Everything You Need to Know About Electric Inverter Heat Pumps

Living in a place with extreme weather conditions can be challenging, but heat pumps can make homes and workplaces comfortable. They extract heat from the atmosphere and deliver it to various building components, or they can work the other way around. The latest innovation in temperature control is inverter-based heat pumps. They can enhance comfort by maintaining temperature with ±0.5°C accuracy. In contrast, traditional heat pump designs work on the principle of turning ON/OFF, causing large fluctuations in temperature that can be discomforting for many.

If you plan to purchase heating or cooling equipment for various applications in your building, choose inverter heat pumps. They provide substantial energy savings compared to all other temperature control equipment. Electric inverter heat pumps offer an extra 20% heating capacity using the latest brushless DC fan motor. To learn more about the technology, continue reading the blog!

What is a Heat Pump?

To fully understand an electric inverter heat pump, we need to develop an understanding of the basics of heat pump operation. The principle operation and circuit are the same as those of traditional heat pumps. However, introducing DC (direct current) to the refrigerant compressor has drastically improved efficiency. We will discuss DC and inverter technology in later sections.

How Does a Heat Pump Work?

A heat pump consists of a circuit containing a compressor, expansion valve, drier, and indoor/outdoor units. Tubes connect all these components and consist of a refrigerant, which can be R-32, R134a, or R410a. Here is how these components work in heating mode:

  1. The compressor compresses the refrigerant, increasing its temperature. It also pushes the refrigerant inside the tubes to start moving it inside the circuit.
  2. The heated refrigerant moves to the indoor unit, releasing heat to the room, pool, floor, or domestic water. After releasing heat, the refrigerant temperature decreases.
  3. Now, the slightly cool refrigerant passes through the expansion valve, which causes an effect opposite of compression. The refrigerant temperature drops drastically, becoming lower than the temperature outside the building.
  4. The atmosphere is at a higher temperature than the refrigerant, which causes the temperature to increase.
  5. Warmer refrigerant then goes back into the compressor to repeat the cycle.

Heat pumps have multiple expansion valves and a reversing valve that causes the circuit to operate in the opposite direction during cooling. Heat pumps' diverse applications make them ideal for areas with extreme weather conditions.

Air Conditioner Vs. Heat Pump

At its core, a heat pump is similar to an air conditioning device but has some added features and components. Unlike air conditioners, a heat pump can provide heating and cooling by adding two non-return valves, an expansion valve, and a reversing valve. The remaining elements are similar to an air conditioner.

What is an Electric Inverter Heat Pump Technology?

The electric inverter heat pump is a device that extracts heat from the atmosphere and delivers it to the indoors for heating applications. It can also work the other way around, taking heat from the indoors and rejecting it to the outside atmosphere. This means it can switch between cooling and heating at user demand.

Single Stage Vs. Inverter Heat Pumps

In traditional heat pumps, the compressor that moves the refrigerant inside the heat pump works at a fixed speed. When there is no heating demand, the compressor stops and waits for the temperature to drop significantly before starting again.

In comparison, the compressor of inverter heat pump technology can vary speed based on temperature conditions. The compressor operates using a motor, and changing the motor speed requires variable-frequency technology. Inverter heat pumps can vary the frequencies of all the associated fans and compressors in the system. Their ability to adjust their speed instead of turning on and off improves their efficiency.

Compressor Regulation and DC Inverter Technology

We must dive deeper into the components to further explore compressor regulation and inverter technology. Here is an example of how the DC inverter technology works:

  • Conversion to DC Current: The voltage in our wall sockets is AC (alternating current). In AC, electrons move forward and backward almost 60 times in a second in the USA. However, this number can vary depending on the country. The electric inverter heat pump will have a bridge rectifier to convert it into DC for the compressor. It is like a one-way road that does not allow current to flow in the other direction. When electrons move in one direction, then electricity is DC.
  • Voltage Boost: We need to boost the DC to a higher voltage. The electricity should have decent power to cause the compressor to speed up and slow down efficiently. The voltage boosting occurs by utilizing capacitors.
  • Insulated-Gate Bipolar Transistors (IGBTs): A switch turns on and off rapidly, thus controlling the current that passes through. The speed of the compressor's work is regulated using the IGBTs. With a DC motor, the compressor can operate more efficiently than an AC motor.

Using a DC compressor and brushless DC fan to pass air through the outer unit increases the efficiency of the whole heat pump.

Ultra-Comfortable Temperature Regulation with Electric Inverter Heat Pumps

As a user, you will set the temperature you want to achieve in your room, swimming pool, tap water, or floor. The electric inverter heat pump starts at its lowest speed. It takes feedback, considers user requirements, and keeps increasing the speed until it reaches the desired temperatures. The compressor will maintain its speed if the indoor unit temperature matches the set point.

Operating in this manner is highly efficient and comfortable. Traditional heat pumps had huge temperature variations as the compressor worked at 100% or 0% capacity. In comparison, the inverter compressor varies speed to keep the temperature near the setpoint, reducing temperature fluctuations.

Heat Pump’s Dual Functionality

One of the most significant advantages of a heat pump is its ability to provide cooling or heating. Its year-round usability makes it the ideal system for providing a comfortable home environment. The heat pump contains a reversing valve. Depending on the heat or cooling mode, the compressed refrigerant can be sent to the inner or outer unit. It provides the best efficiency against any other electric heating method in both cases.

Pros and Cons of Electric Inverter Heat Pumps

Electric inverter heat pumps have more advantages than disadvantages than traditional non-inverter heat pumps. Their ability to adjust the temperature slowly and gradually leads to many benefits.

Advantages of Inverter Heat Pumps

  • Savings: Owing to the DC compressor and brushless fan motor, the varying frequency leads to 20-30% savings on energy bills.
  • Noise: The noise levels of inner and outer units are significantly lower owing to the soft startup and speed variation.
  • Environmental Friendly: Reducing energy consumption leads to lower carbon emissions caused by creating electricity to power heat pumps.
  • Stable Temperature Control: Electric inverter heat pumps can vary fan and compressor speed to provide stable temperature control that deviates slightly from the user's setpoint.
  • Homogeneity in Temperature: Longer run times allow temperatures throughout the space to become constant. So, depending on the indoor coil location, there is not too much heat in one place and too cold in another.

Disadvantages

  • Initial Cost: Inverter heat pumps have a higher initial cost due to the more significant number of instruments and components required for their operation.
  • Maintenance and Installation: The installation and maintenance costs are high as replacement parts are expensive.

How to Choose and Apply Electric Inverter Heat Pumps

If you plan to purchase an electric inverter heat pump for your home or workplace, consider several factors explained in our guidelines.

Key Factors to Consider

Factor 1: Type of Heat Pump

There are different types of heat pumps depending on the application. Heat pumps can maintain the temperature of air, water, or the floor. Some high-capacity heat pumps can simultaneously maintain the temperature of domestic water, pool, and space. However, their initial cost is higher and expensive to maintain.

Factor 2: Heat or Sink Source Selection

The refrigerant in the heat pump loop rejects or absorbs heat from the outside. It can gain or release heat to the outside air, water source, or ground. Depending on their surroundings and local regulations, users can decide on any one of the three methods to reject or gain heat:

  • Air Source
  • Water Source Heat Pump (Open or Close)
  • Ground Source (Vertical or Horizontal)

Factor 3: Energy Efficiency

Rising energy bills are a cause for concern for everyone. A standard method to check a heat pump's efficiency should be established: SEER2, EER2, and HSPF2.

  • EER2: The Energy Efficiency Ratio is calculated by dividing cooling output in BTUs per hour by electrical power input in watts. It gives an idea of heat pump efficiency at peak cooling load, which means when the outside temperature is hot.
  • SEER2: The Seasonal Energy Efficiency Ratio provides the heat pump's overall efficiency throughout different seasons. A higher SEER2 means that the heat pump will be efficient throughout varying seasonal temperatures.
  • HSPF2: The Heating Seasonal Performance Factor is the ratio between total heating output in BTUs and total energy consumed in watt-hours. It represents the efficiency of a heat pump in terms of heating requirements. Higher HSPF means better heating performance.

Factor 4: Refrigerant Type

Refrigerant quality depends on their freezing point and GWP (Global Warming Potential). Two refrigerants are mainly available in wide-scale applications: R32 and R410A. R32 is more efficient than R410A due to its higher operating pressure and low GWP.

Factor 5: Equipment Capacity

A general formula that users can utilize to find out their space heating requirements is:

Square feet multiplied by average ceiling height x desired temperature x 135 = BTU per hour

However, this is just an oversimplified method of calculating the equipment capacity requirements. It is better to get an HVAC expert to perform the calculations based on your extreme weather conditions. They can also include space and water heating in the calculations for a better and more accurate result.

Factor 6: Application

Are you planning to heat up or cool down your indoor air? Or do you need floor heating, domestic water, a swimming pool, or other heating or cooling requirements? You will need to explicitly know how much environmental conditioning you require in your building. You may need to hire an HVAC professional to calculate and size your system accurately for businesses.

The installation environment drastically affects the selection of a heat pump. The capacity, components, and power consumption are all vital factors when designing an HVAC system with a heat pump.

Local Law and Regulatory Consideration

The Department of Energy (DOE) in the USA and the European Union (EU) look after regulations that surround the efficiency of air conditioning. According to the Energy Policy and Conservation Act of 1975, DOE ensures compliance with energy and water preservation standards. Here are some snippets from the DOE's latest 2023 regulations:

  • Air conditioners installed in the North: 13.4 SEER2 (14 SEER)
  • Air conditioners installed in the South: 14.3 SEER2 (15 SEER)
  • Air conditioners installed in the Southwest: 14.3 SEER2 (15 SEER) & 11.7 EER2 (12.2 EER)
  • Heat pumps installed nationwide: 14.3 SEER2 (15 SEER) & 7.5 HSPF2 (8.8 HSPF)
  • Montreal Protocol, an international agreement, decided to phase out R-22-type refrigerants completely to protect the ozone layer and reduce global warming.
  • DOE is encouraging a shift to alternative refrigerants such as the R-410A, R-32, and natural refrigerants.

Maintenance and Care for Electric Inverter Heat Pumps

The longevity of your electric inverter heat pump depends on maintenance and care. It requires constant monitoring to maintain its maximum performance.

Regular Cleaning and Inspection

Here are some of the steps you can do at home to make sure that your inner and outdoor unit heat pumps operate efficiently:

  • Filter: Regularly clean the filter of your indoor unit. Dust can collect on the filter and restrict the flow of air, causing the fan or blower inside the unit to work at high speed without being able to move air.
  • Use a Blower: Some blowers blow air at high velocities that can instantly clean away all the dust inside the fins of your outer unit. Just be sure to turn the heat pump off before cleaning.
  • Condensate Drain: A pipe runs from your inner unit to the outside. Clean the condensate drain regularly, especially during summer, as it can get clogged and cause water to accumulate inside the unit, causing damage. You can use a blower to blow air across the drain pipe.
  • Energy Meter: Attach an energy meter to monitor the performance of your electric inverter heat pump to ensure that the power consumption has not increased or dropped drastically. In either case, it means an abnormality in the system.

Professional Maintenance and Routine Servicing

Opt for professional maintenance and routine servicing once a year. They will check the refrigerant pressure and condition of the coils, clean the electronics, monitor the compressor's health, lubricate moving parts, power wash coils, and test the thermostat. It will do wonders for your heat pump and ensure its longevity.

Conclusion: The Future of Electric Inverter Heat Pumps

There are constant improvements in the heat pump technology. The journey began with efficient refrigerant, AC-powered parts, and non-inverter technology. Now, highly efficient refrigerants such as R-32 and R410A reduce global warming and increase efficiency. DC fans and motors accurately control their speed through inverter technology to maintain a constant temperature.

The improvements have contributed to a better environment and sustainable solutions. Suppose you are looking for your subsequent space heating or cooling machine. In that case, we encourage an electric inverter heat pump with the latest refrigerant for high efficiency, environment-friendly, and low energy consumption.

FAQ

1.How does an inverter heat pump compare to a traditional heat pump in terms of energy efficiency?

Inverter heat pumps use variable-speed DC motors to control temperature accurately. Compared to traditional heat pumps, they provide a 20-30% improvement in efficiency, leading to lower energy bills and a better environment.

2.Can an electric inverter heat pump function in extremely cold climates?

Modern electric inverter heat pumps using R-32 refrigerant and DC inverter technology can provide heating at -12 °C atmospheric temperature and have a high-efficiency rating C.O.P of up to 16.

3.What is the average lifespan of an electric inverter heat pump?

A properly installed electric inverter heat pump with regular self-inspection and maintenance, topped with professional annual maintenance, can last as long as 15-20 years. That is because of lower thermal cycles on parts and higher quality of components.

4.How much maintenance is required for an inverter heat pump compared to a regular heat pump?

A regular heat pump may require more maintenance than an electric inverter heat pump as it experiences more significant current and temperature fluctuations. The on-and-off cycles cause thermal fatigue on parts in regular heat pumps, whereas the inverter changes temperature gradually.

5.Are there any government incentives for installing energy-efficient inverter heat pumps?

Governments can reduce taxes on energy-efficient inverter heat pumps to encourage their usage. They can also offer rebates and grants to ensure the technology is adopted. The Department of Energy (DOE) and the European Union (EU) also regulate inefficient systems.