen die Klappen nicht wie gewünscht. Auch wenn es jedem klar sein sollte - besser wäre das. Allgemein könnte es auch billiger sein. Aber egal. Funktion und Verarbeitung ist gut.

Hace su función a la perfección.

Do not fit in pipe 100. Is too small