Today a similar cotton/mixed load was used to test the dryer with the new hood.
A) From 0 to 10 min, the temp was increasing slowly from 66F to 117F (51F increase)
B) From 10 to 20 min, the temp was increasing very slowly from 117F to 122 (only 5F increase).
C) From 20 to 30 min, the temp was increasing slowly from 122F to 151F (29F increase).
During the periods of A, B and C, the inlet thermostat was switched ON/OFF one of the heating element to maintain the set-temperature of the inlet.
D) From 30 min to 45 min, the outlet thermostat took over to the set-temperature of the outlet. The outlet temp as measured varied from 133F to 154F. When the temp exceeded 154F, both heating elements were switched OFF. When the temp fell below 133F, both heating elements were switched ON.
E)From 45 min to 51 min (cooling down period) the outlet temp fell slowly to 102F and at 51 min the buzzer sounded to end the drying cycle
Note:
1) There is about 10% reduction in the drying cycle with the new hood.
2) But I think that there could be about 2 to 5% reduction in heating cost because the inlet temperature is maintained by the Control Inlet Thermostat.
3) The temperature variation at the outlet is about 3 deg F with the Control Inlet Thermostat in active mode.
4)The temperature variation at the outlet is about 20F (say 133F to 154F) with the Control Inlet Thermostat in active mode.