Aprilaire 1750, 1770 - Dehumidifier Manual

PRINCIPLE OF OPERATION

120 volts may cause serious injury from electric shock. Disconnect electrical power before servicing.

Sudden operation may cause personal injury or property damage. Unplug the dehumidifier before servicing. Do not use solvents/cleaners on or near the control board.
READ AND SAVE THESE INSTRUCTIONS

The purpose of the Aprilaire^® Dehumidifier is to keep humidity in the house at acceptable limits to reduce the unwanted effects of high humidity. The dehumidifier gathers data from the HVAC system and measures the condition of the house air to decide when to run. An integrated air cycling feature can activate the HVAC blower to cycle air through the house to balance the indoor conditions. The dehumidifier can also operate an optional ventilation damper to bring in outside air.

OPERATING INSTRUCTIONS

There are three adjustable settings: the dryness setting, the air cycle period and the air cycle time within that period. The dehumidifier dryness can be set from "1" or "LESS" to "7" or "MORE" based on desired comfort level. Most installations should be initially set between "3" and "5" or "NORMAL" setting; however this can be adjusted to your individual needs. Air cycle period is set using the dip switches, and the potentiometer is used to set the air cycle time which are both located on the control board under the knob and are set during installation. If the cycle period is set to 1 hour and the cycle time potentiometer is set to 20 minutes, you will get 20 minutes of air cycling every hour. It is important to understand that the air cycling requirement – 20 minutes per hour in this example – may be satisfied by a heating, cooling, or fan call initiated by your thermostat, or if such calls do not satisfy the air cycling requirement, from a blower call initiated by the dehumidifier itself.

ADJUSTING THE DEHUMIDIFIER SET POINT

Use the main control knob (Figure 1) on the outside of the unit to set the dehumidifier dryness setting.
Start with a "NORMAL" setting for most installations. Moving the knob clockwise to "MORE" will make conditions drier. Moving the knob toward "LESS" allows for higher moisture levels.
Based on the indoor temperature, use the following table to determine the control knob setting to reach the desired RH value. The dehumidifier will work to achieve these values.

EXAMPLE: At an indoor temperature of 75°F with a dehumidifier control knob setting of 3, the dehumidifier will work to achieve an RH value of 53%.

NOTES:

1. %RH values are ±5% andare to be used as a GUIDE ONLY for initial set-up.
2. Indoor Temperature ismeasured at the inlet to the Model 1750/1770.

SETTING THE AIR CYCLE PERIOD AND CYCLE TIME

The air cycle period and cycle time are set during installation to meet the individual needs of your home. Detailed instructions are laid out in the dehumidifier installation manual.

OUTDOOR VENTILATION OPTION

If an Aprilaire^® Normally-Closed Damper (Model 6506) was installed in the HVAC outside air intake, then this damper will open whenever air cycling is active. This allows ventilation of outside air to be included into the air cycling of your indoor air.

VENTILATION CONTROL LIMITS
In a standard installation, your Aprilaire^® Dehumidifier will use measurements of outdoor temperature along with the user adjustable time settings to determine when to ventilate with outdoor air. The ventilation damper will not bring in outside air if the outside temperature is above 100°F or below 0°F. The ventilation damper will allow outside air to be brought in when the temperature is between 20°F and 0°F only during a heat call. In timed mode, outdoor air is taken based on the time setting only, regardless of temperature.

MAINTENANCE

AIR FILTER
Under normal circumstances, the filter in the dehumidifier should be cleaned or replaced once a year. A clean filter is necessary to prevent damage to the dehumidifier and allow it to function at full capacity. To remove the filter, first unplug or disconnect power to the dehumidifier, then remove the air filter via the access panel on the side of the dehumidifier. To clean, flush with warm water and detergent solution. After a clean or new filter is reinstalled, replace the access panel and reconnect power to the dehumidifier. The replacement filter for the dehumidifier is Model 4510 and is available from your installing contractor or from most other HVAC contractors in your area.

DRAIN
The drain trap or outlet should be checked and cleaned of debris annually by a qualified service professional.
NOTE: The drain trap needs to be primed with water prior to start-up and after extended periods of unit shut down (winter months).

www.aprilaire.com