Ten thousand pounds lard daily in four hours running would require the extraction of about two tons of duty, but by reason of the heat transmission and the low temperature brine necessary would require twelve tons duty while applied. Fifteen tons daily ice making capacity requires about 30 tons refrigerating duty, allowing for radiation and other losses. A freezer capacity of 100,000 cubic feet which would store 1,500,000 pounds would not appear excessive. From known results this would require about one ton refrigerating duty for 3,000 cubic feet of space or thirty-five tons machine duty. We have then: SUMMARY OF REFRIGERATION REQUIRED Tons 143,000 cubic feet beef cooler space ÷ 10,000 14.3 100 cattle daily 500 pounds = 50,000 pounds 50,000 pounds meat chilled 70° or 70 B.t.u. per pound 50,000 × 70 = 3,500,000 ÷ 288,000 B.t.u. 12.2 54,000 cubic feet hog cooler space ÷ 10,000 5.4 250 hogs 180 pounds each = 45,000 pounds 45,000 × 70 ÷ 288,000 = 10.9 200,000 feet cellar space ÷ 12,000 16.6 15 tons ice × 2 tons refrigerating duty 30.0 10,000 pounds lard cooler 12.0 100,000 cubic feet freezer space 35.0 ----- Total tonnage refrigerating effect 136.4 =Low Temperature Brine System.=--The use of low temperature brine, cooled by two stage compressors, a new development, is in the writer’s opinion preferable to direct expansion. (See description of two stage compression in Chapter IV.) A lineal foot of pipe filled with a liquid like chilled brine seems to have greater heat absorbing power than the same pipe filled with a light gas and consequently less piping can be used. _Preference Reasons._--Occasion arose to compare for a new large installation the relative merits of direct expansion versus brine and the following items suggested themselves: (1) The direct expansion plant would require 150,000 lbs. ammonia in excess of brine plant. (2) There would be approximately 8,000 more joints to prevent leaking. (3) Unavoidable ammonia leakage through rods, glands, valve stems, compressor rods and purging would amount to at least $20,000 per year based on experience with good practice. (4) The installation by the same manufacturer estimated to cost 15% more than a brine system. (5) There would be no stored energy in the ammonia pipes as in brine pipes should the refrigerating plant suspend operation temporarily. (6) The compressor hazard from returning liquid and possible machine wrecking with line breaks, ammonia losses, and danger to life. (7) In case of extension or modification of piping, the difficulty with ammonia pipes over brine is marked.