1 The freezer time shown is for best quality only â foods kept constantly frozen at 0Â° F will keep safe indefinitely.  How long does baked ham last at room temperature? Bacteria grow rapidly at temperatures between 40 Â°F and 140 Â°F; baked ham should be discarded if left for more than 2 hours at room temperature.
Using this to calculate theoretical water-chilling capacity: 1 ton of refrigeration (12,000 BTUs per hour) will chill. 12,000 lbs. water/fish 1Â°F in 1 hour. Theoretically, then, a sample application to chill seawater and fish: 40 tons refrigeration (480,000 BTUs per hour) will chill. 120,000 lbs. water/fish 20Â°F in 5 hours.
It is defined as the heat of fusion absorbed by melting 1 short ton (2,000 lb; 0.893 long tons; 0.907 t) of pure ice at 0 Â°C (32 Â°F) in 24 hours. It is equivalent to the consumption of one ton of ice per day and originated during the transition from stored natural ice to mechanical refrigeration. A refrigeration ton is approximately equivalent to 12,000 BTU/h or 3.5 kW. Air-conditioning and refrigeration equipment capacity in the U.S. is often specified in tons (of refrigeration). Many manufacturers also specify capacity in BTU/h, especially when specifying the performance of smaller equipment. British thermal unit.