T1 = 58F Current ambient temperature (Average from Form 2)
T2 = 124F Cooler intake temperature (Average from Form 2)
T3 = 100F Maximum expected ambient temperature that the truck will see
Duty Cycle = 20% See Section 5.1
No. of speeds: 1 or 2 (Circle one)
Tmax = 151F See Table 4
Tx = T3+T2-T1 The expected cooler intake temperature at maximum
ambient temperature
Tx = _100_+_124_-_58_ = _166F_
Tmax = _151F_ & Tx = _166F_ If Tmax is greater than or equal to Tx,
the ventilation is OK. If Tmax is less than Tx, more ventilation is required,
or the duty cycle must be reduced when the ambient air temperature is
greater than:
T3-(Tx-Tmax) = _100_ - (_166_ - _151_) = _85F_
Conclusion: Ventilation must be increased or the duty cycle reduced when
the ambient temperature is greater than 85F
Table 5 – Example Ventilation Analysis
VMAC – Vehicle Mounted Air Compressors
Toll Free:
1-888-241-2289 Local: 1-250-740-3200
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