In brief: Yes, many modern air-to-water and air-to-air heat pumps can cool your home in summer. They use the reversed refrigeration cycle to transport heat from indoors to outdoors. This active cooling provides a high level of comfort. Passive cooling via the ground or groundwater is even more energy-efficient.
Heat Pump as Air Conditioning: Double the Benefits for Your Home
Your heat pump does more than heat your home in winter. In summer, it becomes an efficient air conditioning system. You save on purchasing a separate unit and reduce your energy costs. This dual function makes modern home technology future-proof.
We show you how cooling works. You will learn the differences between active and passive cooling. You will also find out what to consider when planning and operating the system. This will help you choose the right solution.
How does cooling with a heat pump work?
The principle is the exact opposite of heating mode. When heating, the heat pump extracts heat from the outdoor air, the ground or groundwater. It raises this energy to a higher temperature level and transfers it to the heating system.
In cooling mode, this cycle runs in reverse. The heat pump now extracts heat from the rooms. It transfers this energy outside. The refrigerant circulates through the system in the opposite direction.
How the reversed refrigeration cycle works
A four-way valve in the unit reverses the flow direction of the refrigerant. The evaporator becomes the condenser and vice versa. In the indoor unit or underfloor heating pipes, the refrigerant now evaporates, removing energy from the room air.
The resulting refrigerant vapor is drawn in by the compressor. The compressor compresses it, increasing the pressure and temperature. The hot vapor reaches the outdoor unit. There, it condenses again and releases the heat into the surroundings.
Pro tip
Have the cooling function included during the planning phase. The control technology and hydraulics must be designed for it. Retrofitting is often more expensive and technically complex.
You measure efficiency in cooling mode using the SCOP rating. It stands for Seasonal Coefficient of Performance. A high SCOP value means lower operating costs. Compare this rating across different units.
What types of cooling are available?
You can choose between active and passive cooling. Active cooling uses the compressor. Passive cooling requires little or no compressor operation. Your choice depends on the type of heat pump and the geological conditions.
Active cooling: The compressor is running
This method is mainly used by air-to-water heat pumps. The refrigeration cycle runs actively in reverse. The compressor consumes electrical energy. Output is high and adjustable.
This allows you to achieve a precise room temperature. The air is also dehumidified. This increases comfort on humid days. Make sure you have good heating pipe insulation to prevent condensation.
Active cooling via a reversible air-to-water heat pump is the most common solution for existing buildings. It offers a high degree of flexibility and is comparatively easy to retrofit.
Passive cooling: Harnessing natural cold
This elegant solution only works with geothermal probes or groundwater heat pumps. It uses the consistently low temperature of the ground or groundwater of about 10 degrees Celsius.
The circulation pump moves the cooling water through the underfloor heating system. Heat from the rooms flows directly into the cold ground. The heat pump compressor remains switched off.
Energy consumption is extremely low. You only use energy for the pumps. However, cooling output is limited by the ground temperature. You cannot achieve temperatures as low as with active cooling.
Important note
With passive cooling, condensation can form on cold pipes. This condensate must be drained reliably. An incorrectly sized home drainage pipe system can cause moisture damage. Plan for a condensate drain.
Which types of heat pumps can provide cooling?
Not every system is suitable for cooling. The technology and heat source are decisive factors.
Air-to-water heat pump with cooling module
Most modern units offer cooling as an option. You often need a separate cooling module. Cooling is usually provided actively through underfloor heating or special fan coil units.
The flow temperature remains above the dew point. This prevents condensation on the floors. Cooling output is good and easy to control. Noise from the outdoor unit can be disruptive in summer.
Ground-source and groundwater heat pumps
These systems are ideal for passive cooling. They use the heat source's constant year-round temperature. Efficiency is exceptionally high.
Initial costs are higher because of ground drilling or well construction. In return, you benefit from the lowest operating costs. Cooling output is sufficient to comfortably get through hot periods in summer.
Special solutions are available for your Garden + Outdoor area. A or a more powerful can keep your swimming pool at a comfortable temperature.
The combination of a ground-source heat pump and a radiant heating and cooling system is the most efficient and comfortable way to regulate a building's temperature. It makes optimum use of physical conditions and minimizes electricity consumption.
Air-to-air heat pump as a complete air conditioning system
These systems, often known as split air conditioners, can always both heat and cool. They distribute the conditioned air directly through indoor units in the rooms.
Control is very fast and can be managed by zone. Installation is less complex than with water-based systems. They are particularly suitable for retrofitting existing buildings.
Additional advice
Combine cooling with good building insulation and external solar shading. Closed shutters or awnings significantly reduce heat gain. This means your heat pump needs to provide less cooling output and saves energy.
What are the advantages over a traditional air conditioner?
Integrating cooling into an existing heating system offers clear benefits. They go beyond simple temperature control.
Energy efficiency and low operating costs
Heat pumps achieve high efficiency levels in cooling mode. They remove around three to four times as much energy from the indoor air as the amount of electricity they consume. Conventional portable air conditioners often perform less efficiently.
Passive cooling with geothermal energy outperforms all other systems in terms of efficiency. It noticeably reduces your electricity bill in summer. This also shortens the payback period for the entire system.
One system for every season
You only need one central home technology system. This saves space, maintenance work and the purchase cost of a separate air conditioner. Everything is controlled through a single user interface.
Maintenance is also simpler. A specialist only has to inspect one system. High-quality heat pumps typically last 15 to 20 years. This is a long-term investment in comfort.
High comfort and a healthy indoor climate
Radiant cooling systems such as underfloor cooling operate without draughts. They distribute the temperature very evenly throughout the room. They also prevent dust from being stirred up.
Integrated dehumidification during active cooling helps prevent mould growth. The indoor climate feels fresh even with a moderate temperature reduction. This is ideal for sensitive areas such as a Flexa house in a child's bedroom.
Match your interior: country-style children's furniture combines well with this cosy climate.
What costs and funding can I expect?
The investment consists of several items. These are the approximate costs you should expect.
Purchase costs for the cooling function
The cooling option alone for an air-to-water heat pump costs an additional 1,500 to 3,000 euros. Prices vary depending on the manufacturer and the hydraulic components required.
An air-to-air heat pump always includes a cooling function. The costs are included in the overall package. With geothermal heat pumps, passive cooling involves hardly any additional costs. The probes and heat exchanger are already in place.
For other cooling needs around the home, a with inverter technology offers an efficient solution for beverages.
Operating costs in summer
Electricity costs depend on how you use the system, the building envelope and the efficiency of the appliance. With active cooling from an air-to-water heat pump, you can expect to pay 200 to 500 euros per cooling season.
Passive cooling reduces these costs to around 30 to 80 euros. You only pay for the circulation pump. Compare these amounts with the cost of a portable air conditioner.
Check the funding options
The Federal Funding for Efficient Buildings (BEG) supports the installation of heat pumps. However, the cooling function itself is often not explicitly eligible for funding.
Eligible costs do include the complete system technology, however. The key factor is the heat pump's efficiency in heating mode. Before commissioning the system, ask an energy adviser to confirm the total amount eligible for funding.
You should also find out about regional programmes offered by your local authority or energy supplier. Some provide grants for particularly efficient cooling systems.
What do I need to consider when planning and installing the system?
Good preparation is the key to success. You should discuss the following points with your qualified installer.
Correct sizing is crucial
Your home's cooling load is calculated differently from its heating load. Internal heat sources such as appliances and people are important, as are solar gains through windows. An oversized system cycles too frequently and becomes less efficient.
For radiant cooling, the heated surface must be large enough. Underfloor heating is ideal. Older radiators often do not provide enough surface area for effective cooling.
Adapt the hydraulics and controls
In cooling mode, cold water flows through the pipes. This can cause condensation to form. The flow temperature must always remain above the dew point of the indoor air. This requires precise control with dew-point sensors.
You may need an additional buffer tank or a separate cooling circuit. The circulation pumps must be suitable for both operating modes. Plan these details at an early stage.
Optimise maintenance and operation
Clean the filters in indoor units or air ducts regularly. Check the outdoor unit for dirt such as leaves. A professional maintenance service should inspect the system once a year.
Use smart controls. They lower the temperature at night or when nobody is at home. This saves even more energy. Take a look at our Shop for suitable helpers.
For technical experiments or your home's operational needs, you will find useful accessories in the Business supplies section.
A heat pump with a cooling function is a smart investment in the future of your home. It combines year-round comfort with outstanding energy efficiency. Find out now which option suits your building and your needs.
Frequently asked questions
- Can every heat pump also provide cooling?
- No, not automatically. Active cooling is an optional feature that you must specify when purchasing. Air-to-water heat pumps in particular often require an additional cooling module. Check the technical specifications or ask your installer.
- How much does cooling with a heat pump cost?
- Running costs are significantly lower than those of conventional air conditioning systems. Efficiency (SCOP) is higher. Depending on the system, adding a cooling function costs anywhere from a few hundred to a thousand euros. The exact costs depend on the building's insulation and how you use the system.
- What is the difference between active and passive cooling?
- Active cooling reverses the refrigeration cycle and uses electricity to power the compressor. Passive cooling uses only the cool temperature of the ground or groundwater and circulates the refrigerant with the circulation pump. Passive cooling is significantly more efficient, but is only possible with ground-source probes or groundwater wells.
- Can I retrofit my existing heat pump?
- This is often technically possible, but it is not always cost-effective. You may need a cooling module, a different heat exchanger and adapted controls. Have a specialist familiar with your specific model assess the feasibility and costs.
- Can I get a grant for a heat pump with a cooling function?
- Government funding under the BEG primarily applies to the heating function. The cooling function as an additional feature is generally not subsidised explicitly. However, eligible costs include the system technology as a whole. Clarify the details with your energy consultant before signing a contract.
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