Using a fogger to increase humidity?

Hi guys.
So I'm having humidity issues in my grow tent. It's running around 20% RH with the lights on and 60% with the lights off. Using 400w HPS and have an exhaust fan, but can't turn that off because it gets too hot in there.

I was wondering would a simple fogger for a reptile vivarium be a good idea to increase the humidity? You can get them for like eight pounds or so.

I don't see why not as long as there's a control gauge for the RH. No control could lead to it just spewing out fog all willy nilly and causing too much humidity and then condensation. I'd monitor closely for the first couple of days. You don't want condensation building up on your bulb and then the light flipping on.