Instructions / Assembly

[3]
MODEL VFB25AC / VFB25AD/ VFB25ACH / VFB25ADH/ VFB25AEH / VFB25AX
3-1. Insert the suspension bracketⅠ into the bracket cover of adaptor side and insert the
suspension bracketⅡ and Ⅲ into the back of the fan body.
3-2. Insert the fan between joists. Make sure the fan body is level and perpendicular with the
joist.
3-3. Ensure the distance between ceiling and fan body for the thickness of grille.
3-4. Secure the suspension bracket to joists by using screw.
3-5. Secure the suspension bracket to fan body by using screw.
3-6. Follow step 4 to 7 of installation to complete the installation work.
4. Duct connection
4-1. Insert the duct into the duct connector and tape all ductworks connection to make
them secure and air tight.
4-2. Install the duct with a gradient 1°~2° to the outside.
5. Connect wiring
5-1. Follow all local electrical and safety codes.
5-2. NEVER place a switch where can be reached from a tub or shower.
5-3. Connect wires as shown in wiring diagrams.
5-4. Using wire nuts, connect house power cable to ventilating fan wires.
5-5. 14 AWG (2.1 mm2) is the smallest conductor that shall be used for branch-circuit wiring.
6. Test run and grille attachment
6-1. When the power on, check for abnormal vibration or sound.
6-2. Insert the mounting springs into the slots and mount the grille to the body.
7. Operation
Humidity Models: VFB25ACH, VFB25ADH, VFB25AEH
Manual operation for humidity control mode & full speed mode. Power on the fan once and
fan is in humidity mode. Fan blades will spin or not spin depending on level of humidity in
the environment.
7-1 Humidity sensor mode:
 Blue LED indicator lights show humidity sensor mode
 Humidity control automatically turns fan ON when humidity above 60%RH
 Airflow increase with humidity linearly as below picture.
 Saves energy because unit runs only when humidity level is high
7-2. Full speed mode:
 Amber LED indicator lights show full speed mode
 Cycling switch to run full speed mode when you need.
Single Models: VFB25AD, VFB25AC
7-3. Single speed control mode: Turn on the power switch to operate ON or OFF.
Dual Speed Model: VFB25AX
7-4. Low speed control mode: Turn on the power switch to operate low speed mode, and
LED is green.
7-5. High speed control mode: Cycling ON/OFF switch to operate high speed mode, and LED
is amber.