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.
One Ton of Cooling is equal to 12,000 BTU/h. A condenser unit that can continuously cool at 12,000 BTU per hour has a 1 ton capacity. According to Dr-Fix-It, the name comes from the fact that it takes 288,000 BTU to melt one ton of ice at 32 Â°F to water at 32 Â°F in 24 hours, which is 12,000 BTU per hour.