Aprilaire 1770A - FLOAT SWITCH

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16. Subtract the discharge air moisture content from the inlet air moisture content to determine the
amount of moisture being removed by the dehumidifier.
Inlet Air Moisture ______ ppd @ ___ °F, ___ % RH
Discharge Air Moisture ______ ppd
Dehumidifier Capacity______ ppd
17. Compare the capacity to the approximate performance in the table below. Performance should
be within about 20% of the capacity listed below:
Inlet Air RH
Inlet Air Temperature (°F)
60
65
70
80
50%
N/A
45 ppd
57 ppd
75 ppd
60%
43 ppd
66 ppd
78 ppd
90 ppd
Water Leaks
Water collects in the drain pan below the coils and is directed through the drain tube to the outlet at the
outlet side of the dehumidifier. A custom running trap is provided with the dehumidifier that is deeper
than a standard running trap – do not use any other trap than what is provided with the unit. The
models 1710A, 1750A and 1770A are negative pressure cabinets and the trap prevents air from being
pulled in through drain tube and subsequently pushing water back up into the drain pan.