Heat pump

Central heat pump system is designed to cool or heat a condition space by providing cooling in the summer and heating in the winter. The cooling is accomplished by metering liquid refrigerant with the use of a metering device to control the amount of liquid refrigerant entering the evaporator. This liquid then evaporates by absorbing heat from the condition space by the use of a fan motor. The refrigerant at this stage turns to low pressure gas, which then travels back to the compressor to be compressed and starts the process all over. The heating process occurs in the opposite way by the use of a four way reversing valve. This valve changes the flow of the refrigerant so that the system is now conditioning the outside or pulling heat from the outside (due to the refrigerant being colder than the outside temperature) and dumping it inside the space.

Heat Pump working principle.

A typical heat pump system consists of two main components, an Condensing unit otherwise called an outdoor unit and an Evaporator Coil otherwise known as an indoor air handler unit. Both of these units contain various important components.

Outdoor Unit

The most important components in an outdoor unit are: A circuit board, compressor, reversing valve, expansion valve, condenser coil, refrigerant and a fan motor. All these items are what makes the heat pump system operates in cooling or heating mode.

Condenser Coil and Fan Motor. 

The condenser coil operates as a heat exchanger regardless of the weather or season. However, in the cooling mode, the coil would release the heat absorbs by the refrigerant from the condition space. whereby, in the heating mode the coil would absorbs the heat from the outdoor environment. The fan motor would pull outdoor air across the coil to facilitate the heat exchanging.

Evaporator Coil or Indoor Unit

The indoor unit, commonly referred to as the Evaporator, contains a coil and a fan motor. The coil also acts as a heat exchanger during the heating and the cooling season.  Therefore, in cooling mode, the refrigerant that flows through the evaporator would absorbs the heat out of the condition space. However, in the heating mode, the refrigerant inside the evaporator would release it’s heat into the condition space. The fan is responsible for moving air across the Evaporator coil and throughout the condition space. 


The refrigerant is the substance that absorbs and rejects heat as it circulates throughout the heat pump system.


The compressor is the heart of the heat pump system. It is responsible to compresses the refrigerant from low to high pressure gas. Therefore, it’s job is to pressurizes the refrigerant and moves it throughout the system.

Reversing Valve or Four Way Valve

This electronic control valve is responsible for reversing the flow of refrigerant during the heating or cooling process. It is control by the circuit board and will turning on and off during a defrosting cycle.

Expansion Valve

The expansion valve acts as a metering device, regulating the flow of the refrigerant as it passes through the system, allowing for a reduction of pressure and temperature of the refrigerant.

heat-pump installation, repair and service.

How does a Heat Pump Work?

A heat pump operates by transferring heat energy from the outside atmosphere and delivers it to the condition space. This action takes place by a source of heat to what is called a heat sink.  Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer, by absorbing heat from a cold space and releasing it to a warmer one. When discussing heat pump efficiencies, the following terms are commonly used: coefficient of performance (COP), seasonal coefficient of performance (SCOP) and seasonal performance factor (SPF). The more efficient a heat pump is, the less energy it consumes and the more cost-effective it is to operate. There are several factors that will affect the efficiency of a system such as heat pump service, repair, install, climate, temperature, auxiliary equipment, technology, size and control system. 

heat pump

When should a Heat Pump Service, Repair and Install?

Heat Pump Service – it is recommended by the manufacturer to have your system inspect and service once per year.

Heat Pump Repair – repair should be done by a certified individual or contractor. 

Heat Pump Install –  install must be done properly for the unit to perform at the highest efficiency. 

How Does A Heat Pump System Works In Heating Mode?.

Heat pump in heating mode operates just like cooling mode, except that the flow of refrigerant is reversed. The evaporator become the condenser and the condenser become the evaporator. What this means, hot air will be coming out of the evaporator while cold air coming from the condenser. The science behind this process, is to place the cold refrigerant in the condition space for heat absorption. In other words, heat is absorbed in the outdoor unit by cold liquid refrigerant flowing through the condenser coil.

The heat absorb by the cold refrigerant gas enters the compressor to be compress turning it to high pressure, high temperature gas. The hot gas changes state in the evaporator by giving up it’s heat due to cold air passing over the coil. The warm liquid travels back to the outdoor unit, which gets meter into the condenser coil for another cycle.

How Does A Heat Pump System Works In Cooling Mode?.

When the system is in the cooling mode operates in the same principle as an air conditioner. During this process, the evaporator will absorb heat from the condition space and replacing it with colder temperature. This heat absorb by the refrigerant will be taking to outdoor unit and release through the process of condensation. 

Heat Pump Repair and Service.

A heat pump system won’t last forever and will need to be repair or service at some point. Therefore, customer should be prepare to have their system repair or service whenever needed. With our team of experts, we have many years of experience in a wide range of heat pump. However, manufacturer recommend you should service or maintain your heat pump system yearly. Therefore, by doing so it will extend the life of your equipment.

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