Altitude and air temperature make a substantial difference in the performance of any ventilation system. The calcuations I have provided here: http://mikeaurelius.wordpress.com/2007/12/25/ventilation-basics-part-two/ are based on sea level and 70 degrees F.
In the calculations, the only variable that needs modifying is VP, Velocity Pressure. The standard calculation is (V/4005) squared.
When applying temperature and altitude corrections, use the following equation: VP = ((V/1096.7) squared) times ‘density of the air in pounds per cubic foot’. Read the rest of this entry »
