Regarding dehumidifiers & heat:
A dehumidifier is, in some ways, a "broken" air conditioner in that both the condensation and evaporation coils are in the same unit. The room air flows past the evaporation coils first, which are operating at about 42 deg F, the room air is either lowered to its dewpoint or down to about 52 deg F, water condenses and is drained away, then this same air blows past the condenser, which is typically operating at about 110 - 120 deg F.
The net result coming out of the unit is considerably less water in the air at a higher temperature in the room.
Since the maximum efficiency of any compressed gas heat engine is about 50% (see Carnot Cycle on Wikipedia if you want the thermodynamic explanation), and a real-world heat engine is considerably less efficient than the theoretical efficiency, you can expect that about 30% of the electricity is converted to condensed water, and about 70% is converted to heat.
In other words, you can actual calculate how much heat will be added to your room while the dehumidifier is running by multiplying its energy consumption by 70%. For example, this dehumidifier:
http://www.amazon.com/dp/B00AU7GZXE
Uses 745 watts while in operation. About 520 watts of that is exhausted back to the room (that's about what a hair dryer puts out on the "low" setting).
So obviously, if you want to dehumidify
and cool the room, you're better off with an air conditioner that will vent the heat to the outside.