One of the most important factors in the design of a new pharmaceutical or biotechnology manufacturing facility is frequently the design, installation, commissioning, and qualification of clean rooms heating, ventilation, and air conditioning (HVAC) systems. Getting them properly is crucial for business, safety, and good manufacturing practise (GMP) due to the high running costs (energy used for air movement, cooling, and heating) and potential impact on product quality and safety. The layout of the clean room suite, the number of rooms served, the equipment in the rooms, and—most importantly from the perspective of qualification—the climatic conditions that the rooms must achieve will all have an impact on the HVAC system's design. By delivering the right amount of clean air to each room at the right temperature and humidity, the air handling unit contributes to the maintenance of each space's clean environment. 

High efficiency particulate air (HEPA) filters are pleated paper filters that are used to filter the air. Depending on the kind of space, these filters may be found inside the air handling unit or at the point where the air enters each room. Additionally, cooling and heating coils are found inside the air handling unit, raising or lowering air temperature to maintain the desired room temperatures.

In addition to preventing a reduction in product quality due to inadequate air conditioning, reliable operation of the air handling unit within set limitations is essential for the following reasons:

• to prevent cross contamination of products
• to maintain operator safety, where the HVAC is being used for this purpose
• to maintain product safety, where the HVAC is being used for this purpose.