Need help with a switch for a studio ventilation fan

[DFischer]

I have a modest size control room in my home studio that requires constant air exchange when in use. I'm currently switching the outlet feeding the fan with a standard timer designed for a bathroom fan. The timer's not really working out, because I often overstay the amount of time I programed in, or I'll forget to even turn on the fan in the first place. If I had to do it over, I'd wire the fan to the light switch, so that the fan would be on constantly when I was in there. Re-wiring at this point would be destructive and messy, so I thought about using a light sensor to turn on the fan in place of the time. Lights on = fan on. However, I can't seem to find any simple photocell sensors mountable in a switch box explicitly rated for fan use. There are plenty of motion sensors rated for fans, but not a lot of motion is happening while mixing.

Leviton gives these specs for motion sensor switches:



Am I right to think that the same ratios for resistive/inductive/capacitive loads would hold true for photocell switches? In other words, if I buy a photocell rated for 600W with a resistive tungsten load it would also handle a 1/2HP (372W) inductive motor load as well? Am I missing some other detail?

My current fan only draws 38W:
Fan

I'm looking at this switch replacement:
600W Switch

 

[DFischer]

I see the obvious flaw with original my question. Lights on and the fan goes off. I suppose I can use a relay to reverse states though. Any other suggestions?

 

[Newmarket]

The forgetting problem could be addressed by a post-it or noticed on the dask / chair / mixer etc

 

[DFischer]

The forgetting problem could be addressed by a post-it or noticed on the dask / chair / mixer etc

In a perfect world without me in it, then yes!

I actually found a marketing video from Intermatic where they show the mechanical relay they use inside their switch. It's an Omron G2RL-14-E, which should be able to handle my motor load. I just need to crack open the case and switch to relay to NC or re-wire the connections to the existing relay. That was nice of Intermatic to show the inside of their product.

 

[C.B. - Boudio]

Maybe connect the fan right at the power switch of your mixer?

 

[DFischer]

Unfortunately my control room is split in two zones with the wiring. The front is on a 20A circuit designed to run all audio devices. The back is on a separate 15A circuit on a different phase than the audio circuit for running the lights and fan.

The room is built with 2 layers of 5/8" drywall hung on RC channel on the inside, with 2 layers of 5/8" on the outside, all smeared with green glue. All the outlet boxes are covered in acoustic putty. I'll definitely live with the nuisance of the switch before I start cutting drywall or trying to fish wires through the rockwool.