This paper examines a Good Laboratory Practice vivarium, and introduces a design for a cooling and heating source for air conditioning, a ventilation system, airflow distribution and an automatic control system. Through Computational Fluid Dynamics(CFD)simulation technology, the airflow distribution of the vivarium was optimized, and the result show that a ceiling air supply and corner exhaust with auxiliary top exhausts could help to reduce the indoor ammonia concentration. The demand-based variable air volume control mode of the vivarium is highlighted, reflecting the energy savings of the control mode. Finally, future concerns of HVAC design in vivariums are presented.