Norms

UNI 11425


Ventilation and air-conditioning system with controlled contamination (VCCC) for surgery unit


Design, installation, start-up, qualification, management and maintenance.

The standard provides directions for the design, installation, start-up, performance control, acceptance, management of systems and components that contribute to controlling contamination in the facilities and maintaining pre-set temperature and humidity conditions in units specifically intended to carry out surgery, called surgery units. The standard is applied to new systems and refurbishments concerning buildings and/or systems in surgery units and provides the minimum requirements to verify the conditions of use of existing ones.

Below are the values recommended by UNI 11425 for environmental parameters and some quantities associated with them.

To reach the designed air purity class in the various rooms, the standard also identifies the minimum efficiency level for the air filters:

(1) The pressure in operating theatres used for infected patient is lower compared to adjacent rooms
(2) Please refer to the examples in annex D
(3) In the event of renovation works where it is necessary to create class IOS5 operating theatres using room recirculation systems, the max noise level that can be reached is 48 dB(A9) and the project must contain the reason for the decision
(4) Depending on how clean the air needs to be, as well as the monitoring
(5) Minimum value if there are no other values that, set in relation to the specific crowding needs, sources of pollutants and based on a risk analysis