TY JOUR TI THE INFLUENCE OF REFRIGERANT ON THE PERFORMANCE CHARACTERISTICS OF AN AIR HEAT PUMP IN AIR HANDLING UNITS KW ventilation KW air handling units KW air heat pump KW refrigerant JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Petrov, M.M. PY 2026 IS 11 PB Belgorod State Technological University named after V.G. Shukhov