How Do Inverter Heat Pumps Work?

Working principle of variable frequency heat pumps

Variable frequency heat pumps can achieve a comfortable temperature. The temperature of the variable frequency heat pump can be finely adjusted. Variable frequency heat pumps can also be used to save on expensive energy costs for homes or workplaces and keep them warm during cold winters. In the dry, humid, and hot months of summer, it can also keep the indoors cool. Variable frequency heat pumps come in ducted and ductless forms. Ducted ones are a cost-effective alternative to conventional air conditioning and gas systems. The operating capacity of ducted variable frequency heat pumps is 100%.

Ducted variable frequency heat pumps can operate at 100% capacity because they can run when the outdoor temperature is low. The heating system inside ducted variable frequency heat pumps operates in heating mode. Heating mode is cost-effective. Ducted variable frequency heat pumps are equipped with variable-speed compressors that can be used to control the system’s energy. Studies have shown that ducted variable frequency heat pumps can reduce energy consumption by 35%. They are equipped with compressor silencers to make the machine quieter after installing the compressor silencer.

Ductless variable frequency heat pumps are known for their mini-split system. The mini-split system in ductless variable frequency heat pumps is a system that allows customers to control the temperature of individual rooms or spaces. They have refrigerant lines. Ductless variable frequency heat pumps have an outdoor compressor and an indoor condenser. The indoor condenser is connected through refrigerant lines. These lines transmit the refrigerant. The refrigerant in ductless variable frequency heat pumps is the fluid used in the refrigeration cycle. It transfers between the units in the mini-split system.

How does a variable frequency heat pump work?

Variable frequency heat pumps have multiple operating modes. They use a variable-speed compressor (also known as a rotary compressor) that changes throughout the day. When using a variable frequency heat pump with a variable-speed compressor, it increases or decreases the speed. This is done to match the heat load inside the building. The compressor speed is influenced by changes in outdoor temperature.

In a variable frequency heat pump, they extract heat from the outdoor air. By doing this every day, the equipment can heat your building in winter. In summer, these heat pumps remove heat from the building. It can cool the air. By doing this every day, it reduces the energy consumed in the refrigerant cycle.

In the refrigerant cycle of a variable frequency heat pump, the cycle operates at different speeds. This depends on the temperature and heat load. During the cycle, the variable frequency heat pump adjusts the cycle speed. When there is a lower demand for heat load and temperature, the variable frequency heat pump reduces the output. This helps limit the energy consumption of the components. It helps reduce the number of start cycles required for the refrigerant.

The rotary compressor of a variable frequency air-source heat pump can operate within a range of 0-100%. The fan motor inside the heat pump can also operate within a range of 0-100%. 100% is the maximum value at which the rotary compressor and fan motor can run. The minimum operating speed of the rotary compressor and fan motor is 20%. However, this depends on the manufacturer and the type of components used in the variable frequency heat pump. Variable frequency heat pumps use direct current. The direct current power supply of variable frequency heat pumps uses a sine wave. A sine wave is a constant wave.

To use direct current, variable frequency heat pumps use a rectifier. A rectifier is a device that converts alternating current to direct current. After converting alternating current to direct current, the direct current is updated to variable frequency and voltage. Most variable frequency heat pumps are equipped with an Enhanced Vapor Injection (EVI) compressor. EVI stands for Enhanced Vapor Injection. Enhanced Vapor Injection expands the range of the heating cycle. It can operate at lower outdoor temperatures. Variable frequency heat pumps also use an Electronic Expansion Valve (EEV). EEV controls the flow of refrigerant into the evaporator. It achieves this by precisely controlling the movement of refrigerant flow. The electronic expansion valve is also known as a flow control device. It helps reduce the pressure of the fluid near the valve. In this way, it can vaporize the fluid.

After vaporization, the temperature of the refrigerant decreases. However, the electronic expansion valve may generate excessive movement of the refrigerant flow. When this happens, superheat is observed. To calculate the amount of superheat that occurs, the suction side temperature of the compressor in the reverse heat pump is subtracted from the evaporating temperature. The electronic expansion valve has temperature sensors installed on it. A second sensor is installed at the outlet of the evaporator. These two sensors calculate the superheat number.

The main components of the electronic expansion valve include a permanent magnet and a copper coil. They are located inside the stepper motor. The motor is located at the top of the electronic expansion valve. This is where the electromagnetic field is generated. The stepper motor is connected to the shaft. The shaft is connected to the thread. When the electromagnetic field is generated, the shaft pushes the thread. After pushing the thread, it advances the required thread into the valve seat. The valve seat is located inside the electronic expansion valve. The technology used in the electronic expansion valve comes from overseas countries like Europe.