Moonshine Posted January 30, 2020 Share Posted January 30, 2020 Due to the layout of the house i am designing, as a bathroom and en-suite are close together there is the potential for both to share the same extractor duct work, which means only one external penetration, which is good. However there vents would need to have some sort of check valve in them so that when the duct was pressured by one room, the extract wouldn't be vented into the other space, does such a thing exist. The extract fans would likely be ceiling mounted, does anyone know if these have one way valves in them? While i am looking at this, i have also assumed that both bathroom and en-suite will use a single soil pipe, which is vented through the flat roof Link to comment Share on other sites More sharing options...
ProDave Posted January 30, 2020 Share Posted January 30, 2020 Operate both rooms with one fan. So when either room is in use an in line fan (after the branch) extracts air from both rooms. 1 Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 30, 2020 Share Posted January 30, 2020 As ProDave said, you can only do this with a single in-line fan, just ensure that you divide the flow rate of the fan by 2, and ensure you get the correct flow rate per room. Link to comment Share on other sites More sharing options...
Temp Posted January 30, 2020 Share Posted January 30, 2020 You might need to build a circuit the performs a logical OR function so that if light switch A or B is turned on power is sent to the fan. I think this can be done using double pole switches. One pole sends power to the light, the other pole sends power to the fan. Both rooms would need to be on same circuit. Will need more cores in the wire from light down to switches than normal. Link to comment Share on other sites More sharing options...
Moonshine Posted January 30, 2020 Author Share Posted January 30, 2020 1 hour ago, ProDave said: Operate both rooms with one fan. So when either room is in use an in line fan (after the branch) extracts air from both rooms. That would be good, though one potential snag is the potential fan noise from the en-suite in the master suite late at night, if the bathroom is used. Link to comment Share on other sites More sharing options...
Mr Punter Posted January 30, 2020 Share Posted January 30, 2020 I have done this using two iCON 30 mixed flow fans. They have an iris to prevent backdrafts so you don't get air from the other bathroom. 1 Link to comment Share on other sites More sharing options...
mm289 Posted January 30, 2020 Share Posted January 30, 2020 As with @Mr Punter we have a master bathroom and an ensuite shower room next to each other. BC wanted fan in both rooms so we fitted extractors with one way valves/flaps, the pipework from which ran into a t piece in the loft before exiting under eaves. BC seemed happy and I haven't noticed any backdraft issues? Cheers, MM 1 Link to comment Share on other sites More sharing options...
joth Posted January 31, 2020 Share Posted January 31, 2020 On 30/01/2020 at 12:01, Moonshine said: i have also assumed that both bathroom and en-suite will use a single soil pipe, which is vented through the flat roof Soil pipes don't tend to require open venting these days? Use a Durgo/AAV instead https://www.designingbuildings.co.uk/wiki/Air admittance valve Link to comment Share on other sites More sharing options...
Moonshine Posted February 1, 2020 Author Share Posted February 1, 2020 9 hours ago, joth said: Soil pipes don't tend to require open venting these days? Use a Durgo/AAV instead https://www.designingbuildings.co.uk/wiki/Air admittance valve Interesting, and the use of one of these would negate the need for a penetration through the flat roof. I presume this could be put on top of the SVP stack within the boxed in section, as long as there was a small vent to within the SVP boxing, like below https://www.screwfix.com/p/map-vent-fixed-louvre-vent-with-flyscreen-white-229-x-76mm/5104d Link to comment Share on other sites More sharing options...
joth Posted February 1, 2020 Share Posted February 1, 2020 Like most things, I only know what I learnt about them on here The horizontal main drain needs separate venting somewhere. Ours is planned to be in the attached garage, which I'm now a bit concerned will make that stink. Etc https://forum.buildhub.org.uk/search/?&q=Aav 1 Link to comment Share on other sites More sharing options...
ProDave Posted February 1, 2020 Share Posted February 1, 2020 On 30/01/2020 at 12:22, Temp said: You might need to build a circuit the performs a logical OR function so that if light switch A or B is turned on power is sent to the fan. I think this can be done using double pole switches. One pole sends power to the light, the other pole sends power to the fan. Both rooms would need to be on same circuit. Will need more cores in the wire from light down to switches than normal. My prefered method is a 2 gang switch, one for the light and one for the fan. Then it becomes a whole lot simpler. And when you go for a night pee, you don't have to turn the fan on. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now