The Fort Carson physical fitness facility consists of three main components: basketball courts, a natatorium and a fitness center. Each area has air-side systems capable of providing 100% outside air, while monitoring the return air CO2. This system enables the use of outdoor air for cooling when desirable, and the ability to reduce outside air when undesirable. RK Mechanical was responsible for the major mechanical equipment, including air handling units (AHUs), primary and secondary pumping systems for heating and cooling, high efficiency condensing hot water boilers and an air cooled chiller. RK Mechanical also incorporated a solar heating water system based on 30% of the domestic water heating load to further improve efficiency.