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35 votes
Accepted

Bathroom exhaust fan without duct

Is this a big problem? I assume the fan has been like this for 15+ > years. If it is, I will look into getting a duct there, which is complicated by the inaccessible attic space. Moisture in the ...
Ack's user avatar
  • 5,729
29 votes

Is it a bad idea to install a bathroom vent in a drop ceiling without external exhaust?

You need to exhaust the bathroom via a duct in the ceiling void and through an outside wall. You can't just push bathroom air into the void ... it will cause mold up there and push humidity and ...
jay613's user avatar
  • 38.9k
25 votes

Does a portable fan work for drying the bathroom?

You need a dehumidifier. https://en.wikipedia.org/wiki/Dehumidifier If there is no way to blow the humid air out, run it thru a dehumidifier. You can keep it in the bathroom running on a timer or ...
Willk's user avatar
  • 6,593
22 votes

Does a portable fan work for drying the bathroom?

When the things in a bathroom dry the water is not simply disappearing, rather it is converting from liquid you can see and feel on the surfaces and towels into vapor in the air. In other words, ...
Greg Hill's user avatar
  • 30.8k
19 votes
Accepted

How can I offset 6" ducting by just a few inches?

30 inches of height? 3 inches of offset? You need to learn how to use multi-section rigid duct elbows, which can be rotated to be considerably less than the 90 degrees you buy them at. You have plenty ...
Ecnerwal's user avatar
  • 217k
18 votes

Will it cause problems to shower without the exhaust fan and only turn it on afterwards?

Condensing water is never good. The vapor will creep in places where it may not quickly evaporate once it has condensed. It will condense easily but dry slowly in cold places and badly ventilated ...
Peter - Reinstate Monica's user avatar
16 votes
Accepted

Trying to replace bathroom vent, but housing is stapled to the rafter

You've already pretty well mangled the housing and you're planning on replacing the whole thing anyway, so just go to town hacking at it. A pry bar, a hammer, a pair of tin snips, and some sturdy ...
FreeMan's user avatar
  • 47.4k
15 votes
Accepted

Can the exhaust duct of an ERV vent *into* the garage?

I am sure it would be against code. If it isn't always running and your ERV doesn't have a damper on the exhaust then you've introduced a nice path for CO to enter from your garage into your house. I'...
Fresh Codemonger's user avatar
15 votes
Accepted

Brand new bathroom fan appears to be spinning the wrong way

This is a centrifugal fan. The fan blades can be straight, curved towards spinning direction or against spinning direction. This will affect the noise level and efficiency of the fan, but the ...
jpa's user avatar
  • 1,514
13 votes

Bathroom fan fluctuates in power when using countdown timer switch

There are actually two problems, and they are related: Low Power Fan First I found a customer review on the Lowes web site that said: I gave this only three stars as no where on packaging or ...
manassehkatz-Moving 2 Codidact's user avatar
12 votes

Trying to replace bathroom vent, but housing is stapled to the rafter

A small prybar, cold chisel, or a screwdiver you don't like much (this is screwdriver abuse) can be driven under the staple to get it moving. There appears to already be space there. Even a large nail ...
Ecnerwal's user avatar
  • 217k
12 votes

How do I screw through a metal bathroom fan box to affix it to the joist?

Almost any wood screw. It takes only say 3/4" of penetration into a joist to secure such a housing. Thread type doesn't much matter. Diameter doesn't, either, though thinner screws will go in ...
isherwood's user avatar
  • 139k
12 votes

Is it a bad idea to install a bathroom vent in a drop ceiling without external exhaust?

The point of a bathroom exhaust fan is to pull humid air out of the bathroom. That humid air must go somewhere. If that "somewhere" is another interior space, you're just moving the ...
Ilmari Karonen's user avatar
10 votes

Bathroom fan and clothes dryer share an exhaust duct

The only good solution here is to run independent duct lines to the exterior, as should've been done initially. It's a violation of codes for good reason, as you've seen. Both ducts should be rigid or ...
isherwood's user avatar
  • 139k
10 votes
Accepted

Bathroom fan fluctuates in power when using countdown timer switch

Take it back and get a different timer The stock Lutron MA-T51 does not need neutral; however, it accomplishes this by trickling power through the load. This is fine for large loads, but for low ...
ThreePhaseEel's user avatar
9 votes

Why are my bathroom light and fan wired to the same switch?

Many apartment owners wire the fan and light to a single switch. The reason I have done it is to limit moisture build up. Not all renters are responsible enough to turn on the fan while using the ...
mikes's user avatar
  • 11.4k
9 votes
Accepted

What tool/process do I need to remove this bathroom exhaust fan from motor?

The "small hole on the inner side" is a set screw. You will see that it lines up with the flat surface milled into the side of the shaft. You must unscrew it with a hex wrench, aka an Allen ...
A. I. Breveleri's user avatar
9 votes

How did this ceiling exhaust fan get stuck on (and why did disconnecting this wire fix it)?

The logical answer is the "mystery wire" is from a 3way switch somewhere in the room, ( or possibly in an adjacent room) that someone switched on. The fan timer probably replaced the other ...
RMDman's user avatar
  • 30.7k
9 votes

Can the exhaust duct of an ERV vent *into* the garage?

Unless your ERV also exchanges humidity, you are putting relatively humid air into the cool space of the garage. Even in my dry climate (Alberta, 16" of precip/year) the aphorism "rust ...
Sherwood Botsford's user avatar
8 votes
Accepted

How can I remove stripped screws in a bathroom exhaust fan motor bracket?

Once you have the assembly out of the ceiling and on your workbench, you'll probably find that there are hex nuts on the other end of those screws, possibly with thread sealant. If removing the motor ...
MTA's user avatar
  • 11.4k
7 votes

Will it cause problems to shower without the exhaust fan and only turn it on afterwards?

Not a big problem but moisture is almost never a good thing in a house unless you live in a very dry climate. Why not turn the fan on first thing? In addition to mildew, moisture isn't good for ...
HoneyDo's user avatar
  • 8,764
7 votes

Bathroom exhaust fan without duct

Venting into an attic is terrible in North American climate zones (6,7,8 in linked map below); less so in arid southern zones (1,2). This will give you a sense of how bad this might be. Beyond that, ...
Aloysius Defenestrate's user avatar
7 votes

Bathroom exhaust fan without duct

Ack's answer is very good, so I won't repeat what they wrote. I will add that molds can definitely create a significant health hazard. I would get the attic inspected for the presence of hazardous ...
End Antisemitic Hate's user avatar
7 votes
Accepted

How should I connect misaligned round ducts inside a cabinet?

I see no reason you couldn't use a short length of 7" flexible duct. Obviously, a long flex is a bad idea because it restricts flow, but for that few-inch offset, flex will do you fine.
Chris O's user avatar
  • 6,795
7 votes

How do I screw through a metal bathroom fan box to affix it to the joist?

There exist "self drilling" screws that have a hardened drill point for piloting their own holes through metal, but these tend to have threads that are too fine for grabbing onto wood ...
popham's user avatar
  • 10.4k
7 votes

Brand new bathroom fan appears to be spinning the wrong way

That's a shaded-pole motor. It generates a rotating magnetic field by "shading" part of the rotor poles with copper rings (ends visible beside the rotor and there should be a matching pair ...
Transistor's user avatar
  • 1,067
7 votes

What does "attic access required" mean in the context of a bathroom exhaust fan?

For the panasonic fan I recently installed in my home, it means that the method of installation requires screws to be driven into a bracket on the top of the fan, on the attic side, after the fan is ...
Sort of Damocles's user avatar
6 votes
Accepted

Can I place ventilation ducting on top of joists if there is space?

I'm confused/surprised by the existence of the void, but if you've got the space, then go for it. The only bit of mathematics to be concerned with is matching the cross section of the various ...
Aloysius Defenestrate's user avatar
6 votes
Accepted

Bathroom exhaust vent into crawlspace

No, at least not under the international residential code (IRC): M1501.1 Outdoor Discharge The air removed by every mechanical exhaust system shall be discharged to the outdoors in accordance with ...
Robert Nubel's user avatar
6 votes

How to wire 3 separate switches to a single exhaust fan

The answer to your question depends on many exact details of your existing circumstances. Are you building anew, or are you modifying an existing construction? If modifying, do you have access to run ...
A. I. Breveleri's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible