In my experience it's easier and far more practical to heat the over-all enclosure at least to the cold side temp. And only use the supplemental heat for hot spots.

Also it's my experience that oil filled radiant heaters do not dry out the air. That is a symptom of forced air heaters. For humidity issues I recommend increased misting cycles or changing out a substrate that holds more water, without turning to mud.

Cheers
-----
Jeremy Payne
JB Reptile

1.0 Snow "Kahl"
0.2 Triple Het Moonglow "Kahl"
0.1 Orange Tail Hypo Het Leopard
1.0 Ghost
0.1 DH Ghost
1.1 "Kahl" Albino
1.0.2 Hypomelenistic
1.3 Pastel Hypo
0.1 Anerthrystic
0.0.1 Normal

0.1.2 Morelia Viridis