Is there a dimmer light switch with secondary constant 120V output?

Question

I have a vent fan and an overhead light in my bathroom. They are currently tied to one standard light switch. When that light switch is in the "on" position, the vent fan and light are both powered on.

I want to replace the existing standard switch with a dimmer, but do not have space to add an additional switch in the room for the vent fan. The vent fan needs a full 120V to operate properly. I also want to ensure that the vent fan is running if someone ever has the light on in this bathroom no matter the dimmer setting, so adding a second switch doesn't help solve that problem even if I did have the space.

Is there a dimmer light switch sold that has both the variable voltage output (for the light) and a constant 120V output when the switch is on? I've searched the internet and called Lutron but haven't found anything.

If not, can you think of another way to solve this problem?

Thanks!

Answer 1

Check out lutron SFSQ-LF-GR 120v 360w 1.5 amp 3 speed fan control light switch on 1 yoke this will fit in your existing space since that was your concern. I may have mis read your question, so here is a light dimmer with a separate on off switch for the fan, Lutein MA-L3S25-WH. Hope one of those works. Or a pir sensor and switch so the fan turns on when you enter and a light switch combo but those are really expensive.

Answer 2

You can do this by mildly abusing a 3-wire fluorescent dimmer

While incandescent lights are happy with only a dimmed-hot and a neutral, some lighting systems (such as fluorescents) are tougher to dim using standard two-wire dimming. As a result, dimmable fluorescent setups use different ballasts that accept multiple inputs: one switched-hot to provide constant power for filaments and controls, and something else that controls the brightness of the light. The simplest "something else" you can use is a dimmed hot, and as a result, you get what are called "3-wire" dimmers and fluorescent ballasts, using a switched-hot, a dimmed-hot, and a neutral between dimmer and ballast.

In your case, while this isn't an officially sanctioned way of installing such a thing, a 3-wire dimmer is simple as all the switched-hot is is a tap after the internal switch, but before the dimmer electronics. As a result, you can put a 3-wire fluorescent dimmer in (Lutron makes them in most of the styles they make), then use the switched hot to control the vent fan and the dimmed hot to control the lights. Of course, you need to have a 3-wire cable running up to the fixture to do this; furthermore, these dimmers require a neutral, so if it's on a switch loop, you'll need to use /4 cable in order to provide neutral to the dimmer.