The significance of infiltration air is seen in the assertion of a 1982 ASHRAE Work Statement ("A Study To Develop A Method Of Predicting Energy Losses Due To Infiltration In Refrigerated Warehouses". ASHRAE Research Project 362-RP. Final Report May 1988.) that nationwide, infiltration represents 50% or more of the refrigeration load of refrigerated distribution and storage facilities.

Since the rate of refrigeration loss through open doorways is extreme, and since the other problems of open doorways can be similarly extreme, a good estimate of percent of Door Open Time is essential to the selection of protective devices for these doorways. Therefore, because traffic intensity bears directly upon Door Open Time, a good understanding of the following doorway usage factors is required.

• Normal high traffic doorway
• Very high traffic doorway
• High production periods
• Low production periods
• Forklift speeds
• Tailing of vehicles
• One-way traffic
• Two-way traffic
• Nearby staging
• Cross docking
• Visibility concerns
• Number of pass-thrus for the work shift
• Seconds Per Pass-thru (to be used for doorway opening device selection)
• Other doorway congestion where immediate turning is required

Countering The Physical Forces
Unlike all other doorway products on the market today, the HCR product line was carefully developed and based on recognized engineering principles, with attention toward the scientific principles of applied psychrometrics and strictly observing the limits of the super-saturation curve of the USDA in all of its products.