What is an air-water heat pump?
Air-water heat pump a heating and cooling system that utilizes the thermal energy of outside air, and that by means of water transfer it to the building's heating system. This solution allows for a single system:
- provide heating,
- be suitable for cooling,
- and produce domestic hot water (DHW).
Air-water heat pumps are one of the most popular types of heat pumps today. most common heat pump solution family homes, as it does not require soil drilling or well construction, yet is capable of serving the energy needs of an entire building.
How does an air-to-water heat pump work?
Extracting heat from the air
The outdoor unit of the system extracts heat from the ambient air. This heat:
- is present even at low external temperatures,
- and can be utilized with the help of a closed refrigerant circuit.
The refrigerant can evaporate even at low temperatures, allowing it to transfer heat energy absorbed from the air to the inside of the system.
Heat transfer to the heating system
The absorbed heat is transferred to the water in the heating system via a heat exchanger.
This heated water circulates:
- in underfloor heating,
- in radiators,
- in fan coil units,
- and in the domestic hot water tank.
The use of water as a medium makes the air-water heat pump central heating system, as opposed to air-to-air solutions.
What can an air-to-water heat pump be used for?
Heating
The primary function of an air-water heat pump is heating. The system:
- works most efficiently with low-temperature heating systems,
- Particularly well suited for underfloor heating and wall heating.
However, with proper planning:
- can also be used with modern radiators,
- Can also be installed during renovations.
Cooling
Many people are unaware that air-to-water heat pumps also suitable for cooling. In this mode, the system draws heat from the interior and releases it into the outside air.
Cooling can be achieved by:
- fan coil units,
- through floor or wall surfaces (surface cooling).
However, proper regulation and humidity control are important to prevent condensation.
Domestic hot water (DHW)
The air-water heat pump can also meet daily hot water demand with the help of a separate DHW tank.
This means that a single system can replace:
- the boiler,
- the boiler,
- and partly the climate as well.
Why is this type of heat pump so popular?
The popularity of air-to-water heat pumps stems from several factors:
- no drilling or major earthworks required,
- can be installed more quickly than ground source heat pumps,
- can be easily combined with existing heating systems,
- Particularly effective solution in combination with solar panels.
For these reasons, it is often the first choice for those who:
- are looking for a modern, electric-based heating system,
- I would like to reduce fossil fuel consumption,
- think long-term about the energy supply for their property.
Advantages and disadvantages of air-water heat pumps
Advantages – why do so many people choose it?
One of the biggest advantages of air-to-water heat pumps is that complex system serving the entire house It works. A single device can replace a traditional boiler and, with the right design, can also cover some of the cooling needs.
The advantages include:
- Uses renewable energy sources
The system utilizes the heat content of the ambient air, thereby significantly reducing fossil fuel consumption. - Can ensure lower operating costs
In particularly well-insulated buildings, electricity consumption is favorable, especially when combined with a solar panel system. - Versatile application
It is suitable for heating, cooling, and domestic hot water production, eliminating the need for multiple separate devices. - Easily integrated into existing systems
During renovations, it can often be integrated into existing radiator heating systems, provided it is correctly sized. - No need for soil drilling or wells
This greatly simplifies installation compared to soil- or water-based systems.
Disadvantages – when is it not the ideal choice?
An air-to-water heat pump is not the best solution in every situation. It is important to be aware of its limitations.
The main disadvantages:
- Weather-dependent efficiency
In cold outdoor temperatures, the efficiency of the system may decrease as less heat can be extracted from the air. - Appropriate heat sinks are required
In the case of old radiators requiring high flow temperatures, the efficiency of the system may deteriorate. - Noise emission of outdoor unit
The placement of the outdoor unit must be carefully planned, especially in densely built-up areas. - Higher investment costs than for a boiler
Although it may pay off in the long run, the initial investment is significant.
Efficiency and performance – what do the numbers mean?
Interpretation of COP and SCOP values
The efficiency of air-to-water heat pumps is generally characterized by COP (Coefficient of Performance) and SCOP (Seasonal COP) values.
- COP: efficiency measured in a given operating condition
- SCOP: average efficiency over an entire heating season
The higher these values are, the more efficiently the system operates.
However, it is important to note that manufacturer data is based on ideal conditions, and actual efficiency depends on the design of the building and the system.
What affects efficiency?
The efficiency of an air-to-water heat pump is influenced by several factors:
- outside temperature,
- flowing water temperature,
- type of heat sinks,
- building insulation,
- quality of regulation.
Therefore, it is crucial to professional design and dimensioning.
What types of buildings are air-to-water heat pumps ideal for?
Newly built family homes
For new construction, the air-to-water heat pump:
- ideal for buildings with low heating requirements,
- Combined with underfloor heating, it ensures high efficiency.
Properties under renovation
Renovations often require modernization of the heating system, replacement of radiators, or expansion of heat emitters. However, with proper planning, the system can be made functional even in older buildings.
Typical compromises and decision-making criteria
When choosing an air-to-water heat pump, the following should be considered:
- investment costs vs. long-term savings,
- comfort requirements,
- noise level,
- available electrical capacity.
These factors determine whether the system will actually be a good choice for the property in question.
Installation of air-water heat pump
Main steps of installation
Installing an air-to-water heat pump is a more complex process than installing a conventional boiler, but it does not require the same amount of groundwork or permits as ground-source or water-source systems.
Typical installation steps:
- Heat demand calculation and system design
This determines the required performance and suitability of the heat sinks. - Outdoor unit placement
Proper ventilation, noise protection, and frost protection are important. - Installation of indoor unit and hydraulic components
This includes the buffer tank, DHW storage tank, and control system. - Electrical connection and control settings
- Trial operation and fine-tuning
Accurate installation has a fundamental impact on the subsequent efficiency and service life of the system.
Placement considerations and noise level
The placement of the outdoor unit is a critical issue. The following must be taken into account:
- the proximity of neighboring properties,
- surfaces causing reflective noise,
- wind direction and snow accumulation.
Modern air-to-water heat pumps are relatively quiet, but if they're not placed properly, the noise can be annoying.
Sizing – why is it a key issue?
Lack of proper sizing:
- excessive energy consumption,
- for frequent switching on and off,
- can lead to a reduced lifespan.
The following must be taken into account during dimensioning:
- heat loss from the building,
- the desired level of comfort,
- the type of heat sinks,
- hot water demand.
Oversizing can be just as problematic as undersizing.
Maintenance and service life
Maintenance requirements are generally lower than for a conventional boiler, but cannot be neglected.
Regular monitoring includes:
- checking the condition of the coolant,
- cleaning of filters,
- inspection of hydraulic components,
- control update.
With proper maintenance, the system will operate reliably over the long term, with a service life of up to 15-20 years.
Comparison of air-water heat pumps with other solutions
With air-to-air system
The advantages of air-to-water heat pumps are:
- operates as a central heating system,
- also produces hot water.
In contrast, the air-to-air solution:
- simpler,
- cheaper,
- but more limited in its functions.
Soil- and water-based systems
The air-water system:
- requires less investment,
- can be installed more quickly.
Soil- and water-based systems:
- provide more stable efficiency,
- can offer lower operating costs in the long term.
Summary – when is an air-to-water heat pump a good choice?
An air-to-water heat pump may be the ideal choice if:
- It is a modern, well-insulated building.,
- low-temperature heat sinks are available,
- the use of renewable energy is important,
- There is no possibility of drilling or wells.
However, this is not always the best solution, so the final decision should always be made by expert planning must precede.
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