Check with your local code compliance officer as our fair city requires an exhaust fan in the laundry, AND one in the terlit room if there is no window.

Cabot&Row, fair to say that would be true foe just about any town. We're certainly keeping the dryer duct in the laundry, that duct can't be shortened as the washer/dryer stack can't be moved to the opposite wall. Sorry my question has been confusing.

My question is in only in regards to the powder room.

DH wants to install it above the sink, right next to the outside wall, to keep that duct as short as possible.

I think that the bathroom fan should be located right above the toilet.

Who's right?

Why not compromise and get a fan with a flush mount ceiling light and place it in the centre of the bathroom. The duct will be shortened somewhat and it will look like an intended light in the centre of the bathroom.

silken1 - I don't like the quality of light that a flat fan light provides. We're planning on two or 3 spot lights on a rail or track, so as to light the room in general and to specifically direct light to a large piece of art that will hang on the long wall of the powder room.

C&R I guess that's what I needed to hear. Hubby wins this one :-)

C&R, Why does there need to be an exhaust fan in a laundry room?

How often do you think you'll realistically be using the fan in a powder room? We have the same layout with the fan over the toilet. In 15 years, the fan has been used a half dozen times. We do have two other bathrooms to do our do, and prefer the privacy of those rooms. I don't even vent them though. You know that old saying....

We have just one 100 watt sconce in our powder room due to a slanted ceiling over the sink. It's worked out fine for the brief time we're in there.

monikakm - I think C&R meant to say dryer vent with duct, not exhaust fan.

mayflowers - That powder room is very private, it's located through the mudroom and the laundry space (not really much of a room). I know that many people like to masque BR noises by turning on the fan when using the loo at somebody else's house.

As to not venting a full bathroom - that's really a terrible idea. Moisture from showers and baths will accelerate deterioration of everything in those rooms (and behind the drywall). Mold will discolor grout (necessitating a lot more cleaning) moisture will damage your vanity's finishes, and the paint on your walls and ceiling. Over time your insulation turns black from mold behind the drywall and of course moisture renders insulation useless.

Exhaust fans are inexpensive and easy to install. I just don't get it, why would anyone not vent their bathroom?

We vent when showering but not when using the toilet.

We have an exhaust fan in our laundry closet.

Round these parts a vent fan in the laundry room is required. A separate vent is required in the toilet room. Since there is a door, they are considered separate spaces.

Explain to your husband that the vent is not part of the heating duct system, and as long as the duct is insulated, the location in the room is irrelevant from a heat loss perspective. The fan will draw the essentially the same volume of air regardless of whether the duct is 2' or 8' long. You can situate the fan where it makes the most sense or is easiest to install; the center or closer to the toilet would be my choice. There are many innocuous grilles, including ones that can be painted the same color as the ceiling. Besides, how often does one look up at a bathroom ceiling and say: "Wow, that fan grille placement really ruins the aesthetics of this space?

^^ good post

C&R - I believe you live in Texas? Well, Chicago doesn't have the same climate as Houston (thank god). Exhaust fans in the laundry are not required in my burb. And I have to say, I've never noticed that the washing machine raises the humidity measurably. My washer is a front loading HE washer and uses very little water. Never have I ever felt the need for an exhaust in my current laundry. Plus, my new laundry has an operable window. Anyway, it seems to me an odd requirement - don't most dryers essentially act as exhaust fans when they run because they take air from the room and exhaust it (through the dryer) outside?

kudzu9 - my husband agrees with you that a 5 foot long duct does not impact a fan negatively. But most of the time this fan is not running, and during extremely cold weather the duct's air temperature (being essentially open to outside) drops to be freezing cold, and of course the longer the duct, the further that cold air reaches underneath our master bath floor, which is why he'd like to keep the duct as short as possible: we like warm toes :-)

I understand your husband's argument, but it's just not an issue. The duct should not be open to the outside as it should have a damper, regardless of duct length. If the duct is sealed at the joints and insulated, an extra several feet of duct will not have any measurable effect on energy consumption or comfort. I'm a retired engineer and, if he needs to be convinced further, I can do the energy loss thermodynamic calculations for him if he will specify the duct diameter, the R-value of the insulation, the average attic temperature, the indoor temperature, and the two different duct lengths under consideration. Trust me, the only issue is whether you have a damper that seals well, regardless of your duct length.

kudzu9 - The panasonic fan has a built in damper. Does it seal tight? No. There's of course also the damper at the exit. During strong winds (Chicago = Windy City) you can watch and hear this damper getting sucked open and blown closed.

If that is true, it will happen regardless of the duct length, and unwanted heat loss will be almost entrely through air exfiltration, not by conductivity through the walls of a well-insulated duct. Duct length is not an issue in this situation, but, if your husband can't be convinced, then he should put the fan where he thinks he needs to.

kudzu9 - I agree, it's not worth arguing. Thanks also for your clear explanations.

You're welcome. Good luck...