The thermal system is a fixed technological system intended for winter or summer air conditioning services of environments, with or without production of domestic hot water, or intended solely for the production of domestic hot water, regardless of the energy vector used, including any systems for the production, distribution, storage and use of heat as well as the regulating and control organs, possibly combined with ventilation systems.
Systems dedicated exclusively to the production of domestic hot water for individual residential units and similar are not considered thermal systems.

Thermal systems are divided into:

• autonomous system: serving a single user
• centralized system: serving multiple users, such as in condominiums.

They are characterized, albeit with due differences, by some common elements.
They are both equipped with a heat generator (boiler) powered by a liquid or gaseous fuel; chimney for the evacuation outside of combustion products (fumes); a distribution system of the heat transfer fluid (water, air or steam) and terminals to provide individual rooms with the necessary thermal power to control the internal temperature (radiators or convectors).
Cooling systems are generally defined as air conditioning systems, while in the most common exception for thermal systems reference is made to the system dedicated to winter heating only.
A solution that is gaining ground in the field of indoor heating, better in terms of thermal performance and aesthetics but evidently more expensive, is radiant floor heating.In practice, an insulating layer is laid on the subfloor so that heat cannot be dispersed downwards, and a series of pipes with a flexible tube serpentine are placed on top of it. Subsequently, the built work is embedded in the screed of the coating (usually tiles).
The system has significant advantages over traditional systems, including improved living comfort: heat is transferred uniformly from the floor to every corner of the house. This can also serve as a summer cooling system with minimal modifications; obviously in the summer period cold water at 10°C will circulate. In this case, installation of a dehumidification system is required.