Grain storage, Fan operation, Equilibrium moisture chart – Grain Systems PNEG-010 User Manual
Page 19
6. Fan Operation
PNEG-010 Vane Axial Fan
19
Grain Storage
IMPORTANT: Conditions and requirements may vary from area to area. Contact the local agriculture
extension office or state agriculture university for more exact guidelines.
Average grain temperature should be above 35°F in the winter and below 65°F in the summer. Always try
to keep the grain within 10°F-15°F of the average monthly outside temperature. This means grain may
need to be aerated on warm days during the winter to stay above 35°F when freezing temperatures are
predominate. During the summer it may be necessary to aerate the grain on cool nights, so the 65°F
temperature is not exceeded during the hot days of summer.
If the grain is to be stored more than 1 year, it has to be recooled the following fall and winter, repeating
the process as long as the grain is in storage. Frequent and regular inspection (at least weekly during
fall and spring) is the best prevention against grain spoilage.
Equilibrium Moisture Chart
Approximate Allowable Holding Time for Field-Shelled Corn, to Maintain Grade*
Air
Temperature
Percentage Relative Humidity
35
40
45
50
55
60
65
70
75
80
85
90
95
100
20°F
11.2
11.7
12.7
13.7
14.5
15.1
16.2
17.1
18.0
19.6
21.2
23.5
25.8
29.1
30°F
10.8
11.3
12.2
13.1
13.9
14.6
15.5
16.4
17.4
18.7
20.2
22.5
25.0
28.3
40°F
10.5
11.0
11.7
12.5
13.3
14.0
14.8
15.5
16.6
17.8
19.4
21.5
24.2
27.5
50°F
10.1
10.6
11.3
12.0
12.7
13.3
14.1
14.8
15.8
16.9
18.6
20.5
23.4
26.7
60°F
9.7
10.2
10.9
11.6
12.1
12.7
13.4
14.2
15.0
16.0
17.8
19.5
22.6
25.9
70°F
9.0
9.7
10.4
11.1
11.5
12.0
12.8
13.5
14.5
15.4
16.8
18.5
21.3
24.5
80°F
8.3
9.1
9.8
10.5
10.8
11.2
12.1
13.0
13.9
14.8
15.8
17.4
20.0
22.8
Grain
Temperature
15%
Days
18%
Days
20%
Days
22%
Days
24%
Days
26%
Days
28%
Days
30%
Days
40°F
898
195
85
54
38
28
24
20
50°F
451
102
46
28
19
16
13
11
60°F
242
63
26
16
10
8
6.5
5.5
70°F
147
37
13 8
5
4
3.5
3
80°F
109
27
10
6
4
3
2.5
2
*Allowable holding time for field-shelled corn at various grain temperatures and moisture.
Safe moisture for normal winter storage of shelled corn is about 15%. Grain to be stored through the
summer or long term, needs to be 1 to 3 points dryer.