Hot Gas Bypass

MJC is a factory approved installer of the APR Rawal Valve.



See below information for the benefits and solutions the APR Rawal Valve can provide!

The APR Control Automatically Matches System Capacity to Changing Loads
Installing an APR Control is like giving your AC system a brain. This hot gas bypass continuously modulates system capacity, automatically matching it to reduced or changing loads. The APR Control responds quickly to changing load conditions by monitoring the heat content of return air and adjusting refrigerant flow.

As a result, it maintains the AC in dehumidifying mode while providing close temperature control. With reduced humidity levels, the space feels more comfortable to occupants, allowing higher thermostat settings and lower energy costs.

Improves System Performance, Reduces Service Costs
The APR Control:

  • Improves humidity control, reducing humidity levels without overcooling the space
  • Reduces compressor cycling, thereby reducing wear-and-tear on the compressor, energy costs, and repair costs
  • Prevents coil icing or liquid slugging, even if a filter is clogged or a belt is malfunctioning
  • Reduces system maintenance and repair costs, and eliminates repeated service calls for the same problem
  • Outperforms hot-gas bypass
  • Automatically compensates for inaccurate design data/assumptions or changes in load

Outperforms End-Type Controls
Because the APR control responds instantly to the heat content of return air, it outperforms end-type controls such as thermostats and humidistats.

Simplifies System Renovations
The APR Control has been successfully used to improve comfort and system performance in a wide range of renovation applications involving oversized RTUs, undersized ductwork, system expansions, and building layout/use changes that resulted in dramatic load shifts or widely varying loads.

Compensates for Efficiency Differences in Old and New Equipment
The APR Control effectively compensates for reduced suction pressures that result when new high efficiency systems (with oversized condenser units) are used with older lower efficiency evaporators.

Reduces Variability of Make-Up Air
In high-percentage make – up air systems (25% ~100%), cooling/dehumidifying loads can vary widely. By keeping the system online longer, the APR Control reduces the cycling caused by wide variations in the temperature and humidity of make-up air. In addition, by reducing the variation in make-up air, the APR Control improves compliance with ASHRAE ventilation standard 62-1989.

Reduces or Eliminates Reheat
The APR Control can also significantly reduce or, in some cases, eliminate reheat. Since reheat typically accounts for 30% ~ 50% of the operating cost of AC systems, the APR pays for itself in months.

Reduces the Cost of Piping and Ductwork in Multiple Evaporator Zone Systems
By permitting the control of individual fan coil evaporators using simple thermostatically-activated solenoid valves, the APR Control reduces ductwork and system installation costs. It provides superior performance even for zones that are remotely located, oddly shaped, or have widely varying load conditions. No complicated piping, control wiring, or expensive air-side controls are required. When sizing pipe for this type of installation, ASHRAE refrigerant piping protocol must be observed.

Approved for Use with New Environmentally Friendly Refrigerants
The new APR Control has been tested and approved for use with new R410-A environmentally

Hot Gas Bypass modifications

Hot Gas Bypass modifications