Air Loss in Chimneys

The efficiency of the appliance, its on/off ratio and the insulating qualities of the stack will determine the temperature of the gases in the chimney. The on/off ratio will determine the flow. The fuel will determine the gases' composition. The diameter, or equivalent diameter in the case of a rectangular cross section, and the roughness will determine the velocity. The temperature will determine the buoyancy. Local air pressure will have an influence, as will local weather conditions...

Er, why calculate it; what would be the meaning of the calculation?

Air flow can be measured with a suitable instrument.

I have to prove that the designed heating system ( opened chamber gas heater) instaled in the kitchen, is a source of air loss due to the permanent openings we have ; chemney and air inlet. Apart of the positive effect of natural ventilation, appears the disconfort caused by the cold air and it's movement.

For what reason?

To calculate an amount of the airflow you need to know:

1. Temperature of outside air in intake and temperature of exhausted air.

2. Area of inlet and outlet

2. Difference in the elevation.

Then you can calculate it on principle of natural ventilation.

If you do not know how to do it, please find it through Google

thank you,

I will try once more to find one site by google search