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How Does a Heat Pump Work?

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The technical principles used by heat pumps are similar to the refrigerators or air conditioners. For instance, it mainly extracts heat from sources like the surrounding air, geothermal energy from the earth, nearby water, or even the waste heat from factories. Then, the heat is amplified and transferred to where it is needed. Since most of the heat is transferred rather than generated, heat pumps are significantly more efficient and cheaper than conventional heating technologies like boilers or electric heaters.


Efficiency and Performance

The heat pump produces an output of heat that is typically many times greater than the input of electrical energy required for operation. A typical domestic heat pump, for example, has a coefficient of performance (COP) of about four, indicating that it generates four times more energy than it uses. This makes modern heat pumps 3-5 times more energy-efficient than gas boilers. In order to increase efficiency and dependability, heat pumps can also be paired in hybrid setups with other heating systems, such as gas. This can optimize the overall energy efficiency of heat pump independently from outdoor temperatures.


Components and Functionality

A heat pump consists of two main components: a compressor and a heat exchanger. The compressor circulates refrigerant through a refrigeration cycle, while the heat exchanger removes heat from its source. The heat is subsequently transported to a heat sink through another heat exchanger.


In buildings, heat is delivered via forced air or hydronic systems like radiators or under-floor heating. Heat pumps can also be connected to a tank to produce sanitary hot water or add flexibility to the hydronic systems. Additionally, heat pumps can provide space cooling in the summer, making them versatile for year-round climate control.


Applications in Industry and Commercial Settings

Heat pumps are used in industry to supply hot air, water or steam, as well as to heat materials directly. Higher input temperatures are frequently needed for large-scale heat pumps used in commercial or industrial settings than for residential ones. These temperatures may originate from waste heat produced by wastewater treatment facilities, data centers, or industrial activities.

By utilizing renewable energy sources and lowering dependency on conventional heating techniques, heat pumps provide an all-around economical and energy-efficient option for heating and cooling requirements in both residential and commercial settings.


Heat pump Residential solution

R32 R290 heat pump Residential solution

Understanding How Heat Pumps Work: A Comprehensive Guide


Step 1: The Refrigeration Cycle Begins

In the first step of the cooling process, liquid refrigerant is pumped through an expansion device located in the indoor coil, which acts as the evaporator. As indoor air is blown across these coils, the refrigerant absorbs heat energy, causing it to evaporate into a gas. This process cools the air, which is then circulated throughout the home via the duct system.


Step 2: Compression of the Refrigerant

Next, the gaseous refrigerant moves to the compressor, where it is pressurized. This compression process significantly increases the refrigerant’s temperature, transforming it into the hot, pressurized gas. The hot gas then travels through the system to the outdoor coil.


Step 3: Heat Transfer and Condensation

At the outdoor unit, a fan blows outside air across the coils, which now function as condenser coils in cooling mode. Because the outside air is cooler than the hot refrigerant, heat transfers from the refrigerant to the air. During this heat exchange, the refrigerant cools down and condenses back into a liquid state. The warm liquid refrigerant is then pumped back to the indoor unit’s expansion valve.


Step 4: Pressure Reduction and Cooling

The expansion valve significantly reduces the pressure of the warm liquid refrigerant, causing it to cool down. Now in a cool, liquid state, the refrigerant is ready to be pumped back to the evaporator coil to begin the cycle again.


R290 air to water heat pump

R290 air to water heat pump


How a Heat Pump Works in Heating Mode

In heating mode, the heat pump operates similarly to cooling mode but with the refrigerant flow reversed by a reversing valve. This reversal means the outdoor air becomes the heat source, even at low temperatures, and heat energy is released inside the home. The outdoor coil now acts as the evaporator, and the indoor coil serves as the condenser.


The physics remain the same: the refrigerant absorbs heat energy outside, turns into gas, is compressed into hot gas, releases heat indoors, and then cycles back as cool liquid.


Heat Pump Installation: The Importance of Professional Expertise

Installing a heat pump is a complex task requiring specialized knowledge of HVAC systems and electrical connections. It’s crucial to have an expert handle the installation to ensure efficiency and safety. Local Shenling experts possess the necessary skills to assess specific heating and cooling requirements, properly size and position the heat pump, and consider factors such as ductwork and electrical compatibility. Trusting a professional ensures a properly functioning system and peace of mind.


Heat Pump Overview

Heat pumps are versatile, efficient systems that provide both cooling and heating. Thanks to a reversing valve, they can switch the flow of refrigerant to either heat or cool. The heat energy is transferred to the refrigerant through the blowing of air over an evaporator coil. The heat is then released by a fan at a condenser coil once this energy has been circulated there. Therefore, heat pumps are essentially devices that transfer heat.


For more information on ductless mini split and heat pump solutions, click here.


green the comfort

Frequently Asked Questions About Heat Pumps


Do Heat Pumps Use Much Electricity?

The annual energy consumption of heat pumps typically ranges from 6,176 to 10,244 kilowatt-hours (kWh), depending on factors such as unit size, efficiency rating (e.g., SEER and SCOP), and the specific heating and cooling needs of the house. Climate conditions also play a significant role. The extreme temperatures may require an increased operation of the heat pumps, leading to higher energy usage. Additionally, house insulation and overall energy efficiency affect the energy needs of heat pumps. Selecting a properly sized and rated heat pump tailored to the home’s conditions is essential for optimizing efficiency. 


Is a Heat Pump Expensive to Run?

Running costs for a heat pump vary, based on the local energy prices, system efficiency, and climate conditions. In moderate climates, heat pumps can be cost-effective compared to fuel-burning systems. However, in colder regions or areas with high electricity costs, heat pumps may require more energy to maintain comfortable temperatures, potentially increasing operating expenses. Factors like insulation, thermostat settings, and maintenance must be considered to assess the running costs for your situation accurately. 


What Are the Downsides to a Heat Pump?

A significant downside to heat pumps is their reduced efficiency in frigid temperatures, which can limit their effectiveness in harsh winter regions, potentially requiring supplemental heating. Additionally, heat pumps generally have higher upfront installation costs compared to traditional heating systems like furnaces.

For more details on how heat pumps work and other FAQ sections, feel free to contact Shenling.

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