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- Product Selector
Air Source Heat Pumps (ASHP)
Air source heat pumps (ASHPs) are energy-efficient systems that use the heat transfer properties of refrigerants to heat or cool buildings. They work by absorbing heat from outside air, compressing it into a low-pressure, low-temperature gas, and releasing it through a condenser coil inside the building. The heated air is distributed throughout the building via a forced air distribution system or a hydronic system. In cooling mode, the process can be reversed to remove heat from indoor air. ASHPs are highly efficient because they move heat instead of generating it, which consumes less energy. They can provide both heating and cooling functions, making them versatile for year-round comfort. They are particularly effective in moderate climates but can also be used in colder climates with supplemental heating elements or more advanced models designed for cold weather operation.
COP
• Because Heat Pumps operate using electricity, you need to be certain that the heat energy you gain from the earth or air significantly exceeds the operating electrical energy. The ratio between heat gained and electricity expended is called the ‘Coefficient of Performance’ (COP).
• You should look at getting a COP ratio of 3.0 or above. Verify with the manufacturer/supplier that their equipment achieves this ratio consistently.
• Heat pumps should not be used to provide Domestic Hot Water (DHW) in conjunction with Electrical Immersion Heaters. The overall electricity load will be immense - effectively derailing your low energy project.
Retrofitting an ASHP
Retrofitting an Air Source Heat Pump (ASHP) to a house in the UK involves several steps to ensure the system is installed correctly and efficiently. ASHPs are a sustainable and energy-efficient way to heat homes, but the installation process can be complex and should ideally be carried out by a qualified installer. Here's a general overview of the retrofitting process:
1. Assessment and Planning:
Hire a, preferably, Microgeneration Certification Scheme (MCS) - qualified ASHP installer or engineer to assess the building and determine if it is suitable for an ASHP system. Factors such as insulation, the size of the building, and the heating needs will be considered.
2. System Design:
Based on the assessment, the installer will design a suitable ASHP system. This includes selecting the right ASHP unit size, determining the best location for the outdoor unit (the heat pump), and planning the heated air or water distribution system.
3. Planning Permission and Regulations:
Check whether planning permission is required or if the ASHP installation falls under Permitted Development Rights. Also, ensure compliance with building regulations. The installer should be aware of these requirements.
4. Insulation and Efficiency Measures:
Before installing the ASHP, it's crucial to ensure the house is well-insulated. Proper insulation helps the ASHP work more efficiently and reduces heat loss. This might include insulating walls, roofs, and floors.
5. ASHP Installation:
The ASHP unit is typically installed outside the building. The indoor components are also installed, including the heat distribution system (radiators, underfloor heating, or a hot water tank). The installer will connect the two components with insulated pipes.
6. Electrical Connections:
ASHPs require electrical connections. It's important to determine whether the existing electrical system can handle the additional load and upgrade it if necessary to meet the requirements.
7. Commissioning and Testing:
The ASHP system should be commissioned and tested to ensure it's working correctly. This includes checking for leaks, verifying the system's efficiency, and fine-tuning settings.
8. Maintenance and Servicing:
ASHPs require regular maintenance to ensure optimal performance. It's important to schedule annual servicing with a qualified technician.
9. Monitoring and Control:
Consider smart controls allowing residents to monitor and control the ASHP remotely. This can help optimise energy usage and comfort.
10. Government Incentives:
The Government is keen to move forward with Heat Pumps. Check for incentives or grants available for installing renewable heating systems like ASHPs. These incentives can help offset the installation costs.
11. Ensure that instructions on how to get the best from the system are provided:
Residents must know how to use ASHP effectively, including adjusting settings based on their heating needs and the weather.
12. Monitor Energy Usage:
Once installed, monitoring energy bills and energy consumption is a good idea to assess the system's performance and identify any potential issues.
Remember that the specific steps and requirements can vary depending on location, building type, and existing heating system.
But beware ......
Heat pumps are generally considered an energy-efficient and environmentally friendly heating and cooling option, but they are not without their drawbacks and limitations. Here are some common issues and drawbacks associated with heat pumps:
1. Temperature limitations:
Heat pumps become less efficient as the outdoor temperature drops. In very cold climates, they may struggle to provide sufficient heat and supplemental heating sources may be needed.
2. Initial cost:
Heat pumps can be more expensive to purchase and install than traditional heating like gas or oil boilers. However, they can often pay for themselves over time through energy savings.
3. Installation challenges:
Proper installation is crucial for efficiently operating a heat pump. Not all houses are well-suited for heat pump installation.
4. Noise:
Heat pumps can be noisy, especially when the compressor or fan runs at high speed. This noise can be a nuisance, particularly if the unit is near bedrooms or quiet areas.
5. Maintenance:
Heat pumps require regular maintenance to operate efficiently. This includes cleaning filters, checking refrigerant levels, and inspecting electrical components.
6. Environmental impact of refrigerants:
Some heat pumps use refrigerants with a high global warming potential (GWP), which can contribute to climate change if they leak. However, newer heat pumps are designed to use more environmentally friendly refrigerants with lower GWPs.
7. Lifespan:
The lifespan of a heat pump may be shorter than that of some other heating and cooling systems. Proper maintenance can extend the system's life, but eventual replacement may be necessary.
8. Electrical requirements:
Heat pumps require electricity to operate, which may increase your electricity bills, especially if electricity is more expensive in your area.
9. Backup heating:
In very cold climates, heat pumps may need a backup heating source, which can add to the complexity and cost of the system.
10. Compatibility:
Heat pumps may not be compatible with existing ductwork or heating systems in some homes, requiring additional modifications or expenses.
It's important to note that many of these drawbacks can be mitigated or overcome with proper planning, installation, and maintenance. The suitability of a heat pump for specific needs depends on factors like climate, the existing infrastructure in the home, and budget.
