Allegro 20" Axial AC High Output Metal Blower — Maximum Airflow for Demanding Confined Space Ventilation
The Allegro 9525-50 is a 20-inch, 2 HP axial AC blower engineered for applications requiring maximum air output in construction, industrial, manufacturing, and confined space environments. Built around a 16-gauge cold rolled steel housing with an epoxy powder-coated safety orange finish, this unit delivers up to 7,500 CFM of free-air flow from a dual-voltage 115V–230V AC motor. It is UL Listed and certified to CSA Standard C22.2 No. 113, making it a code-compliant solution for professional ventilation work.
Technical Specifications
| Specification | Details |
|---|---|
| Brand | ALLEGRO |
| Item # | 9525-50 |
| UPC | 741851952550 |
| Size | 20" |
| Motor | 2 HP |
| Voltage | 115V–230V AC, 60 Hz |
| Blade Count | 4 |
| Fan Material | Glass reinforced polypropylene (PPG) four-blade fan with aluminum hub |
| Housing Material | 16-gauge cold rolled steel |
| Housing Finish | Epoxy powder-coated safety orange |
| Grill | Steel/chrome plated |
| Airflow — Free Air | 7,500 CFM |
| Airflow — One 90° Bend | 6,700 CFM |
| Airflow — Two 90° Bends | 6,130 CFM |
| Weight | 97 lbs (83 lbs per linecard) |
| Country of Origin | United States |
| Applications | Construction, Industrial, Manufacturing, Confined Space |
| Certifications | UL Listed; Certified to CSA Standard C22.2 No. 113 |
| Mounting | Interchangeable flange for intake or exhaust side mounting |
| Feet | 4 rubber feet |
Available Items
| Item # | Description | Size |
|---|---|---|
| 9525-50 | 20" Axial AC High Output Metal Blower | 20" |
Compared to the standard 20" axial model (9525) rated at 4,650 CFM free air with a ½ HP motor, the 9525-50 delivers 7,500 CFM free air with a 2 HP motor — a substantially higher output suited for larger confined spaces or longer duct runs where airflow volume is critical. The dual-voltage design (115V–230V) also provides flexibility across different site power configurations without requiring a separate model.
Key Features & Benefits
High Output 2 HP Motor
The 2 HP motor drives up to 7,500 CFM of free-air flow, maintaining 6,700 CFM through one 90° bend and 6,130 CFM through two 90° bends. This sustained output across duct configurations means contractors can ventilate larger or more complex confined spaces without sacrificing airflow performance.
Dual-Voltage Operation (115V–230V AC)
The 115V–230V AC, 60 Hz motor accommodates a wide range of site power supplies, reducing the need for additional electrical infrastructure or step-down transformers. This flexibility makes the blower practical across diverse job sites and international deployments.
16-Gauge Cold Rolled Steel Housing
The heavy-gauge steel housing resists impact and deformation in demanding job site conditions. The epoxy powder-coated safety orange finish provides corrosion resistance and high visibility on busy work sites.
Interchangeable Flange for Intake or Exhaust Mounting
The interchangeable flange allows the blower to be configured for either intake (fresh air supply) or exhaust (contaminated air removal) without purchasing a separate unit. This dual-function capability reduces equipment costs and simplifies inventory for contractors managing multiple confined space operations.
Integrated Carrying Handles
Built-in carry handles allow a single worker to reposition the blower between job sites or within a work area without additional lifting equipment. Combined with four rubber feet for stable placement, the unit is designed for practical field use.
Glass Reinforced Polypropylene (PPG) Four-Blade Fan with Aluminum Hub
The PPG fan blades offer resistance to chemical exposure and impact while the aluminum hub provides structural rigidity at high rotational speeds. This combination supports reliable, long-service operation in industrial and construction environments.
UL Listed and CSA Certified
The 9525-50 is UL Listed and certified to CSA Standard C22.2 No. 113 (Fans and Ventilators), confirming it meets recognized North American safety standards. This certification supports compliance with OSHA confined space ventilation requirements.
Common Applications
Confined Space Ventilation
Designed specifically for confined space work, this blower supplies or exhausts air in manholes, vaults, tunnels, tanks, vessels, silos, and similar enclosed environments where OSHA-compliant ventilation is required prior to and during worker entry.
Construction Site Ventilation
Used on construction sites to ventilate enclosed structures, below-grade work areas, and partially completed buildings where fresh air circulation is needed for worker safety and comfort.
Industrial and Manufacturing Facilities
Suitable for ventilating hoppers, storage bins, pipelines, ductwork, and other industrial confined spaces in manufacturing and processing plants where high airflow volume is required.
Tunnel and Underground Work
The high CFM output and ability to maintain airflow through multiple duct bends makes this blower effective for tunnel ventilation and other underground applications requiring air movement over longer distances.
Shipyard and Refinery Applications
The steel construction and high output capacity suit demanding environments such as shipyards and refineries where robust, high-volume ventilation equipment is required for tank and vessel entry operations.
Compatible Materials
- Standard flexible ducting (sold separately)
- Compatible with axial inline booster blowers as a velocity accelerator for longer duct distances
Product Documents
Frequently Asked Questions
Q: What is the free-air CFM rating of the 9525-50?
A: The 20" Axial AC High Output Metal Blower delivers 7,500 CFM in free air, 6,700 CFM through one 90° bend, and 6,130 CFM through two 90° bends.
Q: Can this blower be used for both intake and exhaust ventilation?
A: Yes. The interchangeable flange allows the unit to be configured for either intake (supplying fresh air) or exhaust (removing contaminated air) side mounting.
Q: What voltages does the 9525-50 support?
A: The blower operates on 115V–230V AC, 60 Hz, providing flexibility for different site power supplies.
Q: Is this blower certified for use in confined spaces?
A: The 9525-50 is UL Listed and certified to CSA Standard C22.2 No. 113 (Fans and Ventilators), supporting use in confined space ventilation applications in compliance with applicable safety standards.
Q: Is this blower suitable for hazardous (explosive) environments?
A: No. The 9525-50 is a standard AC metal axial blower and is not explosion-proof. For hazardous environments, Allegro offers separate explosion-proof models (e.g., 9525-50EX). A qualified safety specialist should evaluate any confined space prior to entry.
Q: How far back should the blower be set from a confined space opening?
A: Allegro recommends setting the blower back a minimum of five (5) feet from the opening when ventilating a manhole or tank. This helps prevent hazardous gases purged from the confined space from being drawn back into the blower intake and recirculated into the space.