The air-conditioning system of an independent ventilation cage (IVC) often controls the cage-level and room-level environments. However

compared with the room-level macroenvironment

the surrounding environment of laboratory animals

known as the animal feeding microenvironment

plays a key role in improving their welfare. To optimize the control method of the feeding microenvironment and the performance of the IVC air-conditioning system

a heat transfer model was established and the IVC mouse feeding microenvironment was simulated using computational fluid dynamics models. The microenvironment and macroenvironment parameters were also measured experimentally. The results demonstrate differences between the IVC mouse feeding microenvironment and macroenvironment parameters. The air supply speed in the IVCs at different locations in the same cabinet ranged from 2.79 to 4.94 m/s

which changed the velocity field in the cage. At supply air speeds of 2.97 and 4.94 m/s

the average wind speed at the inlet side was 54.7% and 60.4% higher than that at the outlet side

respectively. When the air supply speed reached 4.94 m/s

the wind speed behind the mouse exceeded 0.3 m/s

which is beyond the specified limit. The velocity field also affected the temperature

humidity

and pollutant concentration distribution. These results demonstrate that the IVC air-conditioning system should be designed based on cages with the worst hydraulic balance to improve the feeding microenvironment and ensure the welfare and quality of laboratory animals.