With 25 years of mostly bad experience in shopping center air conditioning, it is now possible to make a definite statement regarding the appropriate system to satisfy the requirements of those concerned.

The interests of the proprietor, large retail operators, and small retailers are served by an installation with low capital cost, low operating costs, reliability, and good performance. A consulting engineer given this brief would have to follow quite well-defined parameters to arrive at the correct solution. The following are considered to be the most important:

1. Multiple self-contained units to serve the specialty shops and malls with individual control in each shop.
2. Multiple self-contained units to serve the larger retail areas.
3. Central system with heat recovery from display case refrigeration to serve the supermarket.
4. Refrigeration with air-cooled condensing units with multiple reciprocating compressors and direct expansion cooling units.
5. The use of up to 100% outside air under automatic control in all air units except in the supermarket.
6. The use of high capacity filters.
7. The use of adjustable-pitch axial flow fans.
8. Medium velocity, low pressure air-distribution system.

Units: Dual