24Vac vent switch, combustion air, and replacement air with two exhaust fans and two individual timers
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 #7A: A Forced Air Furnace, a combustion air supply duct, a replacement air supply duct, two exhaust fans, two individual timers and an adaptor ADP-0241-05A.
3. Two exhaust fans having individual timers with switching capabilities
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/Timer (either one) turns on Exhaust Fan(s), 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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