How this calculator works
The air-cooled condenser designer calculates required condenser capacity (kW) and selects an appropriate unit from Izhar's equipment library using the Total Heat of Rejection (THR) method from ASHRAE Refrigeration Handbook 2022, Chapter 35. THR = refrigerating capacity × (1 + 1/COP), adjusted for compressor heat of compression at the specified saturated discharge temperature (SDT). Pakistan-specific ambient derate is applied: medium-temperature systems lose 2.0 %/K above the ASHRAE reference ambient of 35 °C; low-temperature systems lose 2.7 %/K. A hard floor of 60 % rated capacity is applied regardless of ambient (below 60 % the unit is undersized even with all oversizing headroom consumed). The tool warns when saturated condensing temperature (SCT) ≥ 55 °C — above this threshold Bitzer compressor warranty may be voided and oil carryover risk increases. Validated against Bitzer Software 6.x and Heatcraft NROES unit selection for Pakistan summer conditions.
References: ASHRAE Refrigeration Handbook 2022 Ch. 35; Bitzer Refrigerants Report 25 (2022); Heatcraft Refrigeration Product Selection Guide.