5 Five Applications of Heat Pumps

5 Five Applications of Heat Pumps: A heat pump works by using the refrigeration cycle to move thermal energy from outside to provide heat to the building. It can also work in the opposite direction by extracting heat from an enclosed space and releasing it outside to cool the area. Air conditioners are a type of units that only provide cooling. In heating mode, the refrigerant is compressed at the outside temperature, causing it to heat up and transfer thermal energy to the indoor unit. When the refrigerant is returned to the outside, it condenses and evaporates, resulting in a loss of thermal energy and becoming cooler than the surrounding environment. The refrigerant can absorb energy from the air or ground before the process starts again. Electrical energy is required to operate compressors, fans, and pumps.

Air source heat pumps are the most common model, although there are other variations, such as ground source heat pumps, water source heat pumps, and exhaust air heat pumps. In district heating systems, heat pumps are also widely used. The efficiency of a heat pump is measured by its coefficient of performance or the seasonal coefficient of performance, with higher numbers indicating greater efficiency and lower energy consumption. In the case of space heating, heat pumps are generally more energy efficient than basic electric resistance heaters.

Important Types of Heat Pumps

Geothermal heat pumps work by using a heat exchange fluid (usually water mixed with antifreeze) to extract heat from the ground or groundwater. The installation cost of geothermal heat pumps can be high. It can also be employed to create a cooler structure by transporting heat from hot areas and channeling it into the ground through piping located underground. A water source heat pump works similarly to a geothermal heat pump. However, it derives its heat from bodies of water rather than land. The essential criterion is that the body of water should be substantial enough to withstand the cooling effect of the unit and should not cause any negative effects.

The basic function of an air source heat pump is to transfer heat between two heat exchangers. Usually, one of the heat exchangers is located outside the building and comes with a fan to force the air using a fan. A second heat exchanger is used to heat the air or water directly inside the building. This heated air or water is then circulated through heat emitters, which release heat around the building. An exhaust air heat pump is used to remove heat from the exhaust air of a building. However, they require mechanical ventilation. Two types of exhaust air heat pumps are available. The first is used to transfer heat to the air, while the heat of the second transferred to the heating circuit, including the domestic hot water tank.

A solar-assisted heat pump combines two systems, a heat pump and a thermal solar panel, into one integrated system. The solar thermal panel acts as a low-temperature heat source, while the heat generated is supplied to the evaporator of the heat pump. Absorption heat pumps, also known as gas-fired heat pumps, are a recently developed type of heat pump used primarily in residential systems. They rely on heat as their main energy source and can be combined with a variety of heat sources.

5 Important Applications of Heat Pumps

Heat pumps are typically used in areas with moderate demand for heating, ventilation, and air conditioning (HVAC) services; They can also serve as a source of domestic hot water and a means of drying clothes. Let us now examine the important uses of heat pumps.

Space heating and cooling

Centralized heating systems use a single unit to generate heat that is then distributed throughout the home. These systems can use a variety of fuel sources, including oil, electricity, liquefied petroleum gas, and natural gas. Electric heating systems are considered a safer and healthier option as they do not produce any harmful by-products. Despite its advantages, electricity can be more expensive than propane and oil. Additionally, electric HVAC systems can stop working during a power outage.

While oil and propane heating systems are efficient at converting fuel to heat, they require homeowners to have large storage tanks to hold the liquid fuel. On the other hand, natural gas heating systems can achieve fuel-to-heat conversion efficiencies of up to 99%, but they require a properly functioning ventilation system to release carbon monoxide gas. Propane, oil and gas systems are generally less expensive than electric but are not as environmentally friendly. It is important to note that the prices of these fuel sources can be extremely volatile, which can make it challenging for homeowners to estimate their heating costs.

District heat

In 2021, district heating production increased by about 3% compared to 2020 and was able to meet about 8% of global final heat needs in both industrial and residential buildings. District heating networks have the potential to efficiently, economically and flexibly incorporate low carbon energy sources into the large-scale heating energy mix. District heat production is mainly concentrated in China, Russia and Europe, accounting for more than 90% of global district heat production. Despite this, the decarbonization potential of district heating remains largely unexplored, as most district networks supply globally (about 90% of total heat production), especially to the two main markets of China and Russia. Also dependent on fossil fuels.

Under the net zero scenario, district heating would continue to contribute a comparable proportion to global final heat consumption. However, progress in energy efficiency in district heating networks and building structures will enable a reduction of district heat supply by around 20% by 2030 compared to 2021. In this period, renewable energy sources (including renewable electricity) account for about 20% of district heat supply by 2030.

Industrial heat

The use of industrial heat pumps offers significant potential to reduce energy consumption and associated greenhouse gas emissions in industry. A global collaborative project completed in 2015 brought together a total of 39 examples of research and development initiatives and 115 case studies from around the world. Study results show that high reductions in CO2 emissions (in some cases over 50%) can be achieved with a short payback period of less than two years. Industrial heat pumps have the ability to provide heat up to 200 °C, which can meet the heat demands of many light industries. In Europe alone, around 3,000 facilities in the paper, food, and chemical industries could deploy 15 GW of heat pump installations.