TY JOUR TI Approximate calculation of a theoretical cycle of a vapor-compression freon loop in an air heat pump KW vapor-compression cycle KW freon loop KW enthalpy KW air heat pump JO Smart composite in construction AU Fedosov, S.V. AU Fedoseev, V.N. AU Loginova, S.A. AU Zaitseva, I.A. PY 2021 IS 2 PB Yaroslavl State Technical University