During the 1930s and 1940s, natural gas engine-driven cooling systems dominated the U.S. market. In the 1950s and 1960s electric
equipment began competing with natural gas equipment due to increased electric chiller efficiencies and the growing electric utility infrastructure.

Engine-driven chillers still were successfully marketed by the gas utilities and manufacturers in the 1960s. The gas companies used
promotional rates and subsidies programs to entice buyers. The outstanding operating economics were sufficient to place nearly 2,000
units in the field between 1962 and 1970. The majority of these were located in Texas, presumably due to higher cooling loads and the
availability of cheap gas. Counteracting this, innovations in compressors, electric motors, and controls increased the performance and
decreased the cost of electric cooling systems.

In the 1970s, price controls and other government restrictions helped push electric chiller sales ahead of gas chillers. The gas crunch
of the seventies curtailed gas cooling promotion and forced prospective buyers to select conventional electric systems.

There are few Commercial applications of Engine chillers or Engine Driven Cooling currently in use in the Industry today. One of the
main applications nearest to this technology is Transport Refrigeration. This technology uses primarily Diesel Powered Engines to
drive the compressor.

The most predominant equipment I ever saw in west Texas, was the Redi-Power System. The system was comprised of an International Harvester, natural gas fired six-cylinder engine, coupled to an open drive compressor. It was a D/X system with a water cooled condenser.
In addition to serving the condenser for the refrigeration system, the cooling tower also provided the cooling for the engine. On a demand for cooling, the solenoid valve would open, suction pressure would rise, make a low pressure switch, which was connected to the ignition control panel of the engine and a control relay would signal the condenser water pump. Once the engine started, it would get on the governor, the compressor would load-up and we had cooling. When the thermostat satisfied, the solenoid would drop out causing the compressor to un-load and pump down. When the suction pressure hit the cut-out set point, the engine was shut down. Seconds later the condenser water pump would cycle off. It had a relatively elaborate “for that time” control box for the starter on the engine and the ignition circuit.

This system was installed in the early 60s’. The exhaust system ran straight up thru the ceiling, and up to the roof, where the muffler for the
engine was mounted on the roofs peak, and high above the ground.
When you got a call for no cooling, you did not know if you were going to tune up the engine, or troubleshoot a refrigeration problem.