Guide to Low Temperature Air Source Heat Pumps - Renewables Merchant

Low temperature air source heat pumps (LTASHPs) are renewable energy technology that extracts heat from the outside air to provide heating and hot water for buildings. These systems operate efficiently even at low outdoor temperatures and are designed to work with underfloor heating systems, low-temperature radiators, and fan coils. LTASHPs are crucial in modern energy solutions due to their high efficiency and low environmental impact. They help reduce reliance on fossil fuels, lower carbon emissions, and contribute to achieving energy sustainability and climate goals. With increasing energy costs and stricter environmental regulations, LTASHPs are becoming preferred for residential and commercial heating needs. This guide provides a comprehensive overview of Low Temperature Air Source Heat Pumps (LTASHPs), including their benefits, installation process, cost considerations, and suitability for different applications. It aims to inform homeowners, building managers, and policymakers about the advantages of LTASHPs and how they can be integrated into existing and new buildings to enhance energy efficiency and reduce carbon footprints.

What are Low Temperature Air Source Heat Pumps?

Low temperature air source heat pumps (LTASHPs) are advanced heating systems that extract heat from the outside air, even at low temperatures, to provide heating and hot water for buildings. Using a refrigeration cycle, they operate on transferring thermal energy from a cooler to a warmer space. This process is highly efficient, using electricity primarily to move heat rather than generate it. LTASHPs use a refrigeration cycle involving a refrigerant that absorbs heat from the outside air through an evaporator. The heat is then compressed to a higher temperature by a compressor and transferred indoors via a condenser. The heated refrigerant releases energy into the building’s heating system, typically through underfloor heating, low-temperature radiators, or fan coils. The refrigerant then cycles back to the evaporator, and the process repeats. This cycle allows LTASHPs to provide consistent and efficient heating, even in colder climates.

Benefits of Low Temperature Air Source Heat Pumps

One of the most significant benefits of Low Temperature Air Source Heat Pumps (LTASHPs) is their high energy efficiency. By utilising the ambient air as a heat source, these systems can achieve a Coefficient of Performance (COP) of 3 to 4, generating 3 to 4 units of heat for every unit of electricity consumed. This efficiency translates into substantial cost savings on energy bills compared to traditional heating systems. Over time, the initial investment in an LTASHP can be offset by the reduced operating costs, making it a financially attractive option for many homeowners and businesses. LTASHPs play an essential role in reducing carbon emissions and combating climate change. By using renewable energy from the air, they significantly lower the reliance on fossil fuels, which significantly contribute to greenhouse gas emissions. Adopting LTASHPs helps decrease the overall carbon footprint of buildings, aligning with global and national efforts to achieve net-zero carbon targets. Additionally, many LTASHPs use refrigerants with low Global Warming Potential (GWP), further minimising their environmental impact. Another advantage of LTASHPs is their flexibility and ease of integration with existing heating systems. They can be used in various residential, commercial, and industrial settings. They are compatible with different heat distribution systems, such as underfloor heating, low-temperature radiators, and fan coils. This versatility makes retrofitting LTASHPs into older buildings easier without extensive modifications. Moreover, they can work alongside other renewable energy technologies, such as solar panels, to create a more comprehensive and sustainable energy solution.

Types of Low Temperature Air Source Heat Pumps

Low temperature air source heat pumps (LTASHPs) come in various models tailored to meet different heating needs and building types. These models can be broadly categorised into monobloc and split systems:

Monobloc Systems:

These single-unit systems contain all components in one outdoor unit. They are compact and easy to install, making them suitable for residential applications.

Split Systems:

These systems have two parts – an outdoor unit and an indoor unit. The outdoor unit extracts heat from the air and transfers it to the indoor unit, which distributes the heat inside the building. Split systems are typically more powerful and versatile, suitable for larger buildings and commercial applications. When deciding on an LTASHP, consider the following key features and specifications:

  • Heating Capacity:

This is measured in kilowatts (kW) and indicates the heat the pump can produce. Select a model with an appropriate capacity for the size of your building and heating needs.

  • Coefficient of Performance (COP):

The COP measures the heat pump's efficiency. A higher COP means greater efficiency. Look for models with a COP of 3 or higher.

  • Noise Levels:

Since the pump will be running frequently, consider the noise level of the outdoor unit, especially if it will be installed near living areas. Modern LTASHPs are designed to operate quietly.

  • Refrigerant Type:

Check the type of refrigerant used in the heat pump. Low GWP (Global Warming Potential) refrigerants are more environmentally friendly and comply with current regulations.

  • Defrost Function:

In colder climates, a defrost function is essential to ensure the heat pump operates efficiently without ice build-up on the outdoor unit.

  • Integration Capabilities:

Ensure the heat pump can integrate with your existing heating system, whether underfloor heating, radiators or a hybrid system.

  • Smart Controls:

Many modern LTASHPs come with smart controls that allow you to remotely manage and monitor your heating system via a smartphone app.

Installation and Maintenance

The installation of low temperature air source heat pumps (LTASHPs) involves several key steps to ensure optimal performance:

  1. Site Assessment:
    A professional installer will assess the site to determine the best location for the outdoor unit, ensuring adequate airflow and minimal noise disruption.
  2. System Design:
    Based on the building’s heating needs, the installer will design a system that integrates the LTASHP with existing heating infrastructure, such as radiators or underfloor heating.
  3. Outdoor Unit Installation:
    To minimise vibrations and noise, the outdoor unit is mounted on a solid base, often on the ground or a wall bracket.
  4. Indoor Unit Installation:
    If a split system is used, the indoor unit is installed and connected to the outdoor unit via refrigerant lines and electrical wiring.
  5. System Integration:
    The LTASHP is connected to the building’s heating system, ensuring compatibility with thermostats and other controls.
  6. Commissioning and Testing:
    The installer will commission the system, checking for proper operation, efficiency, and potential issues.

Maintenance

Regular maintenance of LTASHPs is crucial for ensuring long-term efficiency and reliability:

  • Clean Filters:

Regularly clean or replace air filters to maintain airflow and efficiency.

  • Check Refrigerant Levels:

Ensure refrigerant levels are within the recommended range to avoid reduced performance.

  • Inspect Coils:

Clean the evaporator and condenser coils to prevent dirt build-up, which can hinder heat transfer.

  • Clear Obstructions:

Keep the area around the outdoor unit free from obstructions like leaves, snow, and debris.

  • Professional Servicing:

Schedule annual professional servicing to check for leaks, test the system’s efficiency and ensure all components are in good working order.

Challenges

  • Noise:

If the outdoor unit is noisy, ensure it is installed on a stable base and check for loose components. Soundproofing materials can also reduce noise.

  • Icing:

The outdoor unit may ice up in cold weather. Ensure the defrost function works correctly, and consider installing a weatherproof cover to protect it.

  • Reduced Efficiency:

Check for clogged filters, low refrigerant levels, or dirty coils if the system's efficiency drops. Regular maintenance can prevent these issues.

  • Inadequate Heating:

Ensure the heat pump is appropriately sized for the building. If the heating output is insufficient, it may be due to an undersized unit or incorrect settings.

LTASHPs Incentives

The government actively supports the adoption of low temperature air source heat pumps (LTASHPs) through various incentives and policies aimed at promoting renewable energy and reducing carbon emissions:

Renewable Heat Incentive (RHI):

This program financially supports homeowners and businesses that install renewable heating systems, including LTASHPs. Participants receive quarterly payments based on the amount of renewable heat generated.

Green Homes Grant:

Although this scheme has ended, it provided vouchers to help cover the cost of installing energy-efficient improvements like LTASHPs, reflecting the government's commitment to promoting such technologies.

Building Regulations and Standards:

The Future Homes Standard, set to be implemented in 2025, mandates that new homes must have low-carbon heating systems, including heat pumps, highlighting the shift towards sustainable building practices. The market for LTASHPs is experiencing significant growth due to increasing awareness of environmental issues, rising energy costs, and supportive government policies:

  • Growing Demand:

As part of the UK's net-zero targets by 2050, a concerted push exists to phase out gas boilers and adopt more sustainable heating solutions, driving demand for LTASHPs.

  • Technological Advancements:

Improvements in heat pump technology, such as enhanced efficiency and quieter operation, are making LTASHPs more attractive to consumers.

  • Industry Support:

Major manufacturers and energy companies are investing in heat pump technology, expanding product ranges, and offering installation services, which helps to boost market penetration.

  • Increased Awareness:

Educational campaigns and information dissemination by government bodies and industry stakeholders are increasing public awareness and understanding of LTASHPs, further driving adoption rates.

Comparison with High Temperature Heat Pumps

Low Temperature Air Source Heat Pumps (LTASHPs):

Operation:

Extract heat from the air and operate efficiently at lower output temperatures (25-55°C).

Efficiency:

Typically, they have a higher Coefficient of Performance (COP), ranging from 3 to 4, meaning they produce more heat per unit of electricity consumed.

Applications:

Ideal for buildings with underfloor heating or low-temperature radiators, which require lower temperature water.

High Temperature Heat Pumps (HTHPs):

Operation:

Also, they extract heat from the air but are designed to provide higher output temperatures (up to 80°C).

Efficiency:

Generally, they have a lower COP than LTASHPs due to the higher temperature outputs required.

Applications:

Suitable for older buildings with existing high-temperature radiator systems or where high-temperature water is needed for specific applications.

LTASHPs Applications:

New Builds:

Perfect for new constructions designed with modern low-temperature heating systems like underfloor heating.

Retrofits with Low-Temperature Systems:

Ideal for retrofitting into homes updated with low-temperature radiators or underfloor heating.

Energy-Efficient Homes:

It is best suited for well-insulated, energy-efficient homes where lower heating outputs are sufficient.

HTHPs Applications:

Older Buildings:

Suitable for older properties with existing high-temperature radiator systems where replacing the heating system is not feasible.

Industrial and Commercial Uses:

Useful in industrial or commercial settings where high-temperature process heating is required.

Limited Insulation Homes:

Appropriate for buildings with poor insulation where higher temperatures are needed to maintain comfort.

Cost Analysis

The initial investment for low temperature air source heat pumps (LTASHPs) can be higher than traditional heating systems, typically ranging from £6,000 to £12,000 depending on the model and installation complexity. However, the long-term savings on energy bills, due to their high efficiency (with COPs of 3 to 4), can offset these initial costs. Over time, the reduced operating costs make LTASHPs a financially attractive option, especially with rising energy prices. The Return on Investment (ROI) for LTASHPs can be calculated by comparing the initial costs against the annual savings and any financial incentives received:

Initial Cost:

Assume an installation cost of £8,000.

Annual Savings:

Estimate annual energy savings of £800 (varies based on energy prices and efficiency).

Incentives:

Consider RHI payments of £500 per year for seven years.

Total Savings Over 7 Years = (7 × £800) + (7 × £500) = £5,600 + £3,500 = £9,100

ROI = (Total Savings / Initial Cost) × 100 = (£9,100 / £8,000) × 100 ≈ 113.75%

This simple ROI calculation indicates that LTASHPs can pay for themselves in under seven years, offering continued savings and a positive return.

Choosing the Right LTASHP

  • Size and Capacity:

Ensure the heat pump is appropriately sized for your property. An undersized unit won't provide sufficient heating, while an oversized unit may cycle on and off too frequently, reducing efficiency.

  • Efficiency:

Look for models with a high Coefficient of Performance (COP). Higher COP values indicate greater efficiency and lower operating costs.

  • Climate Compatibility:

Choose a model designed to operate efficiently in your local climate, especially in an area with colder winters.

  • Noise Levels:

Consider the noise produced by the outdoor unit, especially if it will be placed near living areas. Modern LTASHPs are designed to operate quietly.

Tips for Selecting the Best Model

  • Energy Efficiency Ratings:

Check the energy efficiency ratings and certifications, such as the Energy Performance Certificate (EPC) and Microgeneration Certification Scheme (MCS).

  • Smart Controls:

Opt for models with smart control features for remote monitoring and management, which can enhance convenience and efficiency.

  • Compatibility:

Ensure the LTASHP is compatible with your existing heating system, whether underfloor heating, low-temperature radiators, or a hybrid system.

  • Warranty and Support:

Consider the manufacturer's warranty and the availability of after-sales support and maintenance services.

Questions to Ask Suppliers/Installers

1. What is the expected COP and seasonal performance of this model? 2. Is the unit compatible with my existing heating system? 3. What are the installation requirements and costs? 4. What type of maintenance is required, and how often? 5. Are any additional features, such as smart controls, included? 6. What warranties and after-sales support do you provide? 7. Can you provide references or case studies of similar installations?

FAQs

Q: What is a Low Temperature Air Source Heat Pump (LTASHP)?

An LTASHP is a heating system that extracts heat from the outside air at low temperatures to provide heating and hot water for buildings. It operates efficiently even in colder climates.

Q: How does an LTASHP work?

An LTASHP uses a refrigeration cycle to absorb heat from the air, compress it to a higher temperature, and transfer it indoors via an evaporator, compressor, and condenser.

Q: Are LTASHPs suitable for older buildings?

Yes, LTASHPs can be integrated into older buildings, especially if they have been retrofitted with low-temperature radiators or underfloor heating.

Q: What are the benefits of using an LTASHP?

Benefits include high energy efficiency, lower carbon emissions, energy bill savings, and compatibility with various heating systems.

Q: How much does an LTASHP cost to install?

The installation cost of an LTASHP ranges from £6,000 to £12,000, depending on the model and installation complexity.

Q: What maintenance is required for an LTASHP?

Regular maintenance includes cleaning filters, checking refrigerant levels, inspecting coils, and ensuring the area around the outdoor unit is clear of obstructions. Annual professional servicing is also recommended.

Q: Can I get financial incentives to install an LTASHP?

Yes, the UK government offers incentives like the Renewable Heat Incentive (RHI) to help offset the cost of installing an LTASHP.

Q: How long does it take for an LTASHP to pay for itself?

With energy savings and potential incentives, an LTASHP can pay for itself in under seven years, offering continued savings.

 

Related Articles