The goal of the air distribution inside a hospital operating room (OR) is to protect the patient and staff from cross-infection while maintaining occupant comfort and not affecting the facilitation of surgical tasks. In ORs, HEPA-filtered air and vertical (downward) laminar airflow are often used to achieve a unidirectional flow of fresh air from ceiling, washing over the patient and flowing out of exhaust vents on the side walls, near the floor. However, previous research has shown that this method does not necessarily achieve the desired unidirectional flow pattern or adequately achieve optimal air asepsis. The results from this study show that maximizing the area of the laminar flow diffusers remedies this issue and provides very low contamination levels. The use of air curtains as specified by manufacturers of commercial products may not provide satisfactory results, with noticeable contamination levels at the wound site.