Tempest MVU Mobile Ventilation Unit: 130,000–150,000 CFM Truck-Mounted Apparatus for Large-Scale Fire and Industrial Ventilation

A working structure fire inside a 400,000-square-foot distribution warehouse does not respond to a pair of portable electric fans positioned at the doorway. Neither does a smoke-logged highway tunnel, a deep substation vault, or a multi-story parking structure with a fully involved vehicle fire on level three. The airflow math simply does not work at the portable fan scale — and every minute of delayed ventilation is another minute your crews are operating blind in IDLH conditions. The Tempest MVU® was engineered specifically for that moment: when nothing less than 130,000 to 150,000 CFM of forced air will do the job, and when that air needs to arrive mounted on an apparatus that drives to the scene under its own power.

What is the Tempest MVU Mobile Ventilation Unit and how does it differ from portable ventilators?

The Tempest MVU® (Mobile Ventilation Unit) is a truck-mounted, hydraulically driven axial ventilator available in two configurations: the MVU 48 at 130,000 CFM and the MVU 60 at 150,000 CFM. It is not a portable or semi-portable fan — it is a dedicated apparatus that mounts on a truck, trailer, or skid and drives to the incident.

Portable positive-pressure ventilation fans typically deliver between 10,000 and 30,000 CFM at best. The MVU 60’s 150,000 CFM output represents roughly five to fifteen times that airflow capacity, delivered through a 60-inch shroud at air velocities between 78 and 100 MPH. The MVU 48 moves 130,000 CFM through a 48-inch shroud at 78 to 94 MPH. That scale of airflow is what makes large-structure and subsurface ventilation operationally feasible rather than aspirational.

What engine powers the Tempest MVU and how long can it run on a single fuel load?

The MVU® is powered by a 133 HP (99 kW) diesel engine available in either a Cummins Diesel or Caterpillar configuration. The 55-gallon (208-liter) fuel tank provides approximately seven hours of continuous operating time per fill — a runtime that covers the overwhelming majority of extended structure fire, hazmat, and industrial emergency incidents without refueling.

Tempest rates the drivetrain for 24-hours-per-day, 7-days-per-week service with minimum maintenance requirements. Both Cummins and Caterpillar are industrial-tier diesel platforms with established service networks across North America, which simplifies long-term maintenance logistics for fleet operators. The 133 HP output feeds a full hydraulic power plant rather than a direct mechanical drive, meaning engine load is distributed through the hydraulic circuit rather than concentrated at a single driveshaft coupling.

How does the patented hydraulic drive system control the MVU ventilator, tilt, and scissor lift?

The MVU® uses a patented full hydraulic system that simultaneously drives the ventilator fan, the tilt mechanism, and the optional scissor lift from a single hydraulic power plant. This means all three functions share one fluid circuit rather than requiring separate electric actuators, manual cranks, or separate auxiliary engines.

In practical field operation, hydraulic control removes the failure modes associated with electric actuators in high-heat, high-humidity incident environments. Hydraulic circuits are pressure-tolerant, mechanically robust, and do not require the same wiring protection and weatherproofing that electric drive systems demand. The scissor lift function, offered as an optional feature, allows the operator to raise the fan shroud to match the geometry of a large opening such as an overhead door, aircraft hangar bay, or tunnel portal. The 360-degree rotation option adds directional control without repositioning the apparatus.

What is the axial ventilator design on the MVU and why does blade count and inlet geometry matter?

The MVU® uses a patented axial ventilator design featuring seven aluminum impeller blades with a clear, unobstructed inlet. Both the MVU 48 and MVU 60 share the seven-blade aluminum configuration and a maximum impeller speed of 1,160 RPM. Axial fans move air along the axis of rotation, making them efficient at generating high-volume, directional airflow at relatively low static pressure — the correct match for open-structure ventilation work.

The unobstructed inlet is a meaningful design decision. Hub-mounted motor assemblies and central obstructions at the fan inlet create turbulence in the inflow stream that reduces effective airflow and efficiency. By routing the hydraulic drive to the impeller without placing hardware at the inlet centerline, Tempest preserves the full swept area of the 48-inch or 60-inch shroud for clean axial intake. Aluminum blades balance corrosion resistance and weight at the 1,160 RPM operating speed, avoiding the fatigue concerns associated with heavier ferrous blade sets in long-duration continuous service. The Air Movement and Control Association (AMCA) airflow testing standards provide the accepted methodology for verifying rated CFM output on industrial axial fans of this class.

MVU 48 vs MVU 60: which configuration is right for the application?

The MVU 48 delivers 130,000 CFM through a 48-inch (1.2 m) shroud at 78 to 94 MPH, with a total apparatus weight of 8,800 lbs (4,000 kg) and overall dimensions of 177 inches long by 75 inches wide by 95 inches tall. The MVU 60 delivers 150,000 CFM through a 60-inch (1.5 m) shroud at 78 to 100 MPH, with a total weight of 13,200 lbs (6,000 kg) and overall dimensions of 197 inches long by 95 inches wide by 107 inches tall.

The 4,400 lb weight difference between the two models is the primary selection variable for departments operating within gross vehicle weight rating constraints on existing apparatus. The MVU 48 is the lighter, more compact platform while still exceeding the airflow capacity of virtually every competitive semi-portable unit. The MVU 60 is the correct specification for the largest-footprint applications — major warehouse incidents, aircraft hangars, long tunnel segments — where maximum CFM output is the governing requirement and vehicle weight capacity permits the larger unit.

What mount configurations and custom options are available for the Tempest MVU?

The MVU® is available in truck-mounted, trailer-mounted, and skid-mounted configurations. No special rigging or dedicated storage infrastructure is required beyond the host apparatus. Trailer mounting allows the unit to be towed by existing fleet vehicles without dedicating a chassis to the ventilator function. Skid mounting serves fixed-facility and industrial applications where the unit is positioned at a permanent installation point.

Custom options include the scissor lift for variable height positioning, 360-degree rotation for directional control, and a high-volume water misting system. The water misting option is relevant for hazardous material suppression assist, dust suppression in industrial environments, and heat reduction at the fan shroud discharge during extended high-temperature operations. Each MVU® is hand-built to customer specification at Tempest’s facility at 4708 N. Blythe Avenue in Fresno, California, making build-to-order customization standard rather than exceptional. You can review Tempest’s official MVU product specifications and configuration options directly from the manufacturer.

Where is the Tempest MVU deployed and what ventilation applications does it serve?

The MVU® is deployed in fire service, hazmat, and industrial emergency applications where portable fans cannot generate sufficient airflow to clear a structure or confined space within operational time constraints. The scale of 130,000 to 150,000 CFM addresses large industrial facilities, warehouses, tunnels, and major structural incidents as the primary use cases.

Fire departments and industrial emergency response teams source the MVU® through distributors who specialize in apparatus-mounted fire and rescue equipment. For departments building out a complete ventilation capability across portable, semi-portable, and mobile apparatus-mounted units, the MVU® occupies the top tier of the Tempest lineup. Related Tempest ventilation and fire equipment is available through PE Energy’s catalog, including Tempest Fire and Industrial products, the broader ventilation equipment category, and supporting fire and rescue equipment lines. Departments evaluating mobile ventilation apparatus should also review the full Tempest brand product range at PE Energy for complementary fan and ventilation products. Additional fire apparatus equipment and accessories are cataloged under apparatus-mounted equipment for departments outfitting complete response vehicles.

When is the Tempest MVU the right specification and when is it not?

The MVU® is the correct specification when the incident structure exceeds what portable positive-pressure ventilation fans can realistically clear, when operating time requirements extend beyond what battery or small-engine portable fans can sustain, and when the department or industrial facility can dedicate a truck, trailer, or skid platform to the unit.

It is not the correct specification for departments whose primary ventilation need is residential structure fires where a standard PPV fan is aerodynamically appropriate and a 13,200-lb apparatus-mounted unit would be operationally excessive. It is also not suited to applications requiring frequent manual repositioning without a host vehicle, confined-space entry ventilation requiring ducted discharge into a small-diameter access point, or environments where the 8,800 to 13,200 lb weight of the apparatus exceeds the load capacity of the access route. For those applications, Tempest’s portable and semi-portable fan lineup provides the correct scale of airflow in a repositionable format. The MVU® exists for the incidents where nothing smaller is adequate.

The Tempest MVU® represents a deliberate engineering commitment to the large-scale end of the fire and industrial ventilation problem: a 133 HP hydraulic-drive axial ventilator, hand-built in Fresno, California, rated for continuous duty, and sized to move air through structures that defeat everything else in the portable fan class. When the incident demands 130,000 to 150,000 CFM and seven hours of uninterrupted runtime, the MVU® is the tool that was built for exactly that requirement.

Tempest Fire & Industrial

MVU® Mobile Ventilation Unit

130,000–150,000 CFM | Hydraulic Drive | Cummins & Cat Diesel | Made in USA

Overview

The Tempest MVU® (Mobile Ventilation Unit) is the most powerful ventilator in the Tempest lineup — the original massive mobile ventilator engineered to conquer the toughest ventilation challenges. Available in 48-inch (130,000 CFM) and 60-inch (150,000 CFM) configurations, the MVU® delivers airflow unlike anything in the portable or semi-portable fan class.

Driven by a full hydraulic system powering the ventilator, tilt, and scissor lift, the MVU® mounts on truck, trailer, or skid. Powered by a 133 HP Cummins Diesel or Caterpillar engine with a 55-gallon fuel tank — 7 hours of operating time per fill. Custom-built in the USA and designed to remain in active service for decades.

Manufacturer: Tempest — 4708 N. Blythe Avenue, Fresno, California 93722 USA — tempest.us.com