Chemical Resistant NFPA 496 UL Classified Building & Room Pressurization Units

Optional Features

In addition to various case styles and materials, unit sizes and area ratings, Bebco offers two vital options for our Model WDP and RDP Whisper Drive™ Building Pressurization Units.

Please consider these options carefully, to ensure our product will satisfy your application properly and perform in the best manner possible.

Bebco provides remote control inputs to ensure total compliance with your safety requirements and custom housing finishes to resist highly corrosive atmospheres or match stringent specifications!

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Bebco Model WPD & RDP Units may feature hard wire or intrinsically safe inputs to permit remote control of Whisper Drive™ Units upon emergency conditions. These options include an Emergency Shutdown to deactivate both fans and an Emergency Control Override to fully engage both fans.


This optional input is most often utilized to deactivate your Model WPD & RDP Whisper Drive™ Unit upon the suspicion or detection of combustible gases entering the fresh air intake stack, which if unchecked would introduce this danger to your room or building. To implement this option, the use of a combustible gas detector sensor, stack mounting bracket, combustible gas detection unit and power supply can be coupled with an emergency shutdown operator wired in series to the Whisper Drive™ Unit. Our fail-safe circuitry ensures that any cause, including a broken wire, gas detection or activation of the emergency shutdown operator will stop the Unit immediately, until safe conditions are restored.


This optional input is most often utilized in analyzer rooms or laboratories that contain a source of combustible gases, vapors or liquids. This input causes both fans of your Model WPD & RDP Whisper Drive™ Unit to operate at full speed upon the suspicion or detection of combustible gases being released into your room or building, which if unchecked would quickly create a growing danger. This option is implemented by using a combustible gas sensor in the room or building, a combustible gas detection unit and power supply and a hand-off-auto operator wired in series to the Whisper Drive™ Unit. Our fail-safe circuitry then provides immediate emergency ventilation, until safe conditions are restored.

Emergency Remote Controls
Emergency Shutdown & Override Inputs
Provides ability to deactivate the Unit or make both fans run at full speed!

Optional Remote Inputs


Provides protection against the introduction of Combustible Gas
through the fresh air intake stack or the internal release of Combustible
Gas within a room or building from analytical systems and laboratory hoods.


A: Hard Wired ESD & ECO Inputs

B: Intrinsically Safe ESD & ECO Inputs

C: Intrinsically Safe ESD Input

D: Intrinsically Safe ECO Input

E: Excluded

Optional Wiring Methods

Hard Wiring

Hard Wiring
this option requires the use of conduit, seals and wiring
or hazardous location rated cable

Intrinsically Safe:

Intrinsically Safe Wiring
this option allows the use of intrinsically
safe cable approved for the location

As a unique, advanced feature, Bebco Model WDP and RDP Whisper Drive™ Building Pressurization Units are available with Emergency Shutdown and Control Override Controls in hard-wired or intrinsically safe versions. When specified for WDP Units, an optional pre-wired junction box is added to simplify unit installation. When specified for Model RDP Units, hard wired terminals are provided in the remote-control station or a separate junction box with intrinsically safe barriers is supplied for installation in a location of your preference.

These inputs can be wired to emergency operators and combustible gas detectors to manually or automatically prevent or evacuate the entry or release of combustible vapors within your pressurized room or building. Bebco offers all of these devices as accessories to our Model WDP and RDP Units, and Bebco Sales Associates can also provide typical shutdown circuit wiring diagrams and support to guide you through the process of considering and selecting the best configuration of remote-control inputs and remote-control accessories to meet your safety requirements.

Bebco offers an option to finish your Model WDP or RDP Whisper Drive™ Unit Housing with a highly resilient urethane sprayed, epoxy powder coated or custom finish of your choice. Custom finishes can be applied using the brand, color and application method of your preference!

These options enhance the corrosion resistance of all units and greatly extend their service lifespans, permit you to satisfy a stringent paint specification, or match the finish and color of a building paint scheme.

Bebco provides flexible protection and finish customization to meet your unique requirements!

Standard & Custom Housing Finishes
Custom Paint Finish for all Housing Parts
Provides specification compliance or matching finishes when essential to your application!


Mild to Severely Corrosive Environments

Special Finish Requirements


U: White Urethane Sprayed Finish

P: White Epoxy Powder Coated Finish

C: Custom Finish*

* Custom Finish must be specified at time of order to indicate paint types and brands, custom colors and application methods, including powder coating.

Do you have a unique application that requires a custom finish or color? Bebco Model WDP & RDP Whisper Drive™ Housings are offered with a 3-6 mil thick white urethane standard finish or a custom finish based upon your specification of paint type, brand, color and application method.

Regardless of which option you select, standard or custom coatings are applied on all sides of all finished parts, which are then assembled after curing, so no metallic surface is uncoated, regardless of its interface with other metallic or non-metallic parts. Ask a Bebco Sales Associate for more information regarding this valuable optional feature!