Heat Pump inverter technology is a highly-efficient heating and cooling solution that keeps your home warm in winter and cool in summer. When compared to a conventional furnace or air conditioning unit, there is no comparison with an inverter.
Pictured above is an example of a current Trane heat pump. The XV20i Variable Speed heat pump has ComfortLink™ II communicating capability and unique refrigerant cooled inverter drive. See our Trane products guide for more on this and other units.
Heat pumps work by drawing heat energy from the air outside and use refrigerant to maintain a warmer temperature in winter. The cycle simply reverses in summer, expelling heat to keep the environment cool. The result is a significant decrease in energy loss during the refrigerant cycle.
Inverter Function
During a normal refrigerant cycle, the refrigerant continuously travels between the compressor and the condenser, turning from liquid into gas based on temperature. Once the air inside the home or building reaches the specified temperature on the thermostat, the refrigerant cycle shuts down completely and only restarts when the inside temperature changes.
Every time the cycle restarts, the system expends energy to balance the pressure and bring the refrigerant up or down to the proper temperature before the process of heating or cooling can begin.
Units that have a variable-speed inverter or compressor have a refrigerant cycle that operates at various speeds which are determined by heating load or temperature. The inverter eliminates energy losses caused by repeated starts and stops by adjusting the refrigerant speed automatically.
Heat Pump Inverter Benefits
Heat pump inverters reduce the amount of cycling to deliver a more comfortable, consistent temperature and to eliminate drafts. By minimizing the amount of energy lost during through cycling, they also improve energy efficiency in the home and reduce consumption (and the related cost) of energy. This not only allows you to keep your heating and cooling expenses under control, it is also favorable to the environment by reducing pollutants and emissions of greenhouse gases.
Some heat pump inverters also reduce noise during operation and most are capable of extending the life of both the compressor and other vital heating and cooling system components.
Another significant benefit related to energy efficiency is that, oftentimes, using an inverter will qualify for tax credits and both state and federal levels. Be sure that the unit you are interested in purchasing qualifies for these tax incentives. Be aware, also, that just because a unit is Energy Star-certified that does not mean that it automatically meets the requirements for tax credits. Do your research and make an informed purchase.
Cautionary Considerations
Heat pump manufacturers will often use “variable speed” and “multi-speed” interchangeably to describe heat pumps with inverter technology as well as the heat pump blower. Be careful when selecting an inverter based on this description. While a variable speed blower has benefits of its own, the pump and the blower are two different things.
Kinds of Heat Pump Inverters
Inverters come in both ducted and ductless varieties. A ducted unit works like any air conditioner or furnace, carrying air throughout the home through a configuration of ducts. Ductless units (also known as mini-split systems) have an outdoor compressor with an indoor condenser that are connected via tubes. The tubes transport refrigerant between the units which eliminates the need to have ducts.
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