An air to air heat pump is a mechanical device that moves heat from an evaporator to a condenser in either residential or commercial applications. This system can be reversed by the use of a reversing valve which allows for a space to either be heated or cooled.
Heat pumps are efficient distributors of heat and utilize electrical energy very well. The cost efficiency is present because the device is not responsible for the creation of the heat, but simply for its transference from one place to another.
Types of Heat Pumps
Ductless heat pump systems are the least labor intensive as they only require a hole in the wall to connect the outdoor condenser and the indoor mechanicals. They are most useful in the construction of additions to a home.
A heat pump system requiring duct work uses already established duct work or will require its own configuration for effectiveness. Heat pump types are also divided into split, packaged, multi-zone, and single-zone.
Heat Pump Action
A heat pump involves the workings of a compressor and two coils usually made of copper. These coils are enveloped in aluminum fins that assist the transfer of heat. If the device is involved in the transfer of heat, then refrigerant contained in the outside coils extracts heat from the atmosphere turning it into a gas. As it condenses back into a liquid, the indoor coil will extract the heat from it.
Heat Pump Issues
Although they are efficient devices to either transfer hot or cold air, air to air heat pumps do have issues that have become noticed. Airflow may be impeded if there is low pressure or if the ducts are leaking. If there is an incorrect refrigerant charge, then performance will dwindle. Heat pumps that are sealed during manufacturing will be charged correctly. Split system heat pumps are charged by technicians who may miscalculate loads or refrigerant requirements. In addition, new research by the manufacturer of the pump may reveal other factors influencing the efficiency of the pump.
In the area of HVAC, an air to air heat pump is a vapor compression refrigeration device that involves a reversing valve and heat exchangers. Thermal energy may be reversed in this type system. Seasonal Energy Efficiency Rating(SEER) for energy star products must be at least 14.5SEER.
All mechanical devices create noise. An air source heat pump will require an outdoor unit that has moving parts. The outdoor unit will also have a fan and a fan motor that constantly turn on and off as the thermostat calls for heat or cold. These will all increase the decibel levels coming from their actions. In addition, if the cycle is reversed there may be a sudden change in the sounds coming from the fan. This can be significant in very quiet areas.
Heat Pump Varieties
There are a variety of air to air heat pumps. A ground source heat pump extracts heat from the ground. There are four varieties of this kind of heat pump. They include ground, soil, rock, and water.
Exhaust Air: This type of heat pump extracts heat from the exhaust air of a building or home.
Water Source: This device uses water as a source for heat. There are single pass and recirculation cycles.
Hybrid: In this type, when the air is between 40-50F air is used. When the air is colder, the ground temperatures are used.
Air/Water-brine/water heat pump (Hybrid): This hybrid only uses renewable energy sources.
Solar Assisted: This pump combines the action of the pump with the energy supplied by solar panels.
In other research, inventors have created heat pumps that use magnetic, thermoelectric, and thermo acoustic energies to move heat.