An air handler apparatus includes at least one heat exchanger device with a cooling fluid region separated from a temperature transfer fluid region, an evaporator device comprising an evaporator housing and at least one evaporator coil, and a pump. The cooling fluid region has a cooling fluid input and a cooling fluid output and the temperature transfer fluid region has a temperature transfer fluid input and a temperature transfer fluid output. The evaporator housing defines an air passage having an air input and an air output. The evaporator coil has an evaporator coil input coupled to the temperature transfer fluid output and an evaporator output coupled to temperature transfer fluid input of the temperature transfer fluid region in the heat exchanger device. The pump is coupled to the temperature transfer fluid region in the heat exchanger device to pump temperature transfer fluid between the temperature transfer fluid region and the evaporator coil when activated.