Thanks for the reply, @HU-867564120. To be clear, you are saying the mirror and upper wall condensation should NOT be happening with an effective fan? That's really what I'm trying to know because I've been told that my expectation isn't realistic. My fan is supposed to be effective for a room three times the size of mine so I'm not sure if a fan with humidity sensor will be any more effective. I was considering a Panasonic with humidity sensor. Showers aren't overly steamy (nor long), the room is rectangular with the fan above the alcove shower at one end. I'll take note of the humidity in the room and see about the ducting. Those are the only two elements I'm not sure about with current installation. Thanks again.

Re: "are saying the mirror and upper wall condensation should NOT be happening with an effective fan?" - How do you get that out of what I said?

I am confused by what you said and asking for clarification. "Sometimes things are rather obvious, and IMO, you already have your answer." Apologies but nothing is obvious to me about my situation. :)

Hi ,Your fan can't move out more air than is available. If your fan can move 120cfm and with the door closed it only lets in 10cfm via the space between the door and floor then the fan can only move 10cfm. You have to find a way to get more air in. I have installed louvered panels in doors to cure the problem.

Good Luck Woodbutcher

Open the window or take a cooler shower.

I can only offer my personal experience.

I have a Panasonic Whisper Fan which turns on and off based on ambient humidity level.

I have no condensation on my mirror and any condensation on the shower glass is gone almost immediately. I have no condensation on the walls of the shower or any other portion of the bathroom.

What is it like in the bathroom when you exit the shower? Is the atmosphere steamy. I can't imagine generating that much condensation even from a 15 minute shower. I don't time my showers but I am not in and out in 2 minutes generally.

Glad to know of your experience with the Panasonic Whisper Fan, @Helen. To answer your question, the atmosphere is not steamy when I step out of the shower. I don't think I'm using inordinately hot water when showering.

I would say there is probably an issue with the quality of your fan.

I am not an expert but I believe the Panasonic line of fans are rated really well. I know others besides myself have had excellent user experience with them.

The conditions you describe should not be happening - although even with my old mediocre fan - I didn't have condensation on the walls that lingered.

A new fan is a relatively small investment so you could try that as well as double checking with a HVAC person on terms of installation. My fan does not vent to the outside directly but into some mysterious cavern in my building :-).

I would say there is probably an issue with the quality of your fan.

Might be. I think I need to triple check the fan's installation first. Output on roof might be blocked. The fan is certainly not pulling the air it should.