Finder 7F.21.8.120.2055 – 120 V AC Reverse-Flow Exhaust Filter Fan, Size 2, 55 m³/h, IP54
The Finder 7F.21.8.120.2055 is a compact 120 V AC reverse-flow exhaust filter fan designed to remove warm air from industrial electrical enclosures, control cabinets and switchboards. Part of the Finder 7F Series, this Size 2 ventilation unit combines an electrically powered fan with a replaceable filter assembly to support effective thermal management in industrial and commercial electrical installations.
Featuring a nominal 120 V AC, 50/60 Hz supply and a 55 m³/h free-air airflow rating, the Finder 7F.21.8.120.2055 provides forced exhaust ventilation for electrical cabinets containing heat-generating components such as power supplies, relays, drives and electronic control equipment.
Unlike a conventional intake filter fan, this reverse-flow version is designed to extract air from the enclosure. It is particularly useful where the ventilation system requires an active exhaust fan rather than relying solely on a passive outlet.
The unit features a 155 × 155 mm front housing, a light grey RAL 7035 finish, a replaceable filter mat and an IP54 protection rating when correctly installed. Its compact, panel-mounted construction makes it a practical solution for machine builders, electrical engineers, control panel manufacturers and maintenance professionals.
Key Advantages
- Reverse-flow exhaust operation actively removes warm air from electrical enclosures.
- 55 m³/h free-air airflow supports ventilation of suitable industrial control cabinets.
- 120 V AC supply provides compatibility with appropriately rated control circuits.
- 50/60 Hz operation supports common AC supply frequencies.
- Size 2 construction offers a balance between airflow capacity and installation space.
- IP54 protection helps limit dust ingress and water splashing when correctly installed.
- Replaceable filter mat simplifies inspection and routine maintenance.
- Integrated fan and filter assembly combines forced ventilation with enclosure filtration.
- Compact 155 × 155 mm front dimensions support installation in suitable cabinet panels.
- Low-noise operation makes it suitable for a range of industrial environments.
- Snap-in mounting arrangement supports straightforward installation.
- Light grey RAL 7035 housing complements common industrial enclosure finishes.
- Compatible Size 2 ventilation accessories allow the complete airflow system to be configured for the application.
Key Features
- Finder 7F Series electrical enclosure ventilation fan.
- Type 7F.21 reverse-flow exhaust configuration.
- Size 2 filter fan assembly.
- 120 V AC nominal operating voltage.
- 50/60 Hz supply frequency.
- 55 m³/h free-air volume flow.
- Approximately 32.4 CFM free-air airflow.
- 30/25 W rated power at 50/60 Hz.
- IP54 ingress protection rating.
- NEMA Type 12 classification, subject to correct installation.
- 155 × 155 mm front dimensions.
- Approximately 66.2 mm installation depth.
- Approximately 42 dB(A) noise emission.
- RAL 7035 light grey housing.
- Integrated electric fan motor.
- Replaceable synthetic fibre filter mat.
- Compatible with Finder 07F.25 Size 2 replacement filter mats.
- Suitable for enclosure wall or panel installation.
- Snap-in mounting design.
- Designed for industrial control cabinet thermal management.
Technical Specifications
- Manufacturer: Finder
- Series: 7F Series
- Type: 7F.21
- Model: 7F.21.8.120.2055
- Product category: Electrical enclosure ventilation
- Product type: Reverse-flow exhaust filter fan
- Ventilation direction: Exhaust / air extraction
- Fan size: Size 2
- Nominal operating voltage: 120 V AC
- Voltage type: AC
- Operating frequency: 50/60 Hz
- Free-air volume flow: 55 m³/h
- Free-air airflow: Approximately 32.4 CFM
- Rated power at 50 Hz: 30 W
- Rated power at 60 Hz: 25 W
- Front housing width: 155 mm
- Front housing height: 155 mm
- Installation depth: Approximately 66.2 mm
- Housing colour: Light grey
- RAL colour: RAL 7035
- Ingress protection: IP54
- NEMA classification: Type 12
- Noise emission: Approximately 42 dB(A)
- Fan motor: Integrated
- Filter included: Yes
- Filter mat: Replaceable
- Compatible replacement filter mat: Finder 07F.25
- Mounting method: Snap-in panel mounting
- Suitable installation: Electrical enclosure wall or panel
- Matching Size 2 exhaust filter: Finder 7F.02.0.000.2000
- Compliance: RoHS compliant
How the Finder 7F.21 Reverse-Flow Exhaust Fan Works
The Finder 7F.21.8.120.2055 uses an electrically powered fan to extract air from an electrical enclosure.
During normal operation, heat-producing electrical components raise the temperature of the air inside the cabinet. The reverse-flow fan draws this warmer air towards the enclosure outlet and expels it through the fan assembly.
As air is removed, replacement air enters through a suitable inlet or ventilation opening. This establishes an airflow path that can help reduce the internal cabinet temperature.
The fan is rated for a free-air volume flow of 55 m³/h. This is the airflow measured under free-flow conditions and should not be interpreted as the guaranteed airflow through every installed enclosure.
The actual airflow depends on factors including filter resistance, inlet dimensions, enclosure layout and pressure losses through the complete ventilation system.
For effective cooling, the fan must be correctly sized for the cabinet's internal heat load and the surrounding ambient temperature.
Reverse-Flow Exhaust Fan Versus Standard Intake Filter Fan
The primary difference between the Finder 7F.21 and standard Finder 7F.20 filter fan arrangements is the direction of airflow.
A standard intake filter fan is typically used to draw cooler external air into an electrical enclosure. The air then circulates through the cabinet before leaving through an exhaust opening.
The Finder 7F.21.8.120.2055 instead provides active exhaust ventilation, drawing air out of the cabinet.
This arrangement can be useful where enclosure layout, equipment positioning or the required airflow path makes active air extraction preferable.
The choice between intake and exhaust ventilation should consider the complete system, including dust exposure, filtration, cabinet pressure and the location of heat-producing equipment.
IP54 Protection for Industrial Electrical Enclosures
The Finder 7F.21.8.120.2055 has an IP54 ingress protection rating when installed in accordance with the manufacturer's instructions.
IP54 indicates protection against harmful dust ingress and splashing water under the relevant test conditions.
The fan's housing and filter assembly help support enclosure ventilation while limiting the entry of airborne contaminants through the fan opening.
Correct installation is essential. The final ingress protection of the complete electrical cabinet depends on the enclosure construction, seals, other openings and all fitted ventilation components.
The product is also listed with a NEMA Type 12 classification, making it suitable for appropriately designed indoor industrial enclosures.
It should not be assumed to provide unrestricted outdoor weather protection or resistance to high-pressure water jets.
Replaceable Filter Mat for Easy Maintenance
The Finder 7F.21.8.120.2055 includes a filter assembly designed for routine inspection and maintenance.
Its replaceable filter mat helps manage airborne contamination around the ventilation opening. Over time, accumulated dust can increase airflow resistance and reduce cooling performance.
The compatible Finder 07F.25 replacement filter mat allows the filter material to be renewed without replacing the complete fan assembly.
The inspection and replacement interval should reflect the surrounding environment. Electrical cabinets installed in dusty production areas may require more frequent maintenance than those located in clean electrical rooms.
Regular filter maintenance helps preserve ventilation performance and reduces the risk of excessive enclosure temperatures caused by restricted airflow.
Thermal Management for Control Panels and Switchboards
Electrical control cabinets often contain components that generate heat during operation, including contactors, relays, power supplies, transformers, variable speed drives and electronic control modules.
If this heat is not adequately managed, the internal cabinet temperature can rise above the recommended operating limits of the installed equipment.
The Finder 7F.21.8.120.2055 helps address this by providing forced exhaust airflow, removing warm air and supporting circulation through the enclosure.
The required ventilation capacity depends on the total internal heat dissipation, ambient temperature, target cabinet temperature and the pressure losses of the ventilation system.
For best results, the fan should be selected as part of a complete thermal management design rather than solely on its nominal free-air airflow rating.
Installation and Electrical Considerations
The Finder 7F.21.8.120.2055 is designed for mounting into a suitable electrical enclosure wall or panel using its snap-in mounting arrangement.
The unit has a 155 × 155 mm front housing, allowing it to be incorporated into compatible Size 2 enclosure ventilation arrangements.
The fan requires a nominal 120 V AC electrical supply at 50/60 Hz.
Important: This model is not a 230 V AC fan. It must not be connected directly to a standard UK 230 V mains supply unless a correctly rated voltage conversion arrangement is provided.
The exact panel cut-out, mounting clearances, terminal connections and protective arrangements should be confirmed against the manufacturer's installation drawing before fitting.
The fan can be incorporated into a temperature-controlled ventilation system using a suitable thermostat or control device, allowing ventilation to operate when the cabinet reaches a predetermined temperature.
Typical Applications
- Industrial electrical control cabinets.
- Electrical switchboard ventilation.
- Machinery control panel cooling.
- Industrial automation enclosures.
- Power supply and relay cabinet ventilation.
- Manufacturing and production equipment.
- OEM machinery and electrical panel manufacturing.
- Building services electrical enclosures.
- Industrial process control installations.
- Electrical distribution cabinets.
- Cabinets requiring active exhaust ventilation.
- Temperature-controlled ventilation systems.
- Control panels operating with a suitable 120 V AC supply.
