Switch or occupany sensor based exhaust fan control

[katwalatapan]

Hello,

My application involves installing a light and exhaust fan in the washroom and switching the light and exhaust fan either via a manual switch or occupancy sensor. However switching sequence I am looking for is that the light could be turned on via a manual switch or an occupancy sensor, then I'd like at least 10 min delay to turn on the exhaust fan. The light switch could be turned off either via manual switch or occupancy sensor and the exhaust fan stays on for 20 minutes after the light is turned off and then turns off. I have reviewed products by leviton and lutron with timers and occupancy sensors, but could not find a product that could provide a delayed on and delayed off feature in the same product. Generally I find delayed off type products.

I wanted to inquire if someone may have any information on the type of product that I've described above.

Thank you.

 

[btrueblood]

Why a 10 minute delay on starting the exhaust fan? Depending on what the occupant ate, you may want it on right away.

 

[MiketheEngineer]

Why have delays??? You can buy these switxches at Lowe's or Home Depot!!

 

[ScottyUK]

There are plenty DIN-rail mounting timer relays which should be able to achieve what you are looking for. Google 'multifunction timer relay' - Omron, Finder, Crouzet, SAIA-Burgess, to name just a few manufacturers.

I do agree that a delayed on function is a little unusual.

 

[IRstuff]

Besides, 10 MINUTES?? That seems like a horrifically long time to put up with whatever that comes...

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[benta]

You can buy them off the shelf. I have an exhaust fan in my bathroom just as you describe.
Delayed turn-on and delayed turn-off (3 min. and 5 min., but this can probably be adjusted).

I would not recommend an occupancy sensor. They need movement to work, which means the occupant has to boogie on the seat while doing his/her business.

Benta.

 

[MiketheEngineer]

Do I even want to know what a "boogie" is??

 

[IRstuff]

It's done to the tune of "She's a Brick House"

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faq731-376

 

[jraef]

Here's what I posted in the other forum wherein you had asked this same question, just in case you didn't read it there...

I doubt you will find this as a finished "product" ready to go with that logic. You are looking at something that needs custom programming. A mfr like Leviton and Lutron would make a product like that if they could sell a million of them, but otherwise, it's too specialized.

It would be easy enough to create with a micro PLC or "Smart Relay", but someone would need to program it. How much is this worth to you though? Micro PLC / Smart Relay = $100, time to write (and test) the program, if you are ALREADY familiar with PLC programming, 1-2 days. If you don't know what a PLC is, figure a 1 week learning curve if you are reasonably intelligent and can figure things out. Barring that, you could build it with separate relays and timers in a control panel. More hardware cost and installation cost, less programming, but still involves being savvy with control logic. Depending on how you value your time, it seems like a lot of $$ to throw at a bathroom exhaust fan.

Why not just have the exhaust fan and light come on together and run on after they leave for a few minutes to clear the smell? The cost to turn the light off separately and leave the fan on will likely far outweigh the possible energy savings from turning it off for a few more minutes per day. I have a similar situation in one bathroom where I wanted the fan controlled separately only because of the noise, so I just put in a pull chain switch in the fan grill. Does the job.


"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
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[katwalatapan]

Thank you everyone for the response.