Let's analyze each option to determine which one correctly defines a ton of refrigeration.
1. Option a: 1 ton of ice
- This is not a direct measurement of refrigeration capacity. It is a weight measurement, not a rate of energy transfer.
2. Option b: [tex]$288,000 Btu / 24-hr$[/tex]
- A ton of refrigeration indeed equals 288,000 Btu (British thermal units) over a 24-hour period. This matches the standard conversion metric used in HVAC (Heating, Ventilation, and Air Conditioning). It is the correct definition reflecting the energy transfer rate over time that corresponds to melting one ton of ice within 24 hours.
3. Option c: [tex]$144 Btu / hr$[/tex]
- This is incorrect because it significantly underestimates the energy transfer rate for a ton of refrigeration. This value does not match the accepted definition.
4. Option d: [tex]$12,000 Btu / min$[/tex]
- This is again incorrect because it overestimates the energy transfer rate for a ton of refrigeration. The actual rate is not this high.
Therefore, the correct answer is:
Option b: [tex]$288,000 Btu / 24-hr$[/tex]
This matches the standard definition of a ton of refrigeration.