Maximize Comfort & Efficiency with Precision Temperature Control of the Electronic APR-E™ Valve!
Since 1993, Rawal Devices has successfully manufactured and sold the mechanical APR Control valve for continuous capacity modulation on new or existing, in-place HVAC systems.
In 2009, Rawal introduced the electronic APR-E valve for continuous capacity modulation that could be installed in your new or existing HVAC system, while also integrating into your BAS or controls system as a precision temperature controller.
What is the APR-E™ Valve?
The APR-E Valve is an electrically driven, electronically controlled motorized external compressor unloader that provides precise temperature control on any single or multi stage DX HVAC system.
It is popularly used as a discharge air controller on DX systems. The APR-E modulates the flow of refrigerant to the compressor, allowing the system to run longer at part-load conditions, which can save energy and improve system efficiency.
The APR-E can be used in VAV systems, make-up/dedicated outside air systems, and chillers. We’ve found the APR-E has most commonly been installed for applications in labs, cleanrooms, hospitals, and manufacturing facilities – just to name a few specific applications.
How does the APR-E Valve work?
The APR-E Valve modulates refrigerant flow based on an electronic signal from either a stand-alone control board or an integrated control board that responds to an existing building automation system (BAS). Based on your control sequence, the control boards send a signal to the valve, which opens or closes the APR-E Valve to modulate the flow of refrigerant entering the evaporator.
The APR-E diverts the discharge gas into the suction line before the compressor. Thus, modulating the cooling capacity of the evaporator.
As the discharge air temperature falls below setpoint, the APR-E can be controlled to open and begin modulating. This action decreases the amount of refrigerant to the evaporator, resulting in a higher discharge air temperature off the coil.
Conversely, as the discharge air temperature rises above setpoint, the APR-E can be controlled to modulate towards the closed position. Now increasing the amount of refrigerant to the evaporator, decreasing the discharge air temperature off the coil.
The APR-E™ Valve offers two control options to suit your application:
External Control Board (Integrates with existing BAS):
Need to integrate your APR-E™ valve with your building automation system? Choose the External Control Board for seamless communication and centralized control.
- Accepts analog 0-10 VDC or 4-20 mA signals from your BAS.
- Provides flexibility for integration with complex control systems.
Stand-Alone Controller (Potentiometer):
Looking for a simple, hassle-free solution? The Stand-Alone Controller automatically adjusts the valve based on temperature, requiring minimal setup and maintenance.
- Need to manually dial in…
- Easy to install and configure.
- Modulates the APR-E Valve based on discharge air temperature.
- Ideal for standalone applications or simpler systems.
Both APR-E control board options deliver exceptional precision, maintaining discharge air temperature within +/- 1°F of the setpoint throughout the valve’s modulation range.
Benefits of the APR-E Valve
Get the performance of a chilled water system while on a DX budget! No matter your needs, the APR-E™ valve delivers unmatched precision and performance.
- Superior Performance: Improve system performance and efficiency with precision discharge air control within +/- 1°F deviation from setpoint.
- Greater Energy Savings: Utilizing supply air temperature reset control strategies with the APR-E, a higher set point can save as much as 10% percent on your power.
- Initial Cost Savings: Obtain the versatility of a chilled water system while still remaining budget friendly.
- Maintain Compliance in Critical Applications: Meet energy code demands and maintain control to Dew Point for temperature stability in critical applications (labs, cleanrooms, etc.).
Similar to the mechanical APR Control, the electronic APR-E Valve also provides:
- Improved occupant comfort
- Extended system lifespan from reduced wear and tear on the compressor
- Ease of installation and configuration
- AND can also be used in a variety of applications
For Building Owners and Facility Managers:
The APR-E™ Valve is a smart investment that improves occupant comfort, reduces energy bills, and prolongs the life of your HVAC system. It’s a simple upgrade with significant long-term benefits.
For HVAC Professionals:
The APR-E™ Valve is a versatile solution that simplifies system design and installation. Its precise temperature control capabilities make it ideal for a wide range of applications, from VAV systems to cleanrooms.
Common Applications for the APR-E Valve
- VAV systems
- Make-up/dedicated outside air systems
- Chillers
- Labs & Cleanrooms
- Hospitals & Surgical suites
- Manufacturing facilities
- Indoor agriculture & grow rooms
APR-E Success Story:
Utilizing the APR-E Valve in an ASHRAE Cleanroom
ASHRAE, a global leader in HVAC&R standards and research, partnered with Rawal Devices to test innovative energy-saving strategies in a controlled cleanroom environment.
The goal? To demonstrate the effectiveness of the APR-E Valve in maintaining precise temperature control, even with fluctuating airflow demands. The results were impressive, showcasing the potential of this technology to revolutionize cleanroom HVAC design.
Read more about the ASHRAE Research Project here!
How is the APR-E Valve Installed?
The APR-E Valve is installed in the same way as our mechanical APR Control. It’s installed inside the compressor compartment of the condensing unit, with the connections made as shown in our instructional video:
How to Install the Rawal APR Control Valve on a DX HVAC System
The only difference in the installation process is that an experienced technician or controls specialist is needed to set up the control board for the APR-E. You’ll find detailed instructions and recommended control sequences in our Installation and Operation Manuals (IOMs):
If you have any further questions about the installation process, don’t hesitate to contact our support team!
How to Order the APR-E Valve
The APR-E Valve is available from Rawal Devices. If you have an application you are thinking about using the APR-E Valve for precise temperature control, please call and speak to our Senior Technical Engineer to discuss.
As always, to order, please contact Rawal Devices at 1-800-727-6447 or email us at sales@rawal.com.
Conclusion
The APR-E Valve is a versatile and energy-efficient valve that can be used in a variety of applications. It can save energy, improve system efficiency, and reduce wear and tear on the compressor. If you are looking for a way to improve the performance of your HVAC system, the APR-E Valve is a great option.
Case Studies
Resetting the discharge air temperature for development of ashrae cleanroom and energy saving standards
Angiotech electronic valve test / performance
