gravity flow evaporative cooling tower?

Question

There is a formula, to calculate duct or shaft size and shaft height.You can place the right sized evap. downdraft cooler on top of the right size and height tower and cool air flows down the shaft without a blower. All you add is water to the pads. Anyone know the formula? Thanks!.......Larry

Answer 1

any cooling at all will cause air to move down the shaft, the cooler the air column, the faster it will begin to flow.

If you know the change in air temp then you can use V1/V2=T1/T2, to calculate the air density change.

You can the use H*d*G to calcualte the boyant force in the shaft. This force will be equivalent to the pressure rating of the blower you would now not require.

To get the speed the air goes in the column, you need the formual for friction in a duct, I don't have that.