What is a Positive Pressure Operating Room? Structure of Positive Pressure Operating Room
Operating rooms are divided into many types, and depending on their intended use, clean rooms are designed and constructed as positive pressure rooms or negative pressure rooms. So what is a positive pressure operating room? What is the structure of a positive pressure operating room? Let’s find out through the following article:
What is a positive pressure operating room?
A positive pressure operating room (or positive pressure OR) is a specialized room designed to maintain a higher pressure inside the room compared to the atmospheric pressure outside the room. This is in complete contrast to negative pressure rooms. For example, if the pressure outside the room is 0, the pressure inside the room will be higher than 0, typically ranging from 5 to 45 Pascals (Pa).

Structure of positive pressure operating room
A positive pressure operating room consists of three main components: UV sterilization equipment, positive pressure generating equipment, and HEPA filter system.
UV Sterilization Equipment
For optimal sterilization effectiveness, air from outside, after undergoing primary filtration, is treated with UV rays before passing through HEPA filters. This process eliminates all dust particles, bacteria, viruses, etc.
Positive Pressure Generating Equipment
This equipment is essential for creating a higher pressure inside the room compared to the surrounding environment. Its function is to maintain positive pressure within the room, preventing dust particles, microorganisms, and molds from the outside environment from infiltrating into the room. Additionally, when multiple personnel are working in the room, the positive pressure generator provides sufficient oxygen for the room.

HEPA Filter System
The HEPA filter system is designed with zigzag-shaped filter layers, with a height of 80-100mm. To prevent filter collapse, the paper pleats have insulating material inserts. The filter can withstand high pressure to ensure an adequate supply of clean air for the room.

Operating principle of positive pressure operating room
The air filtration system will draw air from the outside, pass it through a primary filter to remove large dust particles and microorganisms. Then, the air stream will be sterilized by UV rays to kill bacteria before passing through the HEPA filter membrane, using a positive pressure generating device with strong pressure to completely remove contaminants.
Each room typically has an overhead air handling system. The sterile air supply system delivers clean air into the room, while the filtration and sterilization system removes pathogens in the air before discharging it into the environment to prevent the spread of diseases.
What is the operating principle of the positive pressure room air filtration system? First, the air filtration system of the positive pressure room will take air from the outside and pass it through a primary filter to remove large dust particles or microorganisms. The air stream will then be treated with UV rays to kill bacteria.
Next, the positive pressure generating device will draw and push the air stream through a high-efficiency HEPA filter with high pressure to completely remove adverse factors. Each positive pressure room typically has two air handling systems placed overhead. The sterile air supply system delivers clean air into the room. This is the purpose of a positive pressure room.
The air in the positive pressure operating room, before being discharged outside, will be reprocessed through a secondary filter. Then, it will be sterilized by UV rays to prevent contamination or spread of pathogens into the environment.

Factors affecting the effectiveness of positive pressure operating rooms
Always choose an air filtration system that meets the cleanliness requirements of the room. Use HEPA filters to achieve the highest efficiency.
Ensure that the air flow in the room changes continuously within an hour according to regulations to maintain cleanliness.
Use automatic sliding doors to avoid affecting the pressure difference in the clean room.
Regularly inspect and maintain air handling and fan systems to ensure they operate optimally.
Control and manage pressure in the room regularly.
To ensure cleanliness and safety for personnel in the room, dressing rooms, protective equipment supply areas, and medical equipment and supplies should be built outside the room, separated from the positive pressure operating room.
Standards to ensure in the design and construction of positive pressure operating rooms
MICROBIAL STANDARD:
WHO – Grade B (≤ 10 CFU)
WHO – High Level of Grade C (≤ 50 CFU)
DUST STANDARD:
Class 1,000 (0.5µm dust ≤ 1,000/f³ # 35,200/m³)
Class 5,000 (0.5µm dust ≤ 5,000/f³ # 176,000/m³)
Class 10,000 (0.5µm dust ≤ 10,000/f³ # 352,000/m³)
POSITIVE PRESSURE STANDARD: ≥ + 7 Pa; ≤ -2.5 Pa (CDC-USA)
AIR EXCHANGE RATE: ACH ≥ 15 (52TCN-CTYT 38:2005)
ENVIRONMENTAL STANDARD: Temperature ≤ 24°C; Humidity ≤ 60%; CO2 < 1,000ppm
Above are detailed information about positive pressure operating rooms. This type of operating room has a complex structure, so it requires professional design and construction units with experience to optimize and synchronize while providing reasonable solutions and construction methods, saving costs for hospitals and medical facilities.
INTECH Group is confident as a provider of consulting, designing, and constructing clean rooms and operating rooms for hospitals with the best quality of service, offering a reasonable solution for constructing positive pressure operating rooms, saving costs for hospitals and medical facilities.
Contact INTECH Group now to receive the earliest support from our experienced experts!





