Finder 7F.21.8.120.2055.0 – 120 V AC Reverse-Flow Exhaust Filter Fan, Size 2, 55 m³/h
The Finder 7F.21.8.120.2055.0 is a reverse-flow exhaust filter fan from the Finder 7F Series, designed to provide forced ventilation for electrical enclosures, industrial control cabinets and switchboards.
The product is listed under the extended part number 7F.21.8.120.2055.0. Finder's published ordering information identifies the corresponding base model as 7F.21.8.120.2055, a Size 2 reverse-flow filter fan operating at 120 V AC with a nominal free-air volume of 55 m³/h. The additional .0 suffix should be confirmed against the supplier's ordering documentation when exact variant identification is required.
Unlike a conventional intake filter fan, the Finder 7F.21 is designed to extract warm air from an electrical enclosure. This makes it useful for ventilation systems where active exhaust airflow is preferred.
Its compact construction, replaceable filter mat and panel-mounting design make it a practical ventilation component for industrial automation, machinery control and electrical distribution applications.
Key Advantages
- Reverse-flow exhaust operation actively removes warm air from electrical enclosures.
- 55 m³/h nominal free-air volume provides forced ventilation for suitable cabinet installations.
- 120 V AC operation supports appropriately rated industrial control supplies.
- 50/60 Hz compatibility allows operation with common AC supply frequencies.
- Size 2 construction provides a compact ventilation solution.
- 125 × 125 mm nominal panel cut-out supports installation into compatible enclosures.
- Integrated fan and filter assembly combines active airflow with a serviceable ventilation opening.
- Replaceable filter mat simplifies routine maintenance.
- Low-noise design supports use in industrial electrical cabinets.
- Suitable for thermostat-controlled operation with an appropriately rated control device.
- Finder 7F Series compatibility supports coordinated enclosure ventilation designs.
- Industrial enclosure application makes it suitable for control panels, switchboards and machinery cabinets.
Key Features
- Finder 7F Series enclosure ventilation product.
- Type 7F.21 reverse-flow filter fan.
- Extended product reference: 7F.21.8.120.2055.0.
- Corresponding published base model: 7F.21.8.120.2055.
- Reverse-flow exhaust configuration.
- Size 2 fan assembly.
- Nominal operating voltage: 120 V AC.
- AC supply frequency: 50/60 Hz.
- Nominal free-air volume: 55 m³/h.
- Approximate free-air volume: 32.4 CFM.
- Nominal panel cut-out: 125 × 125 mm.
- Integrated electric fan motor.
- Replaceable filter element.
- Designed for installation into enclosure sidewalls or panels.
- Suitable for industrial electrical cabinet ventilation.
Technical Specifications
- Manufacturer: Finder
- Series: 7F Series
- Type: 7F.21
- Requested product reference: 7F.21.8.120.2055.0
- Published base model: 7F.21.8.120.2055
- Product category: Electrical enclosure ventilation
- Product type: Reverse-flow exhaust filter fan
- Airflow direction: Exhaust
- Fan size: Size 2
- Nominal supply voltage: 120 V AC
- Supply type: AC
- Frequency: 50/60 Hz
- Nominal free-air volume: 55 m³/h
- Nominal free-air volume in imperial units: Approximately 32.4 CFM
- Panel cut-out: 125 × 125 mm nominal
- Panel cut-out tolerance: +1.0 mm
- Fan motor: Integrated
- Filter element: Replaceable
- Installation: Electrical enclosure wall or panel
- Application environment: Indoor electrical enclosures
- Colour: Grey RAL 7035 for the standard base version; confirm the extended suffix variant before ordering
- Additional .0 suffix: Exact ordering significance not independently established
How the Finder 7F.21 Reverse-Flow Exhaust Fan Works
The Finder 7F.21 reverse-flow filter fan uses an electric motor to draw warm air from inside an electrical enclosure and discharge it through the ventilation opening.
As heat-generating electrical components operate, the temperature of the air inside the cabinet may rise. Active exhaust ventilation helps remove this warm air, allowing replacement air to enter through a suitable inlet.
This circulation can help maintain more suitable operating conditions for electrical components such as relays, power supplies, controllers, contactors and electronic modules.
The 55 m³/h rating describes nominal airflow under free-flow conditions. Actual airflow in an installed cabinet will be affected by the filter condition, inlet arrangement, enclosure resistance and overall ventilation design.
Reverse-Flow Exhaust Versus Standard Intake Ventilation
The Finder 7F.21 range uses reverse-flow operation to extract air from an enclosure.
By comparison, standard 7F.20 filter fans are generally used to introduce air into an enclosure.
An intake fan can create a slightly positive cabinet pressure, whereas an exhaust fan may create negative pressure depending on the inlet and outlet arrangement.
The appropriate configuration depends on the installation environment, dust exposure, required airflow direction and the positioning of heat-producing equipment.
Size 2 Panel Installation
The Finder 7F.21.8.120.2055 base model uses the Finder Size 2 enclosure cut-out format.
Finder's published ordering information specifies a nominal 125 × 125 mm panel opening with a +1.0 mm tolerance for Size 2 units.
Before cutting an enclosure panel, installers should confirm the mounting drawing, enclosure wall thickness and any gasket or retention requirements against the supplied product.
The unit should be positioned to encourage airflow through the areas of the cabinet where heat is generated.
Filter Inspection and Maintenance
The fan assembly incorporates a serviceable filter element. Over time, dust and airborne particles can accumulate within the filter and increase resistance to airflow.
Regular inspection helps maintain ventilation performance and reduces the likelihood of overheating caused by restricted airflow.
The filter should be replaced using a compatible Finder Size 2 replacement element specified for the exact fan assembly.
Maintenance intervals should be based on operating hours, ambient dust levels and the conditions surrounding the electrical enclosure.
120 V AC Electrical Supply Requirements
The Finder 7F.21.8.120.2055.0 corresponds to a 120 V AC fan configuration.
It must be connected only to an electrical supply within the manufacturer's permitted operating range.
Important for UK installations: Standard UK mains voltage is nominally 230 V AC. This 120 V AC fan must not be connected directly to a 230 V AC supply. Use a correctly rated supply arrangement or select a suitable 230 V AC model.
The fan may be controlled using a suitable cabinet thermostat or switching device, provided that the controller is appropriately rated for the fan's voltage and motor load.
Typical Applications
- Industrial electrical control cabinets.
- Automation and PLC enclosures.
- Machinery control panel ventilation.
- Electrical switchboards.
- Power distribution cabinets.
- Industrial process control installations.
- Building services control panels.
- OEM electrical enclosure manufacturing.
- Cabinets requiring active warm-air extraction.
- Temperature-controlled ventilation arrangements.
- Industrial equipment using a suitable 120 V AC control supply.
