– HVLS Fans

Direct-Fired Industrial Air Handlers - 4000 Series

The RAPID® 4000-Series is a customizable ultra-efficient direct-fired heating, cooling and pressurization system. Available from 5,000-150,000 CFM.

RAPID® 4000-Series are extremely durable and long-lasting, creating Rapid’s reputation for industrial-grade quality and long lifespan.  Constructed with an external skin welded to an internal welded structural steel framework, energy efficient airfoil fans and heavy-duty fan bearings with an ABMA L-10 rated life of 100,000 hours, energy efficient & low maintenance direct-fired burner and manifold.

Direct Fired Make Up Air Unit


Links & Docs

Typical Installations

All models and air styles are available in upright and horizontal as well as indoor and outdoor configurations.

Indoor Make Up Air Unit
Roof Mounted
Commercial Rooftop Make Up Air
Suspended (Wall or Roof Inlet)
Horizontal on Legs (Indoor or Outdoor)
Direct Fired Make Up Air System
Upright Indoor
Upright Outdoor
Outdoor Make Up Air System


OA = Outside Air, DA = Discharge Air, RA = Return Air

Model Configurations

 The units are available in four different air styles- MUA (100% outside air with a fixed discharge air volume), FR (fixed 80% return air / 20% outside air with a fixed discharge air volume), AM (modulating return air / outside air with a fixed discharge air volume) and VAV (100% outside air with a variable discharge air volume). These four different air styles, along with the availability of evaporative cooling, mechanical cooling, post-cooling reheat and a wide variety of accessories, make these units extremely flexible and able to meet a wide variety of heating and cooling needs.