Air-to-water systems are a type of system mainly used for space conditioning, both in residential and commercial applications. These systems use air as the thermal energy source and water as the heat transfer fluid to distribute energy within the building. Dedicated heat pumps are used, representing an efficient, environmentally friendly, and increasingly widespread solution for heating, cooling, and the production of domestic hot water (*).
Operating principle
The air-to-water heat pump extracts heat from the outdoor air (even at low temperatures) and transfers it to the water circulating in the distribution system.
During the summer cycle, the air-to-water heat pump reverses its operation: instead of extracting heat from the outside to heat indoor spaces, it removes heat from indoor areas and transfers it to the outdoor air, thus allowing space cooling.
Main components
- Outdoor unit: contains the compressor, heat exchanger (evaporator), expansion valve, and fans.
- Indoor unit or hydronic module: contains the heat exchanger (condenser), circulation pump, expansion vessel, and, if required, an auxiliary electric heater.
- Storage tank (optional): for domestic hot water or thermal inertia.
- Distribution terminals: such as radiant panels, fan coil units, or low-temperature radiators.
Applications
Air-to-water systems are used in various contexts:
- Residential: single-family homes, apartments, condominiums.
- Tertiary sector: offices, shops, schools, hotels.
- Commercial: warehouses, laboratories.
Thanks to their versatility and ease of installation, they are often used in new buildings or in major renovations with advanced thermal insulation.
Advantages of GSI heat pumps
- High energy efficiency (COP > 3 in many cases).
- Reduced CO₂ emissions.
- Use of renewable sources (ambient energy).
- Compatibility with low-temperature systems.
- Reversible operation (heating/cooling).
Design constraints
- Reduced performance at very low outdoor temperatures.
- Noise: outdoor units may generate noise.
Air-to-water systems represent a technologically advanced and sustainable solution for integrated building climate control. When properly sized and combined with low-temperature systems, they can ensure high comfort levels and significant energy savings. Their adoption is expected to grow as part of the energy transition and the decarbonization of the building sector.
(*) DID YOU KNOW…
MAGIS is an innovative system integrated into GSI heat pumps that recovers heat normally dissipated by the compressor to produce domestic hot water continuously and automatically, without interrupting indoor comfort. This helps reduce energy waste and lower utility bills, ensuring significant economic savings.
