An analytical study was done to establish the energy consumption on two selected buildings located in two climatic zones utilizing rooftop mu1ti-zone units. The study analyzed the electro-mechanical controls versus solid state controls on draw-through reheat equipment and on blow-through equipment.

One of the buildings selected was a 33,000 square foot one story office building with 40% glass area and requiring 27% outdoor air for minimum ventilation. The building load was 100 tons divided into two 50 ton multi-zone units.

The second building was a 172,400 square foot two story retail store with 1.7% glass area and 10% outdoor air for ventilation. The building load was 560 tons divided into eight 70 ton units.

The two buildings were simulated to be located in Atlanta, Georgia and Chicago, Illinois and subjected to the 1957 weather bureau computerized weather data. Total loads for individual zones were established and projected against an algorithm for each unit and each control reference to establish the hourly building energy consumption.