Final answer:
One ton of refrigeration equals 288,000 BTU/day, 12,000 BTU/hour, 200 BTU/minute, and 3.333 BTU/second. The energy efficiency rating (EER) indicates the heat transfer in BTUs per hour per watt of power input. The cost of running a 4-ton air conditioner with an EER of 12.0 can be calculated based on the energy consumed and local electricity rates.
Step-by-step explanation:
A ton of refrigeration is defined as the amount of heat removed to freeze a short ton (2000 pounds) of water at 32°F in 24 hours. Based on the standard measurement, 1 ton of refrigeration equals 12,000 BTU per hour. To convert this to other time bases, you can use the following conversions:
- 12,000 BTU/hour
- 288,000 BTU/day (24 hours * 12,000 BTU/hour)
- 200 BTU/minute (12,000 BTU/hour / 60 minutes)
- 3.333 BTU/second (12,000 BTU/hour / 3600 seconds)
When discussing the energy efficiency rating (EER) of air conditioners, it is the number of BTUs of heat transfer from a cold environment per hour divided by the power input in watts. A 4-ton air conditioner with an EER of 12.0 is considered to have good efficiency, as it removes 48,000 BTUs per hour and would require 4 kW (48,000 BTUs / 12 EER = 4,000 Watts) of power input. Converting BTUs to Joules, 48,000 BTU/hour is equivalent to 5.06×107 J/hour.
If the cost of work is 10 cents per kilowatt-hour, you would calculate the cost by dividing the energy input in Joules by the cost per Joule (since one kilowatt-hour is 3.60×106 J). If the air conditioner operates for 1 hour, the cost would be 10 cents for each 3.60×106 J consumed. The actual cost effectiveness depends on local electricity rates and usage patterns but can be assessed for realism based on these factors.