The Rawal Devices team welcomed this year’s attendees stopping in to learn more about two core offerings from the company, starting with the APR Control®.

“The APR Control is available for new and retrofit/service applications to provide continuous capacity modulation on all major HVAC manufacturers’ DX systems,” according to Rawal Devices vice president Amy Ruggiero. The company offers it in mechanical and electronic versions to meet cost and performance requirements of single- or multi-stage DX systems.

“As we often advise customers,” she said, “Chiller dreams on a DX budget … install Rawal.”

Rawal engineer Jason Santos noted that the APR Control is not hot gas bypass and thus is incapable of creating a false load on the evaporator. In more technical detail, he described that the APR Control is a continuous-capacity modulation device that externally unloads the compressor by diverting refrigerant from the outlet of the compressor back to the suction inlet. This increases efficiency in direct expansion (DX) HVAC systems and can reduce the compressor’s power consumption, in some cases by up to 20 percent, he said.

Another upside of implementing the APR Control, according to Santos, is reduced humidity levels. An environment more comfortable to occupants can allow room for thermostat settings to be higher, and lower energy consumption costs.

“Nearly every contractor or technician has experienced systems that short cycle or cannot maintain dehumidification and comfort levels because they are oversized,” Santos commented. “A service technician may find there are times when the air conditioning system is operating within manufacturer’s specifications, yet the customer still complains about comfort issues. The problem is that standard air conditioning systems do not have the ability to modulate capacity to meet ever-changing space demands. The issue is that staged compressors are either on or off (short-cycling).”

This short-cycling leads to excess humidity issues, where the APR Control is designed to serve as a simple, cost-effective solution that can help contractors to deliver comfort and retain satisfied customers who may be experiencing this issue.

Santos reports that the unit has done well when applied in schools, restaurants, convenience stores, and retail spaces. In addition, pharmaceutical production, food processing, and cleanrooms can benefit from this approach.

The possibilities for applications don’t stop there. Santos cited increasingly stringent energy codes and the cannabis growing industry as two more rapidly expanding applications opening more opportunities for the APR Control. He notes the unit does well in VAV and 100 percent outside air systems, too.



Rawal also showcased its APR-E Valve® at the booth this year. The product offers capacity modulation on any fixed compressor system to a precise discharge air setpoint. This valve is an electrically driven, electronically controlled external compressor unloader designed to provide modulation on any single or multi-stage DX system. The APR-E Valve can stand alone or easily integrate into an existing BAS/BMS for a new or retrofit application.

Santos reminded contractors to feel free to reach out and speak with someone on Rawal’s team of experts regarding either product or to answer particular questions.

“We would enjoy connecting contractors with one of our various whitepapers, webinars, and trainings,” he said, adding that professionals can look for Rawal’s upcoming series of emails with supporting materials on “how the APR Control offers a way to make commercial/industrial DX air conditioning systems compliant with changing energy codes.”