The purpose of this Information Report is to establish minimum performance levels in the operator's environment for heated, ventilated, and air- conditioned construction and industrial equipment cabs. Also established are heating and air-conditioning test procedures for determining operator environment temperature, humidity, and pressurization. Note: The subject of noise is not treated in this information Report. This Information Report establishes the minimum performance levels in the operator's environment: Minimum cab pressurization and ventilation levels under all conditions of heating, air conditioning, and ventilation. Maximum humidity and minimum temperature differential under air conditioning operation. minimum temperature differential under heater operation. The report also establishes uniform test procedures for determining minimum performance levels, as defined under 2.1.1- 2.1.3, under Heater and Air conditioner operation.