Any heat source that heats air will change RH levels it is just the way it is. Radiant sources don't as much but they also don't heat the air much either.

I work in a small university some profs want the students to 'sir' them (or doctor...) I don't. With out getting too into it trying to force student to respect you is ridicules. My students respect me and I respect them we learn together. Sir in MY mind represents the opposed methods. It often spills out, sword and shield are standard responses for me it is almost automatic. I did not intend to suggest anything by it. It is my issue, not yours, I should not have mentioned it. I am sorry for that.

Back to the issue I would suggest a alternative, remember heat rises and humid air rises we sometimes forget basic physics 'round here.

http://ball-pythons.net/forums/showt...arium-Solution

This shift solves much of the issues heat and humidity do not escape out the top WITHOUT sacrificing ventilation the high low vents allow air in and out very efficiently. The lights mounted inside (fluorescent lights or FL) hold ambient temps but do not become hot enough to pose a threat. They typically will not under any conditions heat over 85-6º ambient although this is the upper limits of ambient air temps it is not easy to get there under normal room temps (68-73º) A simple timer can control the temps as it really is only ambient heating and this has a huge range (75-88) I always avoid the ends but 77-85 is a safe level. Not too hard to hit with just timers. I change my timers every 3 months or so. The UTH does the hot spot and that is T-stat regulated. Simple and efficient and not too expensive.

Many are intimidated by working plastics but I only used a bit of fine sandpaper matt knife and ruler with a drill and new bit. Nothing major it took me two TV shows (1.5 hours) to complete on the living room table. It might be worth investigating.