How To Spec Your Grain Store
So now that you have chosen Polycool as your grain ventilation solution, how do you decide how many units you need to service your grain store?
The following formula provides a simple way to calculate this for you:
CEREALS
STORAGE DEPTH X 2 = THE DIAMETER OF THE CIRCLE WHICH EACH UNIT WILL VENTILATE
OSR
STORAGE DEPTH X 1.75 = THE DIAMETER OF THE CIRCLE WHICH EACH UNIT WILL VENTILATE
For example if your cereal crop is stored at 3m depth, then each pedestal will ventilate a 6m diameter circle. This means that the pedestals can be spaced 6m apart from each other and 3m from the side or back walls of the store. Uneven storage heights will need to be averaged out to obtain a representative depth across the store.
The chart below will allow you to calculate how many fans you will need for your Polycool grain ventilation pedestals based upon your intended storage depth.
Pedestal to Fan Ratios
| Storage Depth | % Example Moisture Content (Cereals) | Pedestal:Fan Ratio |
|---|---|---|
| 2.5-3.5M | 16 | 4:1 |
| 3.6-4.5M | 16 | 3:1 |
| 4.6-5.5M | 16 | 2:1 |
| 5.6M + | 16 | 1:1 |
As crop moisture content rises above the stated 16% the stored crop is much more prone to heating up quickly. Extra grain ventilation fans may be required in these situations.
