2 bath fan exhausts, one roof vent
Does anyone have any solid experience here. I have been meaning to try the fantech options for awhile but the elctricians installed the conventional fans. We have 2 bathrooms close together. I would have thought that you could join them at a y with a baffle in it and go out one vent. Suppliers are looking at me funny. Is there no such Y? why?
arthur
Replies
Not a good idea, since it may force the exhaust from one fan to travel throught the ductwork and the other fan back into the dwelling space.
Mike Hennessy
Pittsburgh, PA
Mike I realize that. That is why the 'baffle' it is surely not that complicated to have a flap inside that only allows flow out.. out the duct with fan pressure to flow out. In other words it stops air from flowing back down to the other bathroom fan. ridge vent is a great idea.. its a pity this has no ridge vent..thanksarthurhttp://www.thesmallbuildingcompany.com
Arthur
I connect mine to the ridge vent. No roof penetration,
Chuck S
Sure there is. A proper exhaust system will contain a baffle even if it is a single unit.
First link contains a baffle....scroll to third image:
http://www.fantech.net/accessories1.htm
Second link "Y" connection......4th image down:
http://www.fantech.net/accessories3.htm
J. D. Reynolds
Home Improvements
I did this on my bathrooms about ten years ago and it's worked fine so far. My bathrooms are back-to-back and the fans are only about eight feet apart.
Mine exhaust thru a gable end and I used a 4" "Y" fitting at the wall penetration in the attic. My theory was that reverse air flow would be minimal since there would be far less resistance to the outside than back down the other duct.
I've never seen any hint of a backflow issue thru the non-running fan.
AFAIK if the fans you installed have built-in dampers, then you can wye them together and use one outlet without a problem. I just installed two Panasonic bath fans in two adjacent rooms and joined them together in the attic--it works fine with no backdraft from one fan to the other. If you really want them you can buy inline backdraft dampers--they're about a foot long piece of pipe with a damper inside, and you install them into the line as needed.
You might want to look into the powered dampers used in zoned heating systems. The switch in each bathroom could send power to the fan and to the normally closed damper on the duct to that bathroom.
George Patterson, Patterson Handyman Service
that was very helpful. I thought i was lsoing my mind. When you go to your supplier; be it lumber yard or in this case mechanical supplier and ask for something simple like this .. its irritating when some you ng guy at the counter just says 'no there is no such thing' and when you explain again what you are trying to achieve he still answers that they dont have one. .. :P wont give it a thought.. thank you all very much for your help..arthurhttp://www.thesmallbuildingcompany.com
This damper section might work. You could integrate it right below the "Y" so the joining ductwork won't flow through the junction and down the main duct.
http://www.energyfederation.org/consumer/default.php/cPath/86_744_546
Justin Fink - FHB Editorial
Your Friendly Neighborhood Remodelerator
I have seen advertisements in the magazines for one exhaust fan to vent up to 4 bathrooms and it seems that they have to intersect somehow. If they intersect prior to the fan there can be no back draft but I dont see how it would pull enough cfms
-worth exactly 2 cents!
I have dampers on mine. Three fans one vent. I first had it under the ridge vent but it covered my plywood with mold.
I was refering to the units with one fan and the bathroom vents connect to it, maybe I am not understanding the advertisement in the mag correctly.-worth exactly 2 cents!
If they intersect prior to the fan there can be no back draft
Says who?
but I dont see how it would pull enough cfms
The unit needs to be sized accordingly is all.
J. D. ReynoldsHome Improvements
IF they intersect prior to the fan and the fan is blowing it out how is it going to travel against the fan?
-worth exactly 2 cents!
I see what you're saying.....I meant a backdraft of air from the extrior, when fan is off.
J. D. ReynoldsHome Improvements