24Vac vent switch, combustion air, and replacement air
HMI Hoyme Manufacturing Inc. Special Note: Circuits are colored for clarification only and are not necessarily those found in actual installations. Wires of the Combustion Air Damper, however, are colored as shown.
Diagram #7: Forced Air Furnace having a combustion air and a replacement air supply duct together with an exhaust fan controlled by a designated ventilation switch and/or bathroom timer that sends a 24Vac signal to the furnace area.
1. Combustion Air Damper (HOM-0x11-SF1)
3. Ventilation Switch and/or bathroom timer to supply 24Vac to the furnace area.
4. 24Vac Relay Adaptor (ADP-0241-05A) to function as a control centre.
1. Combustion Air Damper and Replacement air damper open during furnace firing.
2. Ventilation Switch and/or bathroom timer turns on Exhaust Fan, opens Replacement Air Damper and turns on Furnace Fan simultaneously.
3. Optional switch (i.e. toggle switch, timer, de-humidistat) allows full control of Replacement Air damper to open as required provided it is a Power Close type.
N.B. Replacement Air Damper is not affected by the ‘Manual’ setting of the furnace fan.
1222-ld - Printed in Canada
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