2 bathroom exhaust fans vented together, mold problem
bcon268
16 days ago
Featured Answer
Sort by:Oldest
Comments (14)
Related Discussions
Bathroom exhaust fan installed in the floor, anyone?
Comments (13)Babka: ha. they (fixtures) are vented to the space above, (which is under the stairs), not to the outside - which is against the code, I know that much. I guess they (whoever added this bath) ran into the same problem with venting fixtures as we are facing trying to figure how to vent the exhaust fan. and maybe that's why there is no exhaust fan to start with. The bathroom is under the staircase whichi s in the middle of the house, and there is space directly above it because the ceiling is short. But then the ceiling height changes as you go to any neighboring room (the rest of the house around has much higher ceilings). Basically, you can put the duct vertically through the ceiling above the bathroom, but then as you turn it 90 degrees towards in the direction of any outside wall, it would have to come out through the wall of any room around, not in the ceiling above the rooms. And if you try to go higher with the duct so that the turn is at the level of the over-the-ceiling space for these rooms, then the duct would have to come out through the staircase! Hard to explain, but I hope you go the picture. Also, even if we could somehow get the duct to the space over the ceiling of any adjacent wall, then we still can't open up that high ceiling to run the duct further because it has some fancy beams and moldings (house is over 100years old) so we cannot touch the ceiling. That's why I wrote "absolutely no way" for the ceiling route Unless, as somebody above suggested, we place the fan in the ceiling, but run the duct through the wall down to under the house (actually through the under-the-stailrcase part as the stairs go down). But as far as I understand that comment, we will have to install some inline fans in the duct to keep the air moving down......See Morebathroom exhaust vents
Comments (13)Personally I think the fewer penetrations through a roof the better. I also don't see anything inherently wrong with venting two bath fans through a single roof opening. Even if both are on at once, probably the worst thing that will happen is that they back pressure each other and they don't vent quite as efficiently. Both of my bath fans are vented through the same soffit vent....See MoreDo you need a bathroom exhaust fan?
Comments (25)If you're not trying to be 'defiant' of our reasoning, you're certainly trying to convert us to your way of thinking, and I don't think it's going to happen. Clearly you are not open to this idea, but others may at least consider it. So far the inspectors have not said anything. I consulted with two of them, the city engineer, my contractor, and fan suppliers before doing it. Firstly, I'm not going to contradict a building code, especially when there's no discernible logic (ok you disagree but fail to impart what actual advantage your system offers) or advantage to it. I'm not going to run to the library immediately to check the code, but I do get there reasonably often and will check. Again, the inspectors who are familiar with the code are okay with my installation. It could be that a fan is not required simply because I have ventilation into the room via the AC ducting and/or a window, so whether I have a fan in the room is my call. You mentioned your area does have mould issues....(as do all areas I guess) - your system is particularly unwise due to that. You are creating an unnecessary hazard. There seems to be no mold issues in the southwestern deserts or the Rocky Mountains. Our weather is heavily influenced by the Gulf of Mexico so we have humidity in the summer. I don't think it is going to be a problem but is certainly is an issue. Definitely not a hazard. You may even have created a fire hazard You're being alarmist. Explain to me how my house catches fire because the bathroom doesn't vent to the outside. There are a couple advantages to my system. First the fan draws only dry air into it. This keeps the wet dust from collecting on the fan blades and reducing the fan efficiency to near zero in a few months. Second, the fan is mounted 24 inches above the floor in the bedroom. If I need to clean it, which I doubt I will anytime soon, its right there at knee level instead of overhead on the ladder. Third, the air at 24 inches is blown up to the ceiling in the adjacent bathroom 9 inches down from the 9-foot ceiling. As you pointed out, warm air rises. My system blows relatively cool and dry air in a the ceiling height to thoroughly mix the warm/moist air with cool/dry air to get a more uniform air temp and moisture throughout the room. Fourth, air sucked into a fan is only sucked extremely locally. Without a few classes in aero I can't really get into how that works, but you'll notice the exhaust of a jet engine, or even an electric fan for that matter, can be felt much farther away from the blades than the intake air induction can be felt. You have to hold your hand directly to the back of a fan to feel any air intake at all. My system, even with a diffuser at the opening into the bathroom, blows the air into the room hard enough that I can feel it against the far wall, thus ensuring thorough air stirring and mixing. Fifthly (?), in the winter humidity is not a problem here. In the summer it can be if your AC is not properly designed. Mine seems to be but this room has not endured an entire summer. Actually spring is slightly worse for humidity because the humidity is up but the temps are not warm enough to trigger the thermostat. In the summer the AC runs day and night as the outside temps sometimes don't come down into the 80s for several days at a time. It's rather like 'vacuuming' or should I say reverse vacuuming, a room by blowing it all out with compressed air. There may be something about that system you like, but you're just taking the dust from one room (read humidity and bathroom smells) and spreading it throughout the rest of the house. And your vacuum system sucks dust in from outdoors and blows it all over the house. Which is better - the dust you already have indoors or the new dust your vacuum system is sucking in? I knew which fan you were talking about, but I was way off on my house fan power specs. Apologies. I'm not sure what model of blower I was looking at but mine is 3/4 horsepower - more like under 500 watts versus the 750 watts used by my directed fans. If one of my little fans wears out, I have backup. If my furnace fan wears out, it's a service call and a $12,000 AC system (mine is ready to be updated). Your bizarre method and logic may make the condensation evaporate more rapidly (or so you may think) because you are encouraging it to evaporate I guess into a larger area, however, that capacity would diminish over time, since the overall humidity will increase to the point of what is it - equilibrium? Where the air will hold no more moisture, and condensation begins to reform. This is where the structural damage sets in, mould forms and it becomes an unhealthy environment. From a heat transfer point of view, you need to watch your terms better to make that make sense but I think I know what you were trying to say. Still, the last sentence is the important one. The humidity increase from a shower is unlikely to saturate the 18,000 cubic feet of air in the house. However, this is exactly what I'll be looking for in the summer. These bathrooms are at the far end of the house. The concern is getting that air moved out of the confines of the bedrooms and out to the AC air intake in the living/dining rooms. I don't think it will be a problem in the summer with the AC on all the time, but we'll see. I'm more afraid of freezing my butt off in the shower with all that dry air coming in on me. I may have mentioned that I do not get any condensation in my bathroom now and I do not get any even when the fan is off. The reason for that is not clear. I'm working on the theory of massive tile heat sink where the moisture is actually condensing on the cooler tile but there is so much tile that I'm not noticing it. But there is never any fog in the bathroom and no condensation on the mirrors. Ceiling fans may have their drawbacks and I don't love cleaning them either, but I think I'd prefer them to a bunch of fans sitting around on the floors Clearly I'm not going to change your mind on that either but I have convinced several friends to use floor fans, especially in the winter, to mix the hot air at the ceiling with the cold air on the floor. Suddenly my short friends can get warm and my tall friends don't have cold feet. If the thermostat is at 5 feet off the floor and you're 5 feet tall, you live in a world where all the heat is above your head no matter what you set your thermostat to. But if you're six feet tall or taller, your face is always hot and your feet are always cold. With the little fan on the floor pointed at the ceiling behind the sofa, the air mixes in the entire room and everyone is comfortable. Everyone I demonstrate this effect to is amazed. A ceiling fan can be reversed and pointed at the ceiling, but you get into the problem again of the air intake being at 8 feet off the ground blowing air up to the 9-foot level. You really have to have the fan honking to blow that air to the walls and down. Then people seem to complain about the wind in the room. My little fans simply punch a localized hole in the thermal layers and mix them up. I keep ignoring the indelicate subject of bathroom odor, because that does not seem to be a problem in my household. It must be all the lard in the tamales down here ;-) Actually my wife pumps the veggies and fruit into us - I'm not a dietitian. Sorry I'm getting so wordy. Maybe this will stop now that we realize we're not going to change each other's minds....See MoreBathroom exhaust fan problem - please help
Comments (8)Thanks for your thoughts. The vent levers to the outside wall were opening fully when the fan was on, thus eliminating the possibility of 'stuck levers' or any thing disconnected as being the problem. So, I called Broan and spoke with a man who said it sounded like the motor wasn't doing it's job and in spite of the fan being out of warranty, he was very generous in his offer to send a new motor at no cost. I'm a Broan fan for life as a result. On Monday, our handyman is coming to install the new motor and use spray foam around the opening to the attic which should eliminate the 'attic smell'. I think that sealing up this gap will also improve the fan 'draw'. I can always count on my Gardenweb family to come to my rescue ~ thanks for your time ! gardening annie...See Morebcon268
16 days agobcon268
15 days agobcon268
13 days ago
Related Stories
SMALL SPACES5 Solutions to Small-Bathroom Problems
Whether your room lacks a separate shower, adequate storage or a sense of spaciousness, there are remedies at hand
Full StoryBATHROOM MAKEOVERS2 Compact-Bathroom Makeovers, for Her and for Him
She likes warm and light; he likes bold and graphic. A designer helps both of them get what they want
Full StoryMOST POPULARHow to Get Rid of Household Mold
Find out how to work with a pro to stop mold from damaging your house and health — and how to prevent it from forming
Full StoryDISASTER PREP & RECOVERYHow to Combat Mold in a Flooded House
Before you rebuild or restore your water-damaged home, take these steps to keep mold at bay
Full StoryREMODELING GUIDESBathroom Workbook: How Much Does a Bathroom Remodel Cost?
Learn what features to expect for $3,000 to $100,000-plus, to help you plan your bathroom remodel
Full StoryBATHROOM DESIGN10 Bathroom Trends From the Kitchen and Bathroom Industry Show
A designer and his team hit the industry’s biggest show to spot bathroom ideas with lasting appeal
Full StoryFUN HOUZZThese 7 Bathroom Habits Could Save Your Relationship
Kick the ‘ick’ from your bathroom to prevent another argument about mold in the shower and beard hair in the sink
Full StoryBATHROOM DESIGN8 Narrow Bathrooms That Rock Tubs in the Shower
Not a fan of shower-tub combos or of ditching the tub altogether? Check out these 8 spaces with tubs in the shower
Full StoryBATHROOM DESIGN12 Must-Haves for a Designer’s Dream Bathroom
If he had his way — and a rich person’s bank account — here’s how he’d put together his ideal bathroom space
Full StoryBATHROOM DESIGNBefore and After: 5 Bathrooms That Rock Wallpaper
See how wallpaper adds pattern, texture and pizzazz to these recent bathroom makeovers
Full Story
chispa