Bathroom fan ORNO BF-100/HT 100 mm surface-mounted with humidity sensor and timer

The ORNO BF-100/HT surface-mounted bathroom fan with 100 mm duct connection is designed for efficient extraction of moisture and odors from bathrooms, toilets and small utility rooms. This compact fan integrates a humidity sensor and an adjustable timer to provide automatic operation: it activates when relative humidity rises above a set threshold and continues to run for a selected delay to ensure effective air exchange. The fan is suitable for wall or ceiling surface installation where a short duct run is available and offers a straightforward solution for improving indoor air quality and reducing condensation.

Advantages

The built-in humidity sensor enables automatic, demand-driven ventilation that reduces energy waste by operating only when needed. The adjustable timer allows post-ventilation to continue for a chosen interval, ensuring lingering moisture and smells are removed. Surface-mounted design simplifies installation without the need for recessed mounting, and the 100 mm duct connection fits common small ventilation ducts. The compact form and neutral appearance make it suitable for a variety of bathroom and utility room interiors.

Suitable for

• Family bathrooms and shower rooms
• Guest toilets and WC rooms
• Small laundry or utility rooms
• Wall or ceiling surface installation with 100 mm ducting

Key specifications

• Duct connection diameter: 100 mm
• Mounting type: surface-mounted (wall or ceiling)
• Integrated humidity sensor for automatic activation
• Adjustable timer for delayed switch-off
• Compact dimensions suitable for small spaces

How to use

Install the fan on a suitable wall or ceiling surface with access to a 100 mm duct or short ventilation outlet, following local electrical and building regulations. Connect the electrical supply according to the wiring instructions and set the humidity threshold and timer delay to the desired levels. During normal operation the fan remains idle until humidity exceeds the set point, at which point it switches on automatically; after humidity drops it continues to run for the selected delay to ensure adequate extraction. Periodically clean the grille and housing to maintain airflow and check electrical connections for safety.

Usage recommendations

Set the humidity sensor threshold slightly above typical ambient levels to avoid unnecessary cycling; use a moderate timer delay to balance moisture removal and energy use. For best performance, ensure the duct path is as short and straight as possible and that terminal vents are not obstructed.