Fans for wood drying kiln

Fans for wood drying kiln.
Then you define parameters for the fans. For example, select fans for wood drying kiln in the figure.
Basic parameters: performance, pressure, engine power, engine speed, price.
  At a price more favorable fans with larger blades as the fan performance is directly proportional to the area to cover the blades. Thus, the performance of the fan with a blades diameter of 80 cm may be 1.8 times more than that of the fan with a blades diameter of 60 cm (8×8=64; 6×6=36; 64/36=1.8 ).
  We have the wood drying kiln with the stacking width 2.0 m and the stacking length 6.0 m, so we have to use at least two fans for uniformity of the air flow. Then we calculate the necessary performance fans. Stacking length 6.0 m, stacking height 2.5 m.
We get cross-sectional area of the lumber stacking 6 × 2.5 = 15 m ².
We take a board thickness 20 mm and a thickness of kiln sticks 20 mm.
We get cross-sectional area for airflow 15/2 = 7.5 m ².
Choose the air velocity 1.5 m / s.
We get performance fans 7.5m ² × 1.5 m / s = 11.25m ³ / s or 11.25m ³ / s × 3600 = 40500 m ³ / hour.
  Sales have fans for wood drying kilns with a blades diameter of 60 cm and parameters:
  - performance - (10 000 – 16 000) m ³ / h,
  - pressure - (200 - 350) Pa,
  - engine power - 1.5 kW,
  - engine speed - 1480 rev / min.
We can buy three such fans for drying kiln, asking the manufacturer to replace the motors 1.5 kW to 1.1 kW, since the stacking width is 2.0 m and high pressure is not needed.

Now to the height of the second ceiling you add the overall size of the fan and get the ceiling height of your kiln.