Combustion air damper and replacement air damper
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 #3: Forced Air Furnace having a combustion air supply duct and a replacement air supply duct.
ADDED: 1. Combustion Air Damper (HOM-0x11-SF1) 2. Replacement Air Damper, Power Close damper recommended. (HAC-0x10-OPC).
OPERATION: 1. Replacement Air Damper is inter-connected to the Combustion Air Damper so that both dampers open during the heating cycle and close when the fire stops. 2. Optional switch (i.e. toggle switch, timer, de-humidistat) allows full control of Replacement Air damper to open provided it is the Power Close (PC) type.
0828 Printed in Canada
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