Temperature and humidity requirements are important in hospitals,Proper air conditioning is helpful in the prevention and treatment of disease, the application of air conditioning to health facilities presents many problems not encountered in the usual comfort conditioning design.

The basic differences between air conditioning for hospitals (and related health facilities) and that for other building types stem from

(1) the need to restrict air movement in and between the various departments;

(2) the specific requirements for ventilation and filtration to dilute and remove contamination in the form of odor, airborne microorganisms and viruses, and hazardous chemical and radioactive substances;

(3) the different temperature and humidity requirements for various areas; and

(4) the design sophistication
needed to permit accurate control of environmental conditions.

Design of an Operating Theatre

HVAC system design for an operating theatre starts with a reminder of the following key objectives:
- To control the concentration of harmful bacteria;
- To prevent infiltration of less clean air into the operating theatre;
- To create an air flow pattern that carries contaminated air away from the operating table;
- To provide a comfortable environment for the patient and operating team;
- To ensure uninterrupted operations;
- To save energy.

The operating theatres are categorised as 'general' and 'ultraclean'. Ultra-clean OTs, used for procedures, such as, organ transplant, orthopaedic surgery, neurosurgery, etc., where bacterial contamination is relatively more critical.