Views: 189 Author: Site Editor Publish Time: 2023-08-30 Origin: Site
Apart from the air conditioner vs heat pump debate, air source vs ground source heat pump is another comparison that always comes up every time there is a debate of the best heating, ventilation, and air conditioning (HVAC) system. This is because they are the two most popular and efficient heat pumps.
Choosing between them requires the consideration of many salient factors. Not only will you do a ground source heat pump vs air source heat pump based on popularity, cost, and efficiency. You also need to consider the practicality of the installation, lifespan, ambient temperature, environmental effect, application, rebate, space requirements, noise level, heat output, and renewable heat incentive (RHI).
Hence, in this post, we will give you a detailed difference between air source and ground source heat pumps to help you make an informed decision.
Air source heat pump (ASHP) is a heating and cooling system that absorbs heat from the outside air and transfers it indoors to provide warmth. Air source heat pump utilizes the energy in the ubiquitous air as the main power, and drives the compressor to run through a small amount of electricity to realize energy transfer. Air source heat pumps do not need complicated configurations, expensive water intake, recharge or soil heat exchanger systems and special machine rooms.
They can gradually reduce the emission of pollutants to the atmosphere caused by traditional heating, and ensure heating efficiency while taking into account the purpose of energy saving and environmental protection. It consists of two major types: air-to-water heat pump and air-to-air heat pump.
Air-to-Water Heat Pump: For this type, the heat absorbed from the outdoor air is transferred to a water-based system, such as underfloor heating or radiators. The air-to-water heat pump is ideal for central heating and hot water applications.
Air-to-Air Heat Pump: This type of air source heat is majorly used for heating and cooling indoor spaces. Using a fan and a heat exchanger, it transfers heat between outdoor and indoor air. It releases the absorbed heat into the indoor air, providing heating. It can also be reversed to provide cooling during hot weather.
Environmentally friendly
Air source heat pumps do not use any fuel when working, will not produce open flames, and will not emit toxic and harmful waste gases. Therefore, using air source heat pumps will not cause pollution to the environment, nor will there be any safety hazards such as fire, explosion, poisoning, etc. It is a An environmentally friendly and safe heating equipment.
Energy Saving
The main energy source for air source heat pump heating is the heat in the air. Electricity is only used to drive the compressor, not the main heating energy. Therefore, the power consumption of air source heat pump for heating is very low, only ordinary energy. One quarter of an electric boiler is a very energy-saving heating device.
Flexible heating method
Flexible heating method, cold and warm double supply. There are many heating ends of air source heat pump, such as floor heating, fan coil, etc. Users can install heating ends according to their own needs. At the same time, some air energy heat pumps can provide not only heating, but also hot water and cold air.
Intelligent and Remote Control
The air source heat pump has a built-in microcomputer control and is extremely intelligent. As long as the user sets it up for the first time, the heat pump will automatically work and achieve stable operation 24 hours a day without manual monitoring. And the whole operation process is very simple, fool-like one-click operation. They can also be remote controlled through WIFI.
Can provide hot water, heating and cooling solutions
Suitable for a wide range of climates
Air source heat pump has a wide range of applications and the temperature range is from -25 ℃(45°F) to 45 ℃(81°F) . It can be used all year round and can be used normally without cloudy days, sleet, sleet and other bad weather and winter nights. It can continuously heat and provide hot water to meet the needs of users, and is suitable for hot water projects for different groups.
Requires less space for installation
The terminal floor heating and air conditioners connected to the air source heat pump are all installed in a concealed manner. After the installation is completed, the overall appearance is beautiful and there is no problem of exposed lines and pipes. Another outdoor unit can meet the heating and cooling needs of the whole house. There will not be multiple outdoor units on the exterior wall, and it will not affect the aesthetics of the house. And due to its small size, the air source heat pump only need small area to install.
Initial cost is a little high
The main disadvantage of air source heat pumps is that the initial investment cost is high. However, from the perspective of long-term use, the use of air source heat pumps is relatively more cost-effective, and the use effect is better than other heating and cooling equipment.
Not suitable for ultra-low temperature environments
The principle of air source heat pump heating is similar to that of air conditioners. They are both heat transporters. In winter, the ambient temperature is relatively low, there is less heat in the air, and it is affected by heating and defrosting in winter.
When the outdoor temperature drops to -5°C, the heating capacity of the heat pump will decrease, causing the electricity bill to rise; when the outdoor temperature drops to -10°C, the heat pump's defrosting capacity will be weaker and the heat pump will not be drained out of the pipe in time. The water may freeze pipes and equipment.
Therefore, many people think that air source heat pumps are not suitable for places with low temperatures in winter, but this is a problem with traditional air source heat pumps. Now new heat pumps can run well in an environment of -25°C.
Ground source heat pump (GSHP), just as the name suggests, draws heat from the ground and transfers it into your home. The shallow layer of the earth's surface is a huge solar collector, which collects 47% of the solar energy, more than 500 times the energy that human beings use every year. Because of the sun radiation, heat gets stored under the earth.
Ground energy is not limited by region, resources and so on. And it is really huge, wide and ubiquitous. This kind of renewable energy stored in the shallow layer of the earth's surface is nearly infinite, which makes it become a form of clean renewable energy. GSHP takes this solar energy and circulates it round your home through a connection of pipes filled with water (or a combination of water and antifreeze).
Closed Loop Ground Source Heat Pump: This type circulates a mixture of water and antifreeze through underground pipes or loops. It extracts heat from the ground in winter and expels excess heat in summer.
Open Loop Ground Source Heat Pump: For this type, water from a well or other sources is pumped through the heat pump, where heat is absorbed. Then, the water is transferred back into the ground or into a body of water like pond.
It belongs to the utilization technology of renewable energy
Ground source heat pump is a heating and air conditioning system that uses shallow geothermal resources on the earth's surface (usually less than 400m deep) as a cold and heat source for energy conversion. Surface shallow geothermal resources can be called ground energy, refers to the surface soil, groundwater or rivers, lakes in the absorption of solar energy, geothermal energy and low temperature potential heat energy. The shallow surface of the Earth is a huge solar collector that collects 47 percent of the sun's energy, more than 500 times the total energy used by humanity each year. It is not limited by regions, resources, etc., and is truly large and wide.
High efficiency and energy saving, low operating costs
The temperature of ground energy or surface shallow geothermal resources is relatively stable throughout the year, higher than the ambient air temperature in winter, lower than the ambient air temperature in summer, is a good heat pump heat source and air conditioning cold source, this temperature characteristic makes the ground source heat pump operating efficiency than the traditional air conditioning system is 40% higher, so to save energy and save operating costs about 40%. In addition, the constant temperature of the ground energy makes the operation of the heat pump unit more reliable and stable, and also ensures the efficiency and economy of the system.
A multi-purpose machine
Ground source heat pump system can be heating, cooling, but also for domestic hot water, a multi-purpose machine, a set of systems can replace the original boiler and air conditioning two sets of devices or systems. Especially for buildings with heating and cooling requirements at the same time, ground source heat pumps have obvious advantages.
Require more space and time for installation
Ground source heat pump heat exchange is carried out underground, and a well must be drilled to transfer heat. The site is not large enough to complete the entire process. Therefore, energy exchange cannot be achieved without sufficient space. Therefore, the use will be greatly restricted by the site, and some smaller houses cannot achieve ground source heat pump heating and cooling.
High investment price
The one-time investment price of ground source heat pump is very high. Its energy-saving efficiency can reach more than 40%, but the investment price is just the opposite. It is more than 40% higher than ordinary air conditioners. The high-investment part of the ground source heat pump is actually a high-return investment.
High technical requirements
The technical and experience requirements of the installation company are relatively high.
Have negative environment impact.
This disadvantage only applies to some geothermal heat pumps, especially geothermal heat pump units that use groundwater for heating and cooling. Due to the particularity of ground source heat pumps, it may cause groundwater pollution, and if the recharge is not good, it may even cause the foundation to sink.
Soil thermal imbalance
This shortcoming is currently the biggest shortcoming and shortcoming of ground source heat pumps. Due to the large land area of our country, the climate in different regions is very different. Ground source heat pumps are mainly used for cooling in the south and heating in the north. This has resulted in underground underground conditions in the north. Too much heat is consumed, and excessive heat from the south is injected into the ground, resulting in a heat imbalance. It will cause soil temperature imbalance all year round and damage the ecology.
Requires long-term maintenance
Ground source heat pumps not only require cleaning and dust removal at the indoor end, but also require overall maintenance of the system before the start of the cooling and heating seasons every year to ensure that the system can work under normal working conditions during actual use.
The first notable factor that answers the air source heat pump vs ground source heat pump debate is their working principle.
Basically, your domestic or commercial air source heat pump absorbs heat energy from the outside air via a network of tubes that are filled with refrigerant gas. The gas gets compressed, leading to the increase in temperature from cold to hot liquid. Afterward, the hot liquid is transferred through a heat exchanger, which spreads hot air around across the rooms in your building.
The ground source heat pump works similarly to the ASHP, except that it extracts air from the ground. Pipes are installed underground (either vertically or horizontally) and refrigerants inside help to absorb heat energy that’s naturally stored under the ground. In the heat pump, the warm refrigerant is compressed and passes through a heat exchanger, which spreads hot air across the room in your building.
Air source vs ground source heat pump efficiency can simply be differentiated using how they generate heat energy. ASHP uses heat energy sourced from surrounding air, which varies depending on the time of the day and season of the year. They can be very problematic during winter when you need heating the most because the air which is the source of energy is at its coldest. This means that for the heat pump system to work, it will have to use more electricity.
The ground, which is the source of heat energy for GSHP, maintains a constant temperature throughout the year. The average ground temperature in winter is considerably higher than the air temperature. Thus, there is usually no spike in the amount of electricity used as ground source heat pumps don’t need to work too hard to generate heat energy.
The power consumption of ground source heat pump unit can be reduced by more than 40% compared with air source heat pump; It can be reduced by more than 70% compared to electric heating, and its heating system is on average nearly 50% more efficient than gas boilers and 75% more efficient than oil furnaces.
Air source heat pump installation is relatively straightforward and less invasive. It’s installed above ground level and requires minimal excavation. The outdoor unit is often placed at the exterior of a building either on the wall or a concrete slab. Typically, ASHP is easier and quicker to install.
An informed decision can be made with ground source heat pumps vs air source heat pumps installation method because GSHP systems require a ground loop setup, which involves burying a network of pipes under the ground. This can be done in 2 methods: vertically in boreholes or horizontally in trenches. Each of these methods require complex processes and excavation.
Another factor that helps with the air heat pump vs ground source comparison is product lifespan. Air source heat pumps, including heat pumps for swimming pools, tend to last for about 10 years because of their exposure to external elements, like wind, rain, and cold. If heat pumps are well maintained, they can last 15-20 years. In fact, it is advised not to install an ASHP close to the coast because the saltwater from the sea can cause the heat pump’s internal components to rust and stop functioning.
Ground source heat pump, on the other hand, is installed under the ground, where it is protected from environmental damage and even theft. The heat pump system has a design life of 20 years and the buried ground array can last over 100 years.
Air source heat pump vs ground source can also be differentiated based on their ambient temperature. ASHPs are best-suited for moderate climates. Common heat pumps are less efficient in extremely cold conditions and even stop working. But SPRSUN cold climate heat pump can operate even at -30℃.
GSHPs, on the other hand, depend on the ground’s stable temperature, which is relatively constant year-round. This makes ground source heat pumps operate efficiently in all climates, including extremely cold winters to hot summers.
Suppose traditional refrigerants are used in air source heat pumps. In that case, they will destroy the ozone layer, trigger the greenhouse effect, and have adverse effects on the atmosphere and the human living environment. But under the new technical conditions, SPRSUN use R290 as heat pump refrigerant.
R290 is a naturally occurring refrigerant in nature. Its ODP is 0. It does not damage the ozone layer and has negligible impact on global warming. It is an internationally recognized environmentally friendly refrigerant. R290 refrigerant has small flow resistance, low pressure and low refrigerant injection volume, which can achieve ultra-high energy efficiency and reach the highest energy efficiency grade of A+++ in the European standard.
According to the Standard Assessment Procedure (SAP) and how the heat pump systems work, ground source heat pumps emit less carbon, making the environment more sustainable. Significant environmental and economic benefits when the ground source heat pump unit is running, it does not consume water or pollute water, and does not need a boiler, no exhaust gas, waste residue, waste water discharge.
Cooling tower, also does not need to pile fuel waste site. Environmental benefits are significant. However, when the ground source heat pump system is abandoned, the underground heat exchange pipeline cannot be removed for treatment, which will cause underground pollution in the well drilling area. This means that the more efficient a heating system is, the lower its carbon intensity.
Depending on your desired application, is ground source better than air source heat pump?
Ground source heat pumps are best suited for specific applications where efficiency and performance are most significant, such as:
Heating and cooling larger residential buildings or commercial establishments.
Providing consistent heating and cooling solutions for spaces with high energy demands.
Suitable for institutions like schools, hospitals, and hotels, where long-term heat pump cost savings can outweigh initial installation expenses.
Because of their high energy efficiency, ground-source heat pumps are favored in regions with stringent environmental regulations and sustainability goals. They can be used in hotels, residential areas, apartments, factories, shopping malls, office buildings, schools and other buildings, small ground source heat pump is more suitable for villa residential heating, and cooling.
Air source heat pumps are versatile and suitable for various applications, like:
Providing hot water heating and cooling solutions for residential homes.
Heating or cooling individual rooms.
Provide support for heated swimming pools.
Supplementing traditional heating systems like furnaces or electric resistance heaters.
Good for commercial applications like offices, retail spaces, and small to medium-sized buildings.
Air vs ground heat pump, what are their rebate status? Rebates for air source heat pumps vary by location and may be available through federal, state, or local energy efficiency programs. These rebates often incentivize homeowners and businesses to choose ASHPs in order to reduce energy consumption and greenhouse gas emissions caused by traditional heating systems. Rebates for ASHPs are more widely available due to their common residential and commercial use.
On the other hand, GSHPs have more substantial rebates and incentives because of their higher energy efficiency and environmental benefits. However, they vary by region and might be limited to specific applications or require strict compliance with specific efficiency standards. While GSHPs rebates are more substantial, they are less common than ASHPs.
But both of them can get rebates. Since January 2023, Germany has set an additional 5% incentive for heat pump products using natural refrigerants, but it cannot be superimposed with the 5% incentive for "renewable energy", so in theory the maximum subsidy after superposition can cover 40% of the total cost. However, this is not to say that relatively common air source heat pumps do not have the opportunity to fully subsidize, if the air source heat pump uses a more environmentally friendly natural refrigerant like R290, then the air source heat pump still has the possibility of 40% subsidies.
In order to facilitate friends to have a more intuitive understanding of the above superimposed results, the following table information is summarized into several combined results, you can combine their actual situation to make comparisons and references:
- 25% cash gift, heat pump to replace old burning furnace;
- 35% cash gift to replace old fuel stoves with functional oil stoves;
- 35% cash gift to replace old combustion furnace with gas furnace, used for at least 20 years;
- 40% cash gift, new heat pump equipment is ground source, water source, ice source heat pump technology. Or new heat pump equipment using natural refrigerant materials.
What is the space requirement between air vs ground source heat pumps?
An air source heat pump is shaped like an air conditioner, installed outside the building, next to the wall. When the ASHP only has the outdoor unit, it is called MONOBLOCK, but when it comes with an indoor and outdoor unit, it is called SPLIT SYSTEM. The heat pump size that will be used depends on the size of your building and the demand for heat. Hence, you will need to discuss this with your air source heat pump supplier to buy the perfect air source heat pump size or power.
Ground source heat pump installation requires GROUND LOOP, which can be set up horizontally or vertically. This will take up some ground space and you need to check if it’s possible to easily dig the ground. In cases where the landed spaces available is limited, you can use boreholes but this will significantly increase your installation costs. While a small or medium-sized building will use one borehole, a bigger property will need at least 2 boreholes with pipework.
In general, ground source heat pumps require a larger garden site to install; while air source heat pump only need a small space to install.
The noise level is another crucial factor when considering ground source vs air source heat pump systems.
GSHPs are known for their low-noise operation because the ground loop or boreholes used are installed underground, away from inhabited spaces.
ASHPs, on the other hand, generate some noise during operation primarily from the outdoor unit. However, modern air source heat pumps are integrated with noise reduction features like variable speed compressors, sound insulations, and fitted paddings, to minimize noise level. Despite this, they can still produce a noticeable hum or fan noise, especially when working at high speed.
So if you need an air source heat pump with super low noise, you'd better find a reliable manufacturer like SPRSUN. With two testing labs, SPRSUN ensures heat pumps operate with super low noise of 49dB(A).
Another salient factor worth considering when comparing air source vs ground source heat pump is their heat output.
The coefficient of performance (COP) is an important data for the heating efficiency of a heat pump. COP depends on how much heat an air source heat pump can produce per unit of energy used. For example, an air source heat pump with COP 4 can generate four units of heat for every unit of electricity consumed.
The higher the COP, the more efficiently the heat pump will operate. Gas fired boilers/furnaces may have efficiencies below 100%, while air source heat pumps typically have efficiencies over 400% (COP over 4). While our air source heat pump COP can reach more than 5, and the energy consumption standard reaches A+++.
And different ambient temperatures will affect the COP data of the air source heat pump, for example, at an external air temperature of 2°C (35°F), the air source heat pump can operate at a COP of 3.3, while at an external temperature of 7°C (44°F), the ASHP can operate at a COP of 4.4. The reason for this difference in COP is due to the temperature difference, because at lower outdoor temperatures, the heat pump will require a larger electrical input to produce the same level of output heat.
On the other hand, the ground source heat pump maintains its reliability during every season, including summer and winter. The ratio of ground source heat pump between its heat production/cooling capacity and the electric power consumed is higher than 4.0 on average throughout the year, and it can get more than 4 kilowatts of heat if it inputs 1 kilowatt of electric energy.
The amount of heating energy consumption is reduced by 50-70% compared with other heating methods. Usually ground source heat pumps consume 1kWh of energy, and users can get more than 4kWh of heat or cold.
Renewable Heat Incentive (RHI) is a scheme formed to encourage private households, communities, and businesses to install renewable energy technologies like biomass boilers, solar water heating, and air & ground source heat pumps, with the benefit of getting financial support. Thus, when evaluating which is better between ground vs air source heat pump, consider this.
The highest RHI comes from ground source heat pumps because their output is 4 times larger than the energy required to run them and they emit lower carbon. The RHI payment is 21.16 pence/kWh, meaning the initial cost can be recovered in 5-6 years of use. This is an attractive option for individuals looking to reduce their carbon footprint and energy bills.
On the other hand, ASHPs offer 10.85 pence/kWh, which is roughly half of what GSHPs get. Although, the cost of air source heat pumps are lower, so the initial investment can also be recovered during the lifespan.
Heat pump prices depend on size, system efficiency, brand and source (air-to-air, water to air, geothermal, dual fuel, small shunt). It depends on system size, number of regions, and brand quality. Air source vs ground source heat pump other cost can be differentiated using two parameters – running cost and installation cost. The heat pump installation cost depends on your home's size, local labor costs, whether the home has plumbing, existing HVAC type, auxiliary heating, permits, and other required materials.
In comparing the installation cost of air source heat pump vs ground source heat pump, the former is cheaper to install. You only have to pay for the heat pump unit. The size of the building has no significant impact on the installation cost. The cost of an air source heat pump falls within the range of $4,000 to $8,000
Ground source heat pump, on the other hand, has a greater installation cost that falls within the range of $15,000 to £35,000 for the unit. Also, there will be extra expenses relating to the installation method that will be used (either vertical or horizontal). If you opt for a vertical installation method, which involves digging boreholes, you will spend more. Setting the pipe array in horizontal trenches is relatively cheaper.
In comparing the running cost of ground source heat pump vs air source heat pump, the former is cheaper. The higher efficiency of the ground source heat pump is beneficial in the long run because there won’t be a spike in electricity cost, as the temperature of the ground is stable year-round.
But an air source heat pump has lower efficiency, when it needs to draw heat from colder climates. This leads to higher electricity cost, eventually increasing the running cost. But this depends on brand and product technology. With the development of DC inverter technology, air source heat pump has increased efficiency, consumes less energy, and can help reduce energy bills.
Deciding which is better between air source heat pump vs ground source heat pump is dependent on the factors we’ve highlighted above. To help you make a solid decision, here is a summary.
Alt Text: Photo of Ground Source Heat Pump and Air Source Heat Pump
If you live in a climate up to -30℃(-54°F), then an air source heat pump is good for you. It will be reliable as it won’t be negatively affected by the harsh temperature of the winter season.
If you have only a small space available, choose ASHP. This is because it requires less space and the installation process is straightforward.
If you are making the decision on a tight budget, go for an air source heat pump.
If you are looking for a higher efficient heat pump system that can work greatly in all weather, including hot and cold, choose ground source heat pump.
GSHP can only be used by homeowners with a larger plot of land, with an extremely big free space. The excavation isn’t dramatic but having the extra space to ensure smooth installation is crucial.
If you are looking for a heating system that can last for a very long time, GSHP is your go-to option. It can last for about 20 years.
Using modern production processes, as well as high-quality materials sourced from industry-leading suppliers like Panasonic, CAREL, Grundfos, Copeland, Mitsubishi, Schneider, and SANYO, we've changed the notion about air source heat pumps and made up for the shortcomings of traditional heat pumps. Our air source heat pumps are no worse than ground source heat pumps.
At SPRSUN, we equip our heat pumps with advanced DC inverter technologies that make them perform efficiently under any condition. Our cold climate heat pumps are professionally manufactured to extract heat efficiently during winter. You can contact us now to get your air source heat pump with high performance.
