For those of us in the construction industry, our obligation as stewards of creation is to design sustainable and energy-efficient buildings. Designing health care facilities can be a special challenge because of the amount of energy needed to maintain a sterile and safe environment for patient care. Traditional systems that simultaneously cool and reheat air for dehumidification purposes are generally the greatest source of energy waste in health care facilities. Rethinking the way we design hospitals can immediately achieve 30% to 50% energy use intensity (EUI). Our goal is to find energy savings for dehumidification while maintaining a clean atmosphere for quality health care as regulated by department of health service codes.
What primarily drives dehumidification in hospitals are the individual room requirements for outside air change rates, room exhaust, and pressurization for the purpose of infection control. Nursing and ancillary (mainly laboratories and radiology) inhabit most of the square footage of the hospital and call for two ach of continual outdoor air. Surgical and critical-care rooms can require up to four ach of outside air supply, and airborne infection isolation, emergency waiting, triage, and various rooms in the laboratories and pharmacy will need eight to 15 ach of exhaust. Outdoor air is mandatory to make up the volume of air being removed from these rooms, and additional air must be brought into the building to protect the areas with higher sterility requirements. Hospital codes require air movement to travel from clean to the less clean areas.