I've used a ZooMed 100W emitter with a fluker's 8.5 dome with built in dimmer in 20 gallon tank. Depending on season, the dimmer was turned 50% to 60%. Also, the screen top was blocked around 80% to help maintain humidity. If your dome does not have dimmer; heat emitter will require a rheostat dimmer (manual) or a thermostat (auto).

They have long long life due to their construction. Humidity drying effect is related to the heat; not the source of it. Think a 100W incandescent lamp will dry as much as a 100W ceramic heat emitter .