Airserco Refrigeration Calculator, Hermetic Motor Connections
Refrigeration Calculator Guide to Back and Head Pressure

This tool is a guide to calculating back and head pressures on refrigeration systems that use R12, R134a, R22, R123, R404a, R407c, R410a, R507, and R508b refrigerants.

On the front of the guide is a sliding chart to calculate back pressure, air temperature and head pressure for specific suction temperatures and condenser temperatures. This guide is simple to use and takes the guess work out of checking proper charge of a system.

On the back side is a color chart for start, run and common wires on specific models of compressors. Also on the back is a thermostat control setting chart for different types of equipment and a guide for evaporator temperatures. This item is made of thick cardboard stock with metal corner rivets and is 7.25 inches long by 3.5 inches wide.