How hot is your roof heater ???

I tried my Carrier electric roof heater twice now and I am very dissatisfied with its ability to heat the trailer. I can feel the air coming out is very...just slightly warm-ish.

I removed the plastic grille and verified that the passages are clear and I cleaned the heater coil and ran it without the grille installed. The air blows real strong and I can reach in (near the sticker that says "do not operate unit with grille removed ") and I can touch the heater coil and it is indeed hot however it is not glowing red hot.

Does anyone have any experience with this?