Underfloor cooling: how it works, consumption and costs

Underfloor cooling is a summer air-conditioning system that uses the same infrastructure as radiant heating to cool rooms uniformly, without direct air flows and with limited consumption.

Completely integrated into the structure of the home, it does not require visible units or elements installed on the walls, leaving full freedom in the arrangement of rooms. It is a solution designed for those seeking constant and silent well-being, not just a rapid reduction in temperature.

How underfloor cooling works

Underfloor cooling acts by radiation, not by convection. Water at a controlled temperature circulates in the pipes embedded in the screed. The floor surface, kept cool, absorbs the radiant heat emitted by bodies and objects in the room, lowering the perceived temperature progressively and uniformly.

This principle differs from the operation of air conditioners, which cool the air by forced convection, generating direct flows. The radiant system does not produce air currents, does not raise dust or allergens and does not generate noise in the rooms.

To produce water at the temperature required for cooling, the system requires an air-water heat pump: a generator that extracts heat from the water by using the thermal energy of the outside air. Working with less extreme water temperatures than those required by traditional air conditioners, the heat pump consumes less energy for the same comfort produced.

Why dehumidification is mandatory

Underfloor cooling cannot function correctly without a humidity control system. The reason is technical: the radiant system cools surfaces but does not extract humidity from the air, unlike air conditioners, which also manage the latent load. In the absence of dehumidification, two problems occur:

1. Perceived comfort: in summer, discomfort is often caused by humidity more than by dry heat; lowering the temperature without reducing humidity produces a cold-humid environment that does not improve well-being.

2. Structural safety: if air humidity exceeds the critical threshold in contact with a cold surface, condensation forms on the floor, with the risk of slipperiness and mould.

Compatible dehumidification systems are dedicated dehumidifiers and controlled mechanical ventilation (CMV) with cooling function. The choice depends on the characteristics of the building and must be defined during the design phase.

Advantages of underfloor cooling

• Uniform thermal comfort: the temperature is distributed homogeneously over the entire surface of the room, without pockets of heat or excessively cold areas.

• Total silence: the absence of fans inside the rooms eliminates background noise, favouring night-time rest and concentration.

• Superior energy efficiency: the heat pump works with a reduced thermal delta compared to traditional split systems, reducing electricity consumption for the same comfort produced.

• Air quality: the absence of forced air eliminates the lifting of dust, pollen and mites, making the environment suitable also for those who suffer from allergies or asthma.

• Synergy with photovoltaic: cooling is more intense during the central hours of the day, the same hours in which a photovoltaic system produces the greatest amount of energy. The two systems integrate naturally, reducing operating costs during daytime hours.

Limits and constraints to consider

• High thermal inertia: the screed takes several hours to reach thermal regime. The system cannot be switched on and off as needed: it must be managed continuously throughout the summer season, with regulation entrusted to a smart thermoregulation system.

• Non-optional dehumidification: integration with a humidity control system is a technical requirement, not an accessory choice.

• Higher initial costs: compared to a traditional split system, the radiant system requires a higher initial investment, which includes the laying of pipes, the heat pump, dehumidification devices and smart regulation. Amortisation takes place over time thanks to lower seasonal consumption.

Better air conditioner or underfloor cooling?

The ideal solution? For those seeking excellence, integration is the key. Using a latest-generation heat pump air conditioner allows you to quickly manage sudden heat peaks or rapidly dehumidify the air after a shower, leaving the radiant system with the task of maintaining the “baseline” of domestic comfort.

How much does an underfloor cooling system cost?

The economic analysis must be honest: it is a premium system. The cost for laying the radiant system only (pipes, insulation, manifolds) varies between €70 and €110 per square metre. However, for a realistic “turnkey” calculation, it is necessary to consider:

1. Chiller / Heat Pump: a quality outdoor unit for an average home costs between €4,000 and €7,000.

2. Dehumidifiers: at least one or two modules are required (built-in or visible), with costs ranging from €1,200 to €2,500 overall.

3. Smart Regulation: temperature and humidity sensors in every room are essential to avoid condensation (approximately €500–1,000).

Despite the initial outlay, the system pays for itself thanks to savings on seasonal consumption and tax deductions: the 2026 Ecobonus provides for a 50% deduction for the main home and 36% for second homes. In addition, the average duration of an underfloor system exceeds 40 years, compared to 10–15 for a split.

Consumption Analysis: efficiency that is convenient

Why is the radiant system the best friend of saving? The answer lies in the COP (Coefficient of Performance). A heat pump that has to produce water at 18°C for the floor makes much less effort than one that has to produce it at 7°C for a split.

• Lower thermal delta: less effort for the compressor means fewer kWh consumed.
• Inertia as a thermal battery: once cold, the floor maintains the temperature for hours even when the system is switched off.
• Synergy with photovoltaic: since cooling is needed when there is sun, the energy produced by your panels can directly power the heat pump, bringing the cost of cooling to zero euros during daytime hours.

Frequently asked questions