It may be just me, but I'd also rethink putting lights inside the greenhouse itself. I don't trust high humidity and light fixtures together. They don't play well.
I was thinking about that too... don't want the bulb to pop...
That's why I've got my lights all out of any possible chances of humidity buildup areas.
Lights are in and of themselves humidity buildup areas. They have hoods, complex curves, nooks and crannies. Granted, their heat usually keeps the humidity at bay, just something to think about.
?? Its always beeen my experience that the lights dry out the moisture around the fixtures and the bulbs, and the heat rises keeping the area above them dry also so no need to worry about dripping water from moisture building up.
ed
Not my experience. I've had T8 fixtures ruined by setting them inside high humidity setups. Believe me, this is from experience.
So what to do? Set light on top of a piece of plexiglass?
Could be Ryan, I have only used the T-5 tube type bulbs and the regular grow bulbs that screw into a normal light socket. My tube bulb is 5 years old and still lights up, I think it needs replaced though as it seems dimmer to me, and the little grow bulbs get broke all the time due to the clamp that gets loosened when bumped. I do not use any special humidity boosting thing but I do water it daily and there is moisture on all the walls, except near the lights.
ed
Thanks Ryan. Seemed like an easy and cheap answer for protecting equipment.