Intermittent air supply and return system for experimental animal environment facility

The utility model discloses an experimental animal environment facility intermittent air supply and return system which comprises a fresh air pipe, an air inlet is formed in the left end of the fresh air pipe, and a filtering assembly is arranged at the upper end of the air inlet. By the adoption of the structure, when the indoor and outdoor temperature difference is large, the first check valve closes the air inlet or controls the air inlet amount, the second check valve closes the air outlet or controls the air outlet amount, external air is prevented from entering the exhaust pipe through the air outlet to affect air return, the third check valve does not close the connecting position of the air return chamber and the second flow equalizing section any more, and the air return efficiency is improved. The third air feeder section can extract indoor air through the air return opening, the extracted indoor air is purified through the activated carbon filter and the second efficient filtering section, the indo