Factory-Installed Partner
Factory-Installed APR Control:
MJC, Inc.
MJC, Inc., a factory-authorized equipment manufacturer and modifier, installed the Rawal APR Control in this unit. Here's what it does, why it's there, and how to adjust or service it.
UL Listed · 100,000+ valves installed since 1993
What is the APR Control?
The APR Control is a mechanical, external compressor unloader that adds continuous capacity modulation to DX air-conditioning systems. It lets the compressor run at reduced capacity instead of cycling on and off, matching cooling output to the actual load in the space. The result is better dehumidification, steadier temperatures, and lower energy use at part load, where systems spend 90%+ of their run hours.
Its suction pressure-activated design is fully mechanical, with nothing to program and no controller or software to maintain. Rawal Devices manufactures the APR Control exclusively; it is supplied through OEMs, distributors, and factory-authorized modifiers like MJC.
Why the APR Control was installed in this unit
- Improves comfort and dehumidification across changing loads
- Reduces compressor starts for less wear and longer service life
- Helps eliminate short-cycling service callbacks and downtime
- Lowers energy consumption during part-load operation
- Maintains stable temperatures and provides passive evaporator freeze protection in VAV, 100% outside-air, and high-ACH applications
Ideal applications
Commercial office buildings
K-12 schools and universities
Hospitals and healthcare buildings
Data centers, labs, and cleanrooms
Restaurants and kitchens
Mixed-use and high-humidity spaces
About MJC, Inc.
Based in Cartersville, Georgia and in operation since 1989, MJC, Inc. is an HVAC equipment manufacturer specializing in custom-engineered products, equipment modifications, and coating solutions for commercial and industrial applications, including factory-installed APR Controls.
