How is the “SEER” calculated for air conditioners and sinilar equipment?
SEER or Seasonal energy efficiency ratio is a calculation of how much energy your unit will consume and not just the EER Air conditioner sizes are often given as “tons” of cooling where 1 ton of cooling is defined as being equivalent to 12,000 BTU/h. The annual cost of electric power consumed by a 72,000 BTU/h (6 ton) air conditioning unit operating for 1000 hours per year with a SEER rating of 10 and a power cost of 12¢ per kilowatt-hour (kW·h) may be calculated as follows: unit size, BTU/h × hours per year, h × energy cost, $/kW·h ÷ SEER, BTU/W·h ÷ 1000 W/kW this would be a 10 SEER Example: (72,000 BTU/h) × (1000 h) × (12¢/kW·h) ÷ (10 BTU/W·h) ÷ (1000 W/kW) = $864 annual cost As another example, a 2,000 sq ft (190 m2) residential unit near Chicago would require a 4 ton air conditioner based on a location-specific rule-of-thumb that 1 ton is required for each 500 sq ft (46 m2) for a typical older house: (2,000 sq ft (190 m2)) ÷ (500 sq ft (46 m2)/ton) = 4 tons. (4 tons) × (12,000 BTU/
