From an energy standpoint, as well as a moisture standpoint, your husband is doing the wrong things. First, you are losing more heat with the window open than you would by simply running the fan; even if the door is closed, all the solid surfaces of the bathroom are losing heat out the window, and then will draw heat from the rest of the house to come back up to ambient temperature once the door is open again. Second, the cold air coming in the window condenses the warm, steamy water in the air and makes a mess, as you've observed; further, since the vapor drops out of the air as it's condensed, it can't be evacuated and makes the exhaust fan ineffective. Keeping the window open is fighting against everything you want to do. Tell your husband he's been outvoted and to close the window in the winter.

I'm not an expert, but from what I've read, you're right, that's not going to be enough. If you haven't already, why don't you ask on some of the GW building forums also to improve your chances of getting this answered before the contractor gets there tomorrow :) Here is some info I've saved from our master bath remodel. Hope you find it helpful. If not, maybe someone else will :) Monica Venting exhaust If he is venting the exhaust into the attic air space, that's bad. Even if there are attic vents (normally gable wall louvered vent panels, or a combination of soffit and ridge vents) in the attic that allow air to move through the space. If he has the end of the duct just pointing at the attic gable vent, that's no good either. The goal is to get the moist air outside the house, not to dump it directly in the attic, or dump it near the gable vent, where air currents can keep the moist air in the attic. If he is bringing the duct up into the attic, then continuing the duct laterally and running the duct out through the gable wall and installing a vent cap out there, then that's a good thing. I prefer the vent to be rigid metal instead of the flex duct, and I prefer the lateral run to be sloped slightly lower as it runs towards the gable wall. I use aluminum tape to tape all seams in the duct, taping both the seam that runs the length of each piece of duct as well as around the circumference where two pieces are joined together. This way if there is any condensate in the duct it runs out the vent instead of pooling and/or running back down into the fan. It's a small, but important detail. Personally, I prefer as few holes in the roof as possible. Mongo Rigid ducts are fairly easy to slope, they just need periodic support along the horizontal run. In a attic it can either be hangers coming down off the rafters, or wood scabbed to the floor joists running up vertically. Oooooh. I didn't think of a brick house. Brick can be more difficult, but it is done. Still with brick, it might actually be easier to go out the roof, but hopefully only if it's on the back side of the house. I'm not certain if venting to the outside is required by code in your area, you could give your local building department a call. If it is a code requirement (it is in my locale), then it should have been included in the scope of the work. After all, he should bid the job and complete it to code, right? Then again, I wouldn't want a ticked off contractor cutting a hole in my brick wall or in my roof while angry and while trying to do it on the cheap.

I agree. back draft damper installed correctly...where it actually closes when fan isn't in use. I sometimes have to mastic tape a penny or two to the damper so that it closes properly. but then I'm using the mastic tape to attach the damper to the housing, venting to the damper & to close that huge cut in the ceiling that the cover of the fan covers. I'm always amazed at the number of bath fans I see in my inspections with NO back draft damper. in new construction I usually pull the dampers out of the trash.. go figure! there are some really nice bath fans that are very quiet on the market. not too long ago I installed 3 Broan bath fans. not as expensive as the Panasonic whisper quite, but as quiet. I find people often don't use the bath fan because they are so loud...and the bath fan should be run for 20-30 minutes after shower to remove humidity. here in La. we need all the help we can get with keeping (RH) Relative Humidity down! best of luck

mike -- Don't know that we will need a timer. It's just DH and I -- retired -- can remember to turn it off, I think. BTW, how long should it run after a bath or shower? energy rater -- The specs say the backdraft damper is within the 8" duct connection portion of the fan, not whether it faces in or out. I need to ask that they face it away from the fan itself, right? Or are you saying the damper should be not at the fan, but at the soffit? The bath is on the NW corner of the house. Air and moisture will go UP through the bathroom ceiling into the fan, ACROSS about ten feet of attic floor, then out a West soffit. Is it at the soffit that you want metal-flex flaps? Does moisture acclumlate there? Drip outside the exterior wall? (Yeah, where DOES the water go?) I see round aluminum-looking flex-ducting in the attic. Is that what I should expect to see on this install -- not hard metal ducting like a forced air furnace? Is this capacity appropriate? I want to eliminate excess moisture, but don't want to be taking baths or showers in a wind tunnel! (It is meant to run *while* one bathes and a short while afterwards, right?) Is a sone rating of 1.7 good? Is Broan a good brand? This installer is also going to correct three other, smaller bathroom exhaust fan ducts that now empty INTO the attic instead of outdoors. Price is $900 all in for Broan unit and all work. He says it will take about four hours. We are north of Chicago in a high-*address tax*-suburb, as my DH terms it. Thanks so much for your time and trouble. Much appreciated. I'm probably overly concerned, but we keep finding faults (like these fan exhausts) in a house that passed city inspection when it was built only 10 years ago. I'm sure it was not code to vent into an attic!