Honeywell H1008A-1008 H1008A1008 HumidiCalc Auto Humidistat, 24V

H1008A1008 humidistat provides 24 volt automatic control for by-pass flow-thru, powered flow-thru, steam and drum humidifiers in central heating systems. Color Taupe.

The H1008 determines the outside temperature based on the duty cycle of the furnace or with an optional outdoor sensor. Simply the more the furnace runs the colder the outside temperature.

This feature of estimating the outside temperature based on the furnace run time is called Humidi
Calc. Humidi
Calc is software that is built-in to the H1008 and is not user installed or accessible.

Humidi
Calc only works on a single-stage furnace (single speed). A two-stage or variable-speed furnace would have low and high heat. The furnace starts on low heat and if the house does not come up to temperature within a preset time then the furnace switches to high heat. High heat would have an increased flame and blower.

Humidi
Calc can not infer the outside temperature on a two-stage or variable-speed furnace. These furnaces require an outside temperature sensor (C7089H).

The H1008 requires a connection to full-time 24vac power as well as 24v which is only present when the furnace is running.

Specifications:

Description: Dew point Control of Humidifier
Application: Humidification
Type: Humidity Control
Voltage: 24 Vac
Electrical Rating: 2.0 A at 24 Vac Humidifier Contacts
Color: Taupe
Mounting: Duct mount only
Differential: 2 F
Temperature Range: 45 F to 88 F
7 C to 31 C
Operating Range: 95% RH at 95 F, non-condensing
Dimensions (in): 4-7/32 high x 5-1/4 wide x 1-31/32 deep
Dimensions (mm): 107 mm x 133 mm x 50 mm