In order to research into disturbance of constant temperature laboratory such as equipment heat radiation fluctuation,blast airflow fluctuation and infiltration air effect on the temperature stability of the room,the CFD simulation method is applied to analyse the temperature dynamic response characteristics with disturbance function.

However,disturbances from inside and outside of the constant temperature room,such as infiltration air,the equipment radiation fluctuation will affect the temperature stability.

This paper states the present calculation methods of ventilation and infiltration airflow in large spacebuiding Points out that the sticking point of calculating airflow is the confirmation of wind pressure coefficient andheat pressure coefficient and the neutral plane position.

Based on the calculation methods of integrated correction factors of cold air infiltration offered by "Code for HVAC design specifications", "Heating supply engineering"and "Practical heating and air conditioning design manual , edited a calculating program.

Calculation of heating load of highrise buildings due to air infiltration;

Reducing air infiltration in a high-rise building by increasing interior separations;

Based on the test and analysis of a passive solar house in Qinghai,the calculating method which air infiltration affect heating and temperature of the passive solar house was identified,and the effect of heating and saving energy is better.

Obtains a new comprehensive correction coefficient after calculating the infiltration rate per meter gap of doors and windows and per unit time.

Analyses the determination of surface heat transfer coefficient, interior building envelope load, air infiltration load, equipment load and heat storage load, etc.