24Vac vent switch with relay, replacement air damper Power Close with exhaust fan
HMI Hoyme Manufacturing Inc. Special Note: Circuits are colored for clarification only and are not necessarily those found in actual installations.
Diagram #8B1: Forced Air Furnace having a replacement air supply duct together with an exhaust fan controlled by a designated 24Vac ventilation switch.
1. Replacement Air Control Damper, Power Close (HAC-0x1O-OPC)
2. 24Vac Ventilation Switch. 3. 24Vac Relay Adaptor (ADP-0241-10A) to function as a control centre connected to the exhaust fan.
OPERATION: 1. Furnace fires with thermostat signal and opens the replacement air damper. 2. 24Vac Ventilation Switch turns on Ventilation Fan, opens Replacement Air Damper and turns on Furnace Fan simultaneously. 3. Optional Switch (i.e. toggle switch, de-humidistat) allows full control of Replacement Air damper to open as required.
N.B. Replacement Air Damper is not affected by the ‘Manual’ setting of the furnace fan.
0845 Printed in Canada