A natatorium is an enclosed indoor swimming facility designed with specialized architectural and mechanical systems to manage humidity, temperature, and air quality created by water evaporation and human activity. The term encompasses competitive pools, recreational facilities, and therapeutic water environments. Natatoriums require sophisticated HVAC design to prevent moisture-related building damage and maintain safe, comfortable conditions.
Design Characteristics
Natatoriums typically feature pool water maintained at 78°F to 82°F, with air temperatures 1°F to 2°F above water temperature to minimize evaporation. Indoor relative humidity targets of 40 to 60 percent prevent condensation on windows and structural elements. Evaporation rates vary from 0.5 to 5 gallons per hour per 100 square feet of water surface depending on water temperature, air humidity, and ventilation.
HVAC System Requirements
Facilities require 100 to 150 percent outdoor air changes per hour, heat recovery ventilation, dedicated dehumidification, and chemical-resistant ductwork and materials. Building envelopes need vapor barriers and insulation rated R-15 to R-30 to prevent condensation and thermal losses.
Operational Considerations
Natatoriums demand continuous monitoring and balancing of humidity, temperature, and ventilation. Annual operational costs for medium-sized facilities range from 40,000 to 100,000 dollars. Chlorine, bromine, and saltwater chemistry require corrosion-resistant equipment materials including stainless steel, aluminum, and vinyl-lined components.