Lifebreath AH40DHW, AH60DHW, AH40BHW, AH80BHW, AH60BHW Optional Dehumidistat, Outside

Optional Dehumidistat

Dehumidistat to
Setting		Relative
		Conditions
Outside
			TER:					t
	WIN
Set deh			umidista						.
					to		40%
	een	30%
betw				too dry,
If	home is					setting.
adjust to higher								id,
If home		is too hum
		lower sett						ing.
adjust to
	SUMMER					:	tat
		umidis
Set deh					.
	to OFF

An optional dehumidistat can be connected to the furnace to help eliminate excessive moisture during the heating season. When the dehumidistat senses moisture in excess of the control setpoint, the blower will be overridden into high speed. This will increase the ventilation airflow and create a dehumidification affect. Typical settings are between 30-40 during the winter and OFF for all other seasons.

The dehumidistat will connect to R&G terminals on the furnace.

Part # 99-130W Note: Do not use dehumidistat for hot southern climates.

When using a Dehumidistat or Interface Relay to initiate high speed blower operation on a furnace, certain thermostats will initiate the outdoor cooling condenser when R and G are closed.

Use this wiring configuration to stop the Dehumidistat from initializing the condenser unit. This problem can occur at the thermostat because the Y terminal is connected to the G terminal internal to the stat. When R and G are closed at the furnace (by dehumidistat or relay) 24 Volts is sent to G at thermostat. 24 Volts is then sent through Y which will initiate outdoor condenser. The relay will isolate this problem.

NOTE: This problem does not occur with all thermostats, therefore it is important to fully commission the installation to determine if this relay configuration is required.

Interface Relay or Dehumidistat

24 Volt

Relay

R G W Y C

NO

COM

NC

R G W Y

T-stat

Furnace	TB-102
	1099

20