Heat Pumps
Electro-mechanical devices used to transfer heat from a point at lower temperature to another at higher temperature are known as heat pumps. The point from where excess heat is transferred is known as a source while the point where this heat is transferred to is known as sink. Heat pumps are widely used in extreme climatic conditions to keep the temperatures inside a building comfortable by drawing heat either from atmosphere or from under the ground.
A heat pump drawing air from atmosphere is known as an air source heat pump while the one drawing heat from under the ground is known as a geothermal heat pump. Depending on how it is used, and contrary to its name, a heat pump can be used for both heating and cooling.
The basic principle of operation of all heat pumps, including refrigerators, air conditioners and space heaters remains the same – transferring heat from a source at lower temperature to the sink at higher temperature while drawing little power.
Need of periodic Maintenance
Heat pumps are usually more energy efficient than alternative devices like air conditioners and electric furnaces. However, just like other appliances, they also need periodic maintenance and service.
A functional knowledge of basic components of a heat pump can prove to be handy in easy identification of heat pump problems. A heat pump essentially consists of a compressor, an evaporator – which is basically a circulating fan, valve to reverse the air flow, refrigeration unit also known as condenser.
Troubleshooting
Here are a few guidelines which would serve you well in fixing minor problems in your heat pump. Before you initiate heat pump troubleshooting, make sure that electricity supply to it is turned off.
1. If no heat is transferred, check the main power supply. In case it is fine, check whether the compressor motor is overloaded. If yes, pressing the reset button should start the motor. In case it doesn’t work, seek professional help.
2. If sufficient heat is not transferred, check for the obstructed air ducts. Other possible causes can be a lower setting of the thermostat or presence of dirt on air filters. Set the thermostat properly and clean the air filters for smooth operation.
3. Another reason for insufficient heat transfer is either low pressure refrigerant, compressor damage or an unclean evaporator. Likewise, high refrigerant pressure is usually caused due to excess of refrigerant and an unclean condenser. Check these systems regularly to make sure that heat pumps continue to work without trouble.
4. Heat pump freezing is another common problem caused either due to insufficient blower speed or clogging of evaporators or filters. To fix such problems, defrost your heat pump if possible. If such option is not available, seek help of HVAC professional.
5. If your heat pump makes strange sounds during daily operation, check air ducts and mechanical parts of the heat pump like belts, wheels and the like. Fix the causes as necessary and check if such sounds are done away with.
Some additional servicing guidelines to prevent heat pump problems include cleaning fan blades, air ducts and air filters regularly.
