Ground Source Heat Pump Types
Investigating strategies for reducing space heating and hot water demand is the first stage in determining the type of ground source heat pump to use.
It calls for precise measures of energy efficiency, which can be accomplished by getting an Energy Performance Certificate (EPC). Finding heat pumps that are the proper size will reduce energy usage, heat loss, and hot water requirements.
In general, ground source heat pumps are better suited for new construction than for retrofits.
The open loop system and the closed loop system are the two types of loop systems available for ground source heat pumps.
In an open loop system, heat is recovered from groundwater as it travels through a heat pump. The interior heat pump is a part of a continuous loop of pipes that the closed loop system utilizes to extract heat from the ground.
There are various kinds of closed loop systems, including:
Heat Pump Horizontal Ground Source
The horizontal trenches used to install the ground source heating system are between one and two meters deep. In rural locations where there is more available land, it is more prevalent. The area needed to build the horizontal system is determined by the heating and cooling demands of your home, the depth at which your loop will be buried, your soil’s moisture content, the climate, and the heat pump’s performance. A space of between 300 and 700 m2 is required for the typical 150 m2 dwelling.
Heat Pump Vertical Ground Source
The price of a borehole for a ground source heat pump can vary. When there is not enough space to place the pipes horizontally, a more expensive alternative is to drill vertical boreholes. In suburban homes with limited space, it is more frequently the best option. According to the ground’s composition and the amount of heat your home needs, a hole must be dug at least 6 meters deep for insulation, and the overall depth of the piping will range from 50 to 150 meters.
Pond/Lake Closed Loop System
A closed pond loop is an option as well, however it is less typical than horizontal or vertical systems. Because it needs to be close to a body of water, it is uncommon, hence an open loop system is typically preferred. When using an open loop is impossible due to low water quality, it might be advantageous.
Additional forms of Closed Loop Systems
Since there is a shortage of water, this method solely takes the closed loop (ground sealed) system into account. When selecting the best ground source heat pumps, consider the following two factors as well:
- Direct growth (DX)
It depends on a cyclical process where the refrigerant alternates between a gas and a liquid state. The process begins when the refrigerator absorbs heat and the compressors begin to draw the vapour from the suction lines.
- indirect growth
When switching to a secondary working media in freezer applications, it is frequently employed in conjunction with carbon dioxide. In other words, during the circulation of antifreeze solution or water, energy is transferred through ground heat exchange piping from or to the refrigerant circuit.
What Are the Ground Source Heat Pumps’ Efficiency Levels?
Around 3–4 kW of heat are produced for every kW of electricity the heat pump uses. This indicates that a GSHP has a Coefficient of Performance (COP) in the range of 3.5 to 4.5.
GSHP systems conserve energy by improving the seasonal effectiveness of home heating by utilizing the consistent temperature of the ground. The sun is the heat source for ground source heat pumps because it warms the groundwater, which keeps the Earth’s surface at a constant temperature.
The effectiveness of ground source heat pumps is also influenced by the kind of soil. It’s crucial to have your individual property evaluated by a specialist in order to obtain an exact estimate of efficiency because the thermal qualities of soil in the UK vary greatly by region.
Are Heat Pumps Effective in the Cold?
The external pipelines of the heat pump are buried in the ground, which maintains a generally constant temperature below one meter throughout the year. Because of this, cold weather is not expected to have a substantial impact on your heat pump’s efficiency, and if you have a vertical GSHP, even less so.
What Can We Learn About Efficiency from the COP and SCOP?
With an average between 3 and 4, ground pump systems achieve relatively high performance coefficients. The Coefficient of Performance is calculated by dividing the electrical energy input by the usable heat output.
A ground source heat pump with a COP of 4 transfers 4 kilowatts of ground heat for 1 kilowatt of energy. We advise you to look into the seasonal coefficient of performance (SCOP), which, in contrast to the COP, is a better indicator of efficiency at various periods of the year.
The SCOP will provide an average for the entire year, giving a more reliable number than the COP, which is the performance delivered at a specific instant.
Ground Source Heat Pump Installation (3 Basic Questions)
Whether a vertical or horizontal loop system is required will depend on the size of the house and the architectural standards. The excavation of the loop fields is the initial phase.
The loop is inserted into a drilled hole that has been dug 50–150 meters below the surface in order to install a vertical ground source heat pump. After that, the heat exchanger is put in place to draw heat from the ground.
In order to construct loops horizontally without having to dig deeply into the earth, a sizable portion of the land must be excavated.
How Much Room Does a Ground Source Heat Pump Need?
In order to lay 600 meters of ground loops for an ordinary family residence, which would require digging up 700 m2, horizontal GSHPs need a lot of space. Some choose to put the pipes in numerous loops, or “slinkies,” to save room, however this somewhat lowers efficiency.
Since boreholes are dug vertically into the ground, vertical systems don’t need as much surface area. The size of the system determines the depth of the borehole; an 8kW ground source heat pump system would need about three boreholes.
What is the average installation time for a ground source heat pump?
Groundwork and plumbing system installation typically take one or two days once planning, preparing, and obtaining the required clearances have been completed. In the case of a borehole GSHP, the installation may take three days depending on the geological conditions. The heat pump unit itself needs to be installed and connected to your heating system’s infrastructure before anything else.
Do Ground Source Heat Pumps Require Planning Permission?
It is significant to highlight that particular planning licenses are necessary in Wales and Northern Ireland, and that permissions in England and Scotland are location- and property-specific.
Ground Source Heat Pump Costs
The price to install a ground source heat pump in your home might range from £16,000 to $35,000. The size and insulation quality of your home will affect its operating costs. Ground source heat pumps require more money to install than other systems, but the additional expense is typically offset by the energy savings, and there are incentives available to help with the costs.
The price estimates below do not account for any wet system update because it is important to keep in mind that the cost of a ground source heat pump also relies on whether any new radiators or an entirely new underfloor heating system are necessary.
Ground Source Heat Pump Costs
The prices of groundwork for horizontal and vertical systems differ significantly. Despite being less expensive, horizontal installation needs at least half an acre of land.
Average UK savings and costs for solar panels
|Number of Rooms
|installation costs of a heat pump
|Costs of horizontal groundwork
|Costs of vertical groundwork
The prices vary from case to instance, and the figures may not reflect actual offers. They serve just as a broad guide.
How Much Money Can a Ground Source Heat Pump Save You?
The following table, based on data from the Energy Saving Trust, details the carbon dioxide and energy bill savings that may be achieved in England, Scotland, and Wales when employing a ground source heat pump. All of the stated existing systems are non-condensing systems, which are probably the systems that users want to replace.
Savings on energy bills and carbon dioxide
| Current System
| Energy Bill savings
|Savings on Carbon Dioxide
| 2100-3300 kg
| 6700-11700 kg
| 3000-4700 kg
| 2800-4500 kg
| 7600-12100 kg
What Companies Offer GSHPs?
Efficiency, cost, and brand differences exist amongst ground source heat pumps. Even while some brands’ pricing and efficiencies may be comparable, some brands are more expensive than others.
The most well-known ground source heat pump brands in the UK include Baxi, Calorex, Bosch, and Mitsubishi. There are numerous other manufacturers as well. Due to the wide range of brands accessible, it’s crucial to compare supplier quotations in order to choose the one with the best price while also making your decision.
Benefits and Drawbacks of GSHP
Contrary to popular opinion, installing a heat pump doesn’t require a lot of space. The heat of the Earth can be utilised to benefit even a little garden. When you install a heat pump, you can benefit from a variety of advantages. Additionally, there are drawbacks to be aware of with every installation:
- Of the most effective ways for heating water
- Low operating costs and upkeep
- Less noisy than air source heat pumps and gas boilers
- Low influence on the environment
- Components have a longer lifespan than those in air source heat pumps.
- High initial expenses
- Based on the horizontal system’s need for space and the type of bedrock
- They’re better suited for new construction
- Making them unsuitable for retrofits.
- When heat is transported, it’s debatable how ecologically beneficial various liquids are.
Radiators versus underfloor heating systems
The best approach to utilize your heat pump to its full potential is to combine it with radiant floor heating and ground source heat pumps.
In comparison to radiators, an underfloor heating system distributes heat evenly across the entire surface, whereas radiators must spread heat from one corner of the room to the other.
Radiators are another wonderful option that offers high performance, but they are also more expensive than underfloor heating. Heat distribution is well thought out with underfloor heating, therefore the floor system will probably have a lower output temperature than a radiator, implying a greater coefficient of performance. As a result, the SCOP is higher for underfloor heating compared to radiators.
Does the government offer GSHP grants?
The UK government’s incentives make it easier than ever to save money on heat pumps. The Renewable Heating Incentive now compensates ground source heat pumps for their energy at a rate of 21.17 pence per kWh.
Over a period of seven years, payments are made on a quarterly basis. The amount of money you get will depend on a variety of things, including as the technology you install, the most recent rates for each type of heating solution, and, in some circumstances, metering.
The Non-Domestic Renewable Heat Incentive (RHI) intends to cover the expenses associated with installing ground source heat pumps in commercial settings. The owners of the businesses and the providers of social housing profit from both short-term payback and long-term rate of return. Additionally, the UK government’s financial assistance provides a chance for modernization of both existing homes and new construction.
In 2022, the RHI is anticipated to end, and a new grant is anticipated to take its place. Unlike the RHI, this new grant—called the Clean Homes Grant—will be for installation. It is projected that this award program will go into force in April 2022.
The Energy Company Obligation is a different category of grants (ECO). Energy suppliers are required by law to continue implementing energy saving measures as a result of this subsidy. The Home Heating Cost Reduction Obligation, Community Obligation, and Carbon Emissions Reduction Obligation are the three key areas of concentration.
Last but not least, you can qualify for a VAT reduction on your ground source heat pump. You may qualify for a 5% tax discount if you are over 60 or receive income or disability assistance. You may receive a discount on the entire product or only the installation, depending on the expenses.
We can assist you if you want to get the best ground source heat pump. Simply provide your information and preferences in the contact form, and we’ll get back to you with personalized, cost-free, and obligation-free quotations!