Replies

1. 
   Guest_ | Jan 28, 1999 09:27pm | #1

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   Generally, areas or rooms that may create odors that shouldn't be distributed around the house won't have return vents. This makes sense to me.

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   Guest_ | Jan 28, 1999 09:43pm | #2

   *Isn't the high pressure created by the fan, in such a small volume area, equalized once the door is opened?

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   Guest_ | Jan 29, 1999 02:56am | #3

   *We generally do not put return air registers in bathrooms, for Odors and humidity.Somewhat on the same line, how do you vent the bath fan in colder climates. I hate to just send warm moist air into the attic, but I also hate to vent the fan through the roof or into the exterior soffit. Seems like cutting a 4" hole to the outside just lets more cold air in. I've talked with our building inspector, but even he can't decide how to vent bath fans. Any one with any strong opinions on venting bath fans ?

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   Guest_ | Jan 29, 1999 03:06am | #4

   *JJ,I have a Fantech exhaust fan in a second story bathroom below an attic. The ceiling vent housing provided by Fantech in the FR100 kit has spring-loaded clam doors in it to prevent backdrafting into the bathroom. I used 4" PVC drain pipe (the lightweight green kind)to duct the vent to the fan, which is mounted near the gable wall, and from the fan to a wall cap (Broan #642)that has a self-closing damper. The ducting is insulated with ducting wrap (foil faced), secured with silver tape. So far, no problems from the attic, and the bathroom stays dry.

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   Guest_ | Jan 29, 1999 03:36am | #5

   *Barry: Thanks for the info. I've read about the Fantech system but never used one, I'll try it the next chance I get. Is it worth the extra $$ ?

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   Guest_ | Jan 30, 1999 12:21am | #6

   *JJ,I think the Fantech is worth the price. It's much quieter than the conventional ceiling mount fan, and it's a powerful draw. I will say that it does still make a sound, and it's a bit unusual -- sort of like a distant wind tunnel sound, probably attributable to its squirrel cage fan design. The ceiling vent is also very unobtrusive. I can't speak to the exact figures involved, but I have to believe that the smooth walled PVC ducting has limited static pressure in the system, so I should be getting close to the rated cfm. I ordered mine, by the way, from Park Supply in the Chicago area at some discount. Their Internet site is . I have to confess that part of choosing the fan was curiosity about the remote fan concept. If some of the Panasonic models approach the Fantech in quietness, I can't see a reason not to consider them.As to the wall cap, I painted it to match the siding and now don't even notice it on the side of the house -- sort of like a dryer vent. I would choose this form of venting over roof or soffit. No one needs more holes in the roof, and I haven't seen a downward exhausting cap that is self-closing like the wall cap. The Broan cap I cited is a bit more substantial than the standard dryer vent. Got mine at the local plumbing supplier, though I would believe the fan source should also have them.On a related note, I hear one level of sound when the furnace is running, and then a different, higher level when the furnace shuts off. An analogous situation is when your vacuum cleaner grabs a bit of carpeting. My conjecture is that the fan is laboring more when the furnace isn't supplying air to the bathroom. The sound returns to normal if I open the door, so widening the floor gap at the door could resolve this problem. I had never encountered this with the contractor quality fans I've had in the past, probably because they weren't drawing that much air, anyway.

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   Guest_ | Feb 02, 1999 07:14am | #7

   *Steve, Thanks for the info. JJFantech site has a worthwhile site for more info:http://www.fantech-us.com/index.htm

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   Walter_R | Feb 04, 1999 05:20am | #8

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   Builder vented into attic at the soffit vents. Roof also has continuous ridge vent. Would think that natural convection would cause air flow from soffits to ridge vent (8/12 pitch roof if it makes a difference). But dumping moisture at soffit certainly appears to be a no-no..

   To eliminate roof penetration.. How about sheet metal enclosure inside attic, mounted at peak, with opening to ridge vent, input from bath fan.
   Would this get the moisture out of attic without
   roof mod? Would still need some form of flapper to prevent backdraft when fan off.

3. 
   norton_jensen | Feb 04, 1999 05:20am | #9

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   I have received conflicting advice on the advisability of return registers in bathrooms. Any advice??