As the example of construction machinery, different heating resources and heat transferring loss of the cabin body are studied by the conditions of engine pre-started 、 pre-heating the air and keeping its temperature in cabin. 分别对工程机械的发动机进行预热启动和加热,并在保持驾驶室环境温度情况下,研究了不同热量来源和传热损失的影响;