Calculators › HVAC and building envelope Usable recovered condenser heat calculator
Usable recovered condenser heat
Useful recovered condenser heat rate is calculated as (q_cooling + 3412 × P_compressor) × f_recover. Use the stated system boundary and matching input units.
Units IP (US) SI (metric)
q use = ( q cooling + 3412 × P compressor ) × f recover q_{\text{use}} = \left(q_{\text{cooling}} + 3412 \times P_{\text{compressor}}\right) \times f_{\text{recover}} q use = ( q cooling + 3412 × P compressor ) × f recover q use = ( q cooling + P compressor ) × f recover q_{\text{use}} = \left(q_{\text{cooling}} + P_{\text{compressor}}\right) \times f_{\text{recover}} q use = ( q cooling + P compressor ) × f recover
Calculator
Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.
Worked example
Given
q cooling q_{\text{cooling}} q cooling 100 Btu/h P compressor P_{\text{compressor}} P compressor 50 kW f recover f_{\text{recover}} f recover 0.8 — q use = ( 100 + 3412 × 50 ) × 0.8 = 136 , 560 q_{\text{use}} = \left(100 + 3412 \times 50\right) \times 0.8 = 136{,}560 q use = ( 100 + 3412 × 50 ) × 0.8 = 136 , 560
Given
q cooling q_{\text{cooling}} q cooling 80 kW P compressor P_{\text{compressor}} P compressor 18 kW f recover f_{\text{recover}} f recover 0.7 — q use = ( 80 + 18 ) × 0.7 = 68.6 q_{\text{use}} = \left(80 + 18\right) \times 0.7 = 68.6 q use = ( 80 + 18 ) × 0.7 = 68.6
Symbols and units
Symbol Meaning Unit
q use q_{\text{use}} q use useful recovered condenser heat rate Btu/h q cooling q_{\text{cooling}} q cooling evaporator cooling rate Btu/h P compressor P_{\text{compressor}} P compressor compressor electrical input kW f recover f_{\text{recover}} f recover usable fraction of condenser heat —
Symbol Meaning Unit
q use q_{\text{use}} q use useful recovered condenser heat rate kW q cooling q_{\text{cooling}} q cooling evaporator cooling rate kW P compressor P_{\text{compressor}} P compressor compressor electrical input kW f recover f_{\text{recover}} f recover usable fraction of condenser heat —
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