Aprilaire 75 - Dehumidifier Control Manual

INTRODUCTION

Your control allows you to set the relative humidity level for your home and provides control of the dehumidifier from a convenient living space location. The Model 75 uses an onboard sensor to monitor the relative humidity in the space in which it is located and displays the measured relative humidity on the digital display.

SETTING THE DESIRED HUMIDITY LEVEL

The control will allow you to set the desired humidity level in your home and can be used to turn dehumidification On or Off.
Begin by pressing the ON button and ON will be displayed on the LCD Screen (see LCD display in Figure 1). Use the arrow buttons to set the control at 59% when first installed. Allow the dehumidifier to run until the initial setpoint has been reached, before deciding if you want to change the humidity setting.
Raise the setting if you prefer the air to be less dry; this will reduce the amount of time that the dehumidifier runs.
Lower the setting if you prefer the air to be more dry; this will increase the amount of time that the dehumidifier runs.
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 of time when first installed.

Energy Savings

1. Adjust the setting to be as high as is comfortable to reduce dehumidifier run time – if it feels clammy or smells damp or moldy lower the setting. To save energy, turn the dehumidifier control OFF when you open your windows just as you would with air conditioning.
2. If vacating your home for an extended period in the summer, set the RH at 59% and set your thermostat to as high as you are comfortable setting it 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 to help prevent mold while minimizing the amount of cooling energy used.

LCD DISPLAY

TURNING CONTROL ON/OFF

• Pressing the ON button will turn on the control.
• Pressing the OFF button will turn off the control.
• The control will continue to display the measured humidity when OFF.
• The humidity setting cannot be changed when the control is OFF.

CHANGING THE HUMIDITY SETTING

• The first press of either the or button will display the humidity setting on the LCD.
• Each subsequent push of the up or down buttons will change the setting by 1%.
• If a button is held down, the setting will continually change by 1% every 1/2 second for as long as the button is pressed.
• The control will exit the humidity setting screen 5 seconds after the last button press/release.

HOW DOES THE CONTROL WORK?

• When the measured humidity is greater than the setting, the control will turn on the dehumidifier and ON will blink on the LCD display.
• When the measured humidity falls 3% below the setting, the control will turn off the dehumidifier and ON will stop blinking, but remain displayed on the LCD.

CONTROL LIMITS

The control limits are used to make sure the dehumidifier does not run when conditions are outside of the operating limits. Dehumidifiers are not as effective when conditions are outside of the operating limits. For example, the dehumidifier will not remove much moisture when conditions are cool and dry. Control limits allow the dehumidifier to work efficiently within the operating range and turn off when conditions are outside of these limits.

• Dew Point Lower Limit: 40°F
• Temperature High Limit: 99°F

SEQUENCE OF OPERATION

• The dehumidifier will turn off if one of the control limits has been exceeded.
• If the control measures a dew point below 40°F OR a temperature above 99°F, the control will deactivate the dehumidifier output if actively dehumidifying, the dehumidifier will stop dehumidifying, and ON and * will blink on the LCD screen (see Figure 2).
• The control will resume normal operation when conditions fall back within the control limits.

CLEANING THE CONTROL

The surface of the Model 75 Dehumidifier Control can be cleaned with water or a non-abrasive household cleaner, including glass cleaner. Do not spray any liquid directly onto the control. Spray water or a cleaner onto a soft cloth and gently wipe the surface of the control.