Operating Theater Ventilation: Designing Cleanrooms According to DBN Standards

Ventilation in an operating block is more than just comfortable temperature; it is primarily a barrier against healthcare-associated infections. Designing "cleanrooms" is the most high-tech stage of medical engineering, where every cubic meter of air must be sterile.

Key System Requirements

The engineer's main task when designing an operating room is to create an environment where the concentration of microorganisms and dust particles is minimized. According to DBN V.2.2-10:2022, this is achieved through:

1. Multi-stage Filtration: Air passes through a series of filters, the last of which is a HEPA filter (H13 or H14 class), trapping 99.9% of particles.

2. Laminar Sterile Flows: Air is supplied vertically directly over the operating table, creating a "piston" effect that pushes contaminants toward exhaust vents.

3. Positive Pressure: Pressure in the clean zone is always higher than in the corridor, ensuring that when doors open, air flows out rather than pulling bacteria in.

Comfort and Technology

Beyond purity, the system must maintain a constant temperature (usually 18–22°C) and humidity, which are critical for medical equipment and the patient's state under anesthesia. Modern designs also incorporate energy efficiency — using recuperators that recover heat without mixing exhausted and supply airflows.