Dehumidifier in a Fish Room

[MarkoD]

so i put a dehumidifier into my fish room and it does a great job lowering the humidity. but it puts out a lot of heat and was heating up the room and tank

so i decided to disconnect the bathroom style fan and vent the dehumidifier all the way outside. but still for some reason it seems to be heating the room a lot. (8 feet of the exhaust pipe is not insulated and probably releasing heat back into the room)

anyone have any suggestions?