The general rule for rating refrigeration systems (excepting for CO₂ system) is to approximate following h.p. per ton of refrigeration

A. 0.1 to 0.5 h.p. per ton of refrigeration

B. 0.5 to 0.8 h.p. per ton of refrigeration

C. 1 to 2 h.p. per ton of refrigeration

D. 2 to 5 h.p. per ton of refrigeration