Aprilaire 1872 User Manual

Model 1872 Dehumidifier

Installation and Operating Manual

SAFETY INSTRUCTIONS

WARNING

1. 120 Volts may cause serious injury from electric shock. Disconnect electrical power before starting installation or servicing. Leave power

disconnected until installation/service is completed.

2. Dropping may cause personal injury or equipment damage. Handle with care and follow installation instructions.

3. Sharp edges may cause serious injury from cuts. Use care when cutting plenum openings and handling duct work.

CAUTION

1. Read all instructions before beginning installation.

2. Improper installation may cause property damage or injury. Read instructions before installation, service or maintenance.

3. Do not use in pool applications. Pool chemicals can damage the dehumidifier.

4. Do not use solvents or cleaners on or near the circuit board. Chemicals can damage circuit board components.

5. Wait 24 hours before running the unit if it was not shipped or stored in the upright position

6. Do not use dehumidification to prevent window condensation in the winter. To address window condensation, use ventilation to lower

indoor humidity in the winter.

TABLE OF CONTENTS

SAFETY INSTRUCTIONS � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 1

SPECIFICATIONS � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �2

REMOVE SHIPPING BRACKET � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 2

LOCATION CONSIDERATIONS � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 3

DRAIN INSTALLATION � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 3

Condensate Pump and Float Switch� � � � � � � � � � � � � � � � � � � � � � � � � � � � �3

SETTING THE DESIRED HUMIDITY LEVEL � � � � � � � � � � � � � � � � � � � � � � � � �4

MAINTENANCE� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 5

DUCT COLLAR INSTALLATION� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �6

Control Location� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �6

DUCTING � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 7
Ducting in Basement � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �7
Ducting to Whole Home without an Air Handler� � � � � � � � � � � � � � � � � �8

TROUBLESHOOTING � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �9
Table 1 – Diagnostic Codes � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �9
Table 2 – Troubleshooting Guide � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 10

SERVICE PARTS � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �11

LIMITED WARRANTY � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 12

READ AND SAVE THESE INSTRUCTIONS

1

SPECIFICATIONS

CLIP OFF

REMOVE SCREWS (2)

MODEL 1872

Weight 113 lbs�

Capacity

AHAM DH-1-2008 80°F, 60% RH Conditions

Power
115 VAC, Single Phase, 60Hz

Dehumidifier Inlet Air Conditions

Filter MERV 8, washable

EXTERNAL STATIC PRESSURE ("w.c.) AIRFLOW (CFM)

Airflow

0.7"w.c. is maximum design external static pressure.

Dehumidification: 50°F – 104°F, 40°F dew point minimum

Ventilation: 40°F – 140°F, 0%RH – 99%RH (non-condensing)

0�0 310

0�2 270

0�4 225

0�6 175

130 pints per day @ 310 CFM

8�3A operating current

REMOVE SHIPPING BRACKET

IMPORTANT: Cut the strap securing the compressor shipping
support bracket and remove the strap, shipping bracket screws,
and bracket� See FIGURE 1�

FIGURE 1 – REMOVE SHIPPING BRACKET

DISCARD SHIPPING BRACKET
REINSTALL SCREWS (2)

PLASTIC
STRAP

90-2013

2

LOCATION CONSIDERATIONS

FOR PROPER

ELECTRICAL SERVICE ACCESS THIS SIDE

• Allow sufficient clearance for filter removal and
to prevent airflow obstruction

• Electrical service access will require the removal
of the side panel shown� Allow sufficient space
for service on this side of the unit�

FIGURE 2 – FILTER ACCESS CLEARANCE

6" MINIMUM

CLEARANCE

AIR FLOW

6 FT. POWER CORD

TOP VIEW

FILTER

MINIMUM

20"

CLEARANCE
FOR FILTER
(EITHER SIDE)

90-2020

DRAIN INSTALLATION

The drain outlet on the dehumidifier can be hard piped using a 3/4" PVC Slip x 3/4" MNPT fitting and 3/4" nominal drain tubing or the provided 3/4"
MNPT x 3/4" hose barb fitting and 3/4" clear PVC tubing can be used to drain the dehumidifier� Always maintain a constant downward slope from the
dehumidifier to the drain and do not allow soft tubing to curl up which may result in air lock� Note: PTFE thread seal tape is recommended for the
threaded connection and hand tighten only� If hard pipe is used, PVC primer and cement is recommended for the slip fit connection�

A level surface is required to ensure proper drainage from the dehumidifier�

Always install the dehumidifier in a condensate pan when locating in or above a finished space� Adhere to local codes regarding draining of the
condensate pan�

CONDENSATE PUMP AND FLOAT SWITCH

If a condensate pump is needed, install it in the condensate pan if
installed�

Install a condensate overflow safety switch (i�e� float switch) in the
condensate pan, remove the factory installed jumper wire between
the Float Switch terminals on the control and wire the float switch to
the dehumidifier as shown in FIGURE 3� Overflow safety switches on
condensate pumps can be wired to the Float Switch terminals in a
similar fashion�

FIGURE 3 – FLOAT SWITCH WIRING

DH DH

FLOAT

Switch

NORMALLY CLOSED

FLOAT SWITCH

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SETTING THE DESIRED HUMIDITY LEVEL

ON/OFF
SWITCH

1. Plug in dehumidifier and turn on/off switch ON� See FIGURE 4�

2. Press the ON/OFF button to turn the dehumidifier control ON� The display will show the

current setting, and the dehumidifier blower will turn on to start sampling the air�

3. The and buttons allow the humidity level to be set from 40% to 80% relative
humidity� Use the ON/OFF button to turn the dehumidifier ON or OFF�

Set the control at 55%RH when first installed� Allow the dehumidifier to run until it reaches

the setting before deciding if you want to change the setting� See FIGURE 5�

• If you prefer the air to be more dry, decrease the humidity setting�

• If you prefer the air to be less dry, increase the humidity setting�

4. After three (3) minutes of sampling, the measured humidity will be compared to the setting:

a. If the humidity is above the setting, the dehumidifier compressor turns on and “AIR

SAMPLING” will be replaced by “DEHUMIDIFYING”� The compressor remains on until the
measured humidity falls 3% RH below the setting� See FIGURE 6�

b. If the measured humidity is below the setting, the blowers turn off and the display

returns to showing the RH setting�

5. The dehumidifier will sample again every 60 minutes, or at any time if the humidity setting
is lowered�

Your comfort is the best measure of how to adjust your setting� When first installed, your
dehumidifier has to remove all the moisture that is initially in your home� The home acts like
a sponge so the moisture in the materials of your home is at the same level as the air� After
drying the air, the materials of the home will release moisture back into the air until they are
again at the same level� As a result, it is not uncommon for the dehumidifier to operate for an
extended period when first installed�

FIGURE 4 – ON/OFF SWITCH

90-1908

FIGURE 5

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�

ENERGY SAVINGS TIPS

Energy Savings Tip #1: Adjust the humidity setting to be as high as is comfortable to
reduce dehumidifier run time� If it feels clammy or “smells musty”, lower the humidity
setting� To save energy, turn the dehumidifier to OFF when you open your windows, just as
you would with air conditioning�

Energy Savings Tip #2: If vacating your home for an extended period in the summer, set
the RH at 55% and set your thermostat as high as you are comfortable setting it to in the
cooling mode� Consult with appropriate professionals regarding the highest temperature
that is safe for your pets or possessions� This will keep the humidity at a controlled level
while minimizing the amount of cooling energy used�

90-1853

FIGURE 6

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