only 100,000 box capacity is built. In the east we pay in excess 

 of $5 per box. Are they tight? Most storage operators require 

 a pressure drop of 1 inch to no less than 0.75 inches water gauge 

 in 1 hour. They get it. Many of our CA rooms could meet that 

 requirement, but many are not that tight. 



CA equipment in most establishments is similar to ours. I 

 believe all rooms are equipped with a Tectrol-Samif i or a COB 

 oxygen burner. After the rapid O2 pulldown, CO^ scrubbing is 

 usually done with lime and/or a molecular sieve"scrubber . The 

 latter draws many kilowatts, which cost only l.l<f: along the dammed 

 Columbia River. Most operations still use an Orsat gas analyzer, 

 but a few are trying Teledyne or Beckman ©2 analyzers. Most 

 operators still rely on alcohol thermometers (Taylor 1106 or the 

 more easily read Taylor 5499), which are normally placed at the 

 CA door and at least 1 additional thermometer is placed adjacent 

 to the windows located behind the evaporators. These windows also 

 permit visual inspection of defrost. Many rooms are equipped 

 with breather bags to equalize pressure in the rooms. All rooms 

 have pressure relief valves to release excessive pressure or 

 vacuum in the rooms. Ammonia is the most common refrigerant, all 

 evaporators are dry coil, and most are defrosted with water. 

 Modulating back-pressure valves on the evaporators, which automat- 

 ically control the evaporator coil temperature according to the 

 heat removal requirement in the room, are common when ammonia is 

 the refrigerant. My recent survey study of eastern CA rooms 

 indicated higher relative humidity when these back-pressure control 

 valves are used. 



CA strategies are more diverse than ours. Four CA regimes 

 appeared to be in general use. (1) Normal CA. Rooms are filled 

 in 7 to 10 days, oxygen is lowered to 2% (if possible) in 3 to 

 7 days with 0^ burner. The room is maintained at 1.5 to 2.0% O^ 

 and below 1% CO^. If the 0^ cannot be held below 21, the CO^ is 

 raised to 2%. This regime is similar to ours except that we 

 do not recommend 0-^ concentrations below 2.0% (2) Rapid CA. The 

 room is filled and sealed in 3 days. Field heat removal requires 

 7 to 14 days. The 0^ is quickly burned to below 2% and held at 

 about II (if possible) for 1 week. For the remainder of the season 

 the O2 is held at 1.5 to 2.0% and the CO, below 1%. The short 

 delay between harvest and the time when 62 is below 2% results in 

 a substantial increase in firmness. We would consider this to be 

 a dangerous practice because our test results with Mcintosh 

 indicated rapid cooling is more important than rapid 0, pulldown. 

 We also would consider the 1% 0, for 1 week to be very risky. 

 This strategy is worthy of trial if apples are rapidly precooled 

 in adjacent rooms and assembled in 1 room for CA. Also, the 0^ 

 should be kept at 2.0 to 2.5%. (3) Low O2 CA. The room is 



