Indoor environmental quality and infection control in surgery rooms: Code requirements vs. performance motivation. A critical review

Surgery rooms are a space type with particularly stringent indoor environmental quality (IEQ) requirements (large airflow rates and narrow comfort windows), which translate into high energy use. Due to the unclear IEQ and infection control requirements for surgery rooms in Spain, these spaces are often designed and operated 24 hours per day and 7 days per week, to meet the most stringent recommendations (not only the requirements) in the available standards and guidelines. This paper critically reviews the Spanish mandatory requirements for surgery rooms by comparing them against their performance motivation and other international standards. Regulatory ambiguities and code-compliant energy efficiency opportunities are identified. The requirements and recommendations in the standards included in this review differ in their magnitude (particularly the airflow requirements), but are similar in their prescriptive nature. This paper identifies the performance goals associated to the prescriptive requirements, and proposes a method to adjust system operation (outdoor airflow rate, total supply air, indoor air temperature, and indoor air relative humidity) to meet IEQ performance goals while reducing energy use. Further work is required to define operation infection control requirements for the different surgery types and enable a performance based control strategy based on real time particle concentration monitoring.