Aprilaire 1700 owner manual Principle of Operation, II. Operating Instructions

I. PRINCIPLE OF OPERATION

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.

II. OPERATING INSTRUCTIONS

There are three adjustable settings: the dryness setting, the air cycle period and the air cycle time within that period. The dehumidifier can be set from “1” or “LESS DRY” to “7” or “MORE DRY” based on desired comfort level. Most installations should be initially set to the “3” 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.

1. 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 DRY” will make conditions drier. Moving the knob toward “LESS DRY” allows for higher moisture levels.

Based on the thermostat set point, use the following table to determine the control knob setting to reach the desired RH value. The dehumidifier will work to achieve these values.

			L
			A
		M
	R		3
N	O
2

LESSDRY 1

O

F

F

FIGURE 1

4 5

6

7 MOREDRY

	E	S	T
T

B2203436

%RH (± 5%) based on Control Knob Setting and Indoor Temperature

	Control Knob		Indoor Temperature (°F)
	Setting	65	70	75	80
1	- “LESS DRY”		84%	71%	60%
2		86%	73%	61%	52%
3	- “NORMAL”	74%	63%	53%	45%
4		64%	54%	45%	39%
5		55%	46%	39%	33%
6		47%	39%	33%	28%
7	- “MORE DRY”	40%	34%	28%	24%

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

NOTES:

1.%RH values are ±5% and are to be used as a GUIDE ONLY for initial set-up.

2.Indoor Temperature is measured at the inlet to the Model 1700.