Clean air heat pump (CAHP) is a new technology that combines air cleaning with hygro-thermal control of ventilation air. In CAHP, a regenerative desiccant wheel is used for moisture control and air cleaning. This study investigated experimentally the air cleaning performance of CAHP system for ammonia removal. The results showed that, as opposed to the operating parameters of CAHP system for Volatile Organic Compounds (VOCs) removal, ammonia could not be continuously removed when the wheel was regenerated by low-temperature thermal energy. A higher regeneration temperature, possibly more than 90C, was required. In this case, the single-pass air cleaning efficiency for ammonia reached 86.5% when the concentration was 2.5 ppm. When the concentration of ammonia was increased to 7.1 ppm, the air cleaning efficiency was still maintained above 67%.