Reddit mentions of ENERLITES Countdown Timer Switch for bathroom fans and household lights, 1-5-10-15-20-30 Min Settings with Manual Override, Always On Blue LED, Neutral Wire Required, UL Listed, HET06A-R, White

I've heard mixed reviews on the 'humidity sensor' activating switches. I'd rather go with a nice selectable timer switch, I use something like these:

https://www.amazon.com/dp/B00IB0ZJXE/

Funny you mention that, I am going to be replacing the regular switch for the fan with this variable timer one

This is the one that I have: https://www.amazon.com/Enerlites-HET06A-White-1-5-10-15-20-30-Countdown-Decorator/dp/B00IB0ZJXE/ref=sr_1_6?keywords=timer+switch&qid=1550149892&s=gateway&sr=8-6

It works great. The blue led's are fairly bright and would annoy me if my bathroom was attached to my bedroom.

I’ve always heard that if it can hold a square of toilet paper, then it’s working. It could be as simple as it’s not running for long enough, I leave mine off during my shower, but let it run for ~20 min after. You can get a simple timer switch and let it run after you get out.
Enerlites HET06A-White 1-5-10-15-20-30 Minutes Preset In-Wall Countdown Timer Switch, w Decorator Wall Plate, White

I thought about doing a sensor fan, but instead decided on a timer switch. It's $18, and I just hit the 30 minute timer when I start the water or turn on the bathroom light. Minimum disruption to existing routine, super simple, no clouds required!

https://www.amazon.com/Enerlites-1-5-10-15-20-30-Minutes-Countdown-Decorator/dp/B00IB0ZJXE/ref=zg_bs_6291360011_3?_encoding=UTF8&psc=1&refRID=JV49D0QGGTRQQFVVQ701

Yes, steam. I'm going to install a timer like this (https://www.amazon.com/dp/B00IB0ZJXE/ref=cm_sw_r_cp_apa_i_VbcuDbN1N82VX) so I can run it for 20 min after. I failed at calculating cubic feet, not so sure I could figure out how to calculate particle velocity :).

I put a pair of these in my house, they're great and pretty cheap.

keeping bathroom door closed and a fan timer helped us.
https://www.amazon.com/gp/product/B00IB0ZJXE/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I got this one. I thought the time selection was better.

Motion sensors are probably the best way to go, as others have said, but I'll offer a different alternative. This switch has a built-in timer that you can set for 1, 5, 10, 15, 20 or 30 minutes. There's also other timer switches out there, some of which can even be programmed.

dude this has been done lol like, a loooong time ago

https://www.amazon.com/Enerlites-HET06A-White-1-5-10-15-20-30-Countdown-Decorator/dp/B00IB0ZJXE/ref=sr_1_5?ie=UTF8&qid=1541461177&sr=8-5&keywords=countdown+timer+switch

These are pretty simple to install.

I also really like switches like these but they're a bit more involved to install.

I just make a habit out of checking them all the time, but these are pretty simple ways to make sure everything runs as little as possible.

Hi! If you're a big DIY person, I found these companies on Amazon called Top Greener and Enerlites where you can install your own light switches. The one that I have all around my house are motion sensor switches and the fan/light timer. So far, I've noticed my bill has gone down. I think it's good because when you program the lights, they basically turn off themselves. Anyway, I'll provide the links if you're interested so you can make a better decision.

https://www.amazon.com/Enerlites-Programmable-Lighting-Vacation-Daylight/dp/B00TSU5GB6

https://www.amazon.com/TOPGREENER-TSOS5-W-Single-Pole-Fluorescent-Incandescent/dp/B015G8VLNA

https://www.amazon.com/Enerlites-Countdown-Ventilation-1-5-10-15-20-30-REQUIRED/dp/B00IB0ZJXE

I used this for our bathroom fan. Max is 30 min.

Enerlites HET06A-White 1-5-10-15-20-30 Minutes Preset In-Wall Countdown Timer Switch, w Decorator Wall Plate, White https://www.amazon.com/dp/B00IB0ZJXE/ref=cm_sw_r_cp_taa_wucvDb16G0QPJ

Tire of the kids leaving the fan on all day and night. Didn't want to heat or A.C. the outside all the time. Went in quite easily.