Install Instructions

ManualsBrandsAprilaire ManualsDehumidifiersModel Dehumidifier for Crawl Spaces (80 Pints Per Day)

START-UP

1. Press the ON/OFF button to turn the dehumidifier control ON. The

display will show the current dew point or %RH setting, and the

dehumidifier blower will turn on to start sampling the air.

“AIR SAMPLING” will show on the display.

2. Use the UP or DOWN button to adjust the dew point setting or

%RH setting as desired. The recommended initial setting is 3

using dew point control or 59%RH, for preservation and preventing

condensation on floor joists. See Table 1.

3. After three (3) minutes of sampling, the measured dew point or

%RH will be compared to the setting:

a. If the dew point is above the setting or above the %RH setting,

the dehumidifier compressor turns on and “AIR SAMPLING” will

be replaced by “DEHUMIDIFYING”. The compressor remains

on until the measured dew point falls below the setting or

measured %RH falls 3% below the setting.

b. If the dew point or %RH is below the setting, the blowers turn

off and the display returns to showing the setting.

4. The dehumidifier will sample again every 60 minutes, or at any

time if the humidity setting is lowered.

NOTE: For Start-Up when using a Model 76 Control, reference the

Model 76 Installation Instructions.

TABLE 1 – %RH (+/- 5%) Based on Dryness Setting and

Crawl Space Temperature

Dryness Setting

& Dew Point

Crawl Space Temperature

60°F 65°F 70°F

1 – Less, 65°F DP 84%

2 – 61°F DP 87% 73%

3 – Normal, 57°F DP 90% 75% 63%

4 – Normal, 53°F DP 78% 65% 55%

5 – Normal, 49°F DP 67% 56% 47%

6 – 46°F DP 60% 50% 42%

7 – Most Dry, 42°F DP 51% 43% 36%

EXAMPLE: At a crawl space temperature of 70°F and a dryness level

setting of 3 (57°F DP), the dehumidifier will work to achieve a 63%

relative humidity level.

• The %RH values are +/- 5% and are to be used as a GUIDE ONLY.

• The crawl space temperature is measured at the dehumidifier inlet.

Your dehumidifier is equipped with two features that protect against unwanted energy consumption. Defrost is a normal operating mode that

helps to prevent significant ice formation on the refrigeration system coil. The dehumidifier display will show “DEFROSTING” when operating

in this mode. This mode can occur when there is not enough air moving through the dehumidifier or if the temperature and/or humidity of

the incoming air is too low. The second protection feature is the E8 code. E8 on the dehumidifier display indicates that the air entering the

dehumidifier is below 50°F or above 104°F, or the dew point of the incoming air is below 40°F. There would be a significant reduction in

dehumidifier efficiency if the dehumidifier operated outside of these conditions. Low dew point conditions can be seen in some basements

or crawl spaces and usually occur in the Winter and Spring months. The dehumidifier continues to monitor the incoming air and when the

conditions are within the operating range, E8 will be removed from the display and dehumidification will begin as needed.

90-1854

Press and hold the ON/OFF button

and MODE buttons for 3 seconds.

The measured humidity, AIR

SAMPLING and TEST will show

on the display. The ALERT LIGHT

will turn on and stay on until the

system check is “DONE”.

90-1854

After three (3) minutes the

dehumidifier compressor will

turn on and DEHUMIDIFYING will

replace AIR SAMPLING on the

control screen.

90-1854

After one minute of compressor

operation, all outputs will turn off

and DONE will blink for 3 seconds

and then return to the OFF screen.

SYSTEM CHECK