A heat transfer apparatus includes one heat exchanging system having a compressor coupled between a condenser and a heat exchanger. A further heat exchanging system includes a water pump, an ion exchange filter coupled between the water pump and the heat exchanger, to filter negative ions, positive ions, mineral materials, and/or impurities from the water. A temperature detecting member may actuate a heater to maintain the water temperature. A water cycling system includes a water reservoir to maintain the water pressure in the further heat exchanging system. An air relief valve may relieve air bubbles to reduce shocks and vibrations in the heat exchanging system.