Air treatment

Air treatment: dehumidification, cooling and MV

Air treatment refers to all the processes by which we ensure the air inside our home is clean and healthy, including controlling thermal conditions and air humidity, controlled air renewal and filtration systems for dust and other particles.

More and more often, hot-water radiant systems, designed to provide heating in winter, are also being used as air-conditioning systems in summer, with cold water. But to get the best out of a radiant system in summer we also need to control humidity to limit the risk of condensation on cold surfaces. Humidity can in fact be quite considerable in the home during summer. This can be the result of unfavourable external conditions and the presence of people, who contribute to increasing the water vapour through activities such as breathing, sweating and cooking. Another aspect is the perceived comfort of occupants. In accordance with that advised by UNI EN 7730, to ensure a sensation of comfort and keep indoor air healthy, relative humidity should not exceed 60-65%. For this simple reason, we recommend the installation of an air dehumidification system if a radiant system is used for cooling.


A dehumidifier is a device designed to lower the relative humidity of the air in a room, possibly mixed with air drawn from the outside, which is rich in oxygen and often contains less moisture than the air inside a house. There is usually a filter to purify the air before it enters the dehumidifying section of the device.

Dehumidification + air conditioning

In certain cases, an additional heat exchanger can be installed in the dehumidifier to cool the dehumidified air. This helps the radiant floor or ceiling system maintain the desired room temperature (approximately 26°C) if the summer heat load increases and along with this the demand for system cooling capacity. This type of device is known as a dehumidifying air conditioner.

Controlled mechanical ventilation

If the aim is to control the inflow of external air without having to open windows, the solution is a controlled mechanical ventilation system, or CVM for short, which can provide continuous single- or dual-flow air renewal.

In a single-flow system, external air enters following extraction of internal air. Flow can be constant or hygro-variable. In the first case, a constant air flow is continuously extracted from the service rooms of the house (bathrooms, kitchens, etc.) while external air enters via vents located on the external walls or windows. Alternatively, in the case of a hygro-variable flow, air is extracted from rooms according to the humidity of the room, which varies with the activity levels of the people within, while external air enters via special vents, possibly after being filtered.

In dual-flow systems the flow of oxygen-rich external air entering each room can be controlled by special vents or diffusers and an input fan. At the same time, pollutant-rich air is removed by a fan through special extraction outlets and expelled to the outside. The two air flows pass through a heat exchanger to limit energy loss to the outside.