Retrocommissioning

 

WHAT IS IT?

Also referred to as RCx, Retrocommissioning is the process ‘re-commissioning’ the building systems as they were at its conception.

RCx is a two-fold process
1) a study performed on your facility that reveals fixes, tweaks and upgrades for your currently installed mechanical, electrical and control systems.
2) implementing the strategies and recommendations in the study to reduce operating expenses and ongoing maintenance and replacement of systems.

 

CHALLENGE

Unfortunately some buildings, and most older buildings never underwent a commissioning process in the first place, meaning systems were not checked, optimized and verified to by operating at their peak efficiency, some not even running properly.  Even if your building was properly commissioned, building systems work themselves out of their design parameters and specs within a matter of a few years.
Also building management processes are sometimes not clearly defined or followed which can lead to inefficiencies and wasted energy and man-hours.

DEFICITS

Since there is such a large cost to operating refrigerated spaces, and there is a great deal of waste in most systems, businesses pay an excess of electricity to their provider year after year after year.  It is common for a refrigerated warehouse to being paying double the amount of annual energy costs than they could be.  Inefficient evaporator fan motors also cause extra wear and tear on compressors and condensing units, which increases life-cycle maintenance costs.  Lastly, a warehouse full of evaporator fans running at high speed all of the time causes a drastic increase in noise levels which not only reduce workplace safety, but decrease employee productivity and morale over time.

SOLUTION

Replace all inefficient evaporator fan motors with 2 speed or variable speed Electronically Commutated Direct Current motors.  Add a control device to each evaporator to control the fan motors in that evaporator.  Install a sensing unit to tell the controller when the compressor duty cycle is on and refrigerant is flowing through the evaporator so the new high efficiency fans run at high speed, and at low speed when the compressor duty cycle is off.

SEE IT WORK

PROCESS

Our proven turnkey process:

  • Collect existing motor data and electric bills from customer
  • Design an energy efficient motor and controls upgrade for the existing evaporators
  • Run energy calculations to identify the Investment, cost savings and Payback and create proposal
  • Work with utility provider engineers to verify savings and secure available utility incentives for project
  • Installation and on-site Project Management to oversee project, including pre and post data logging
  • Reconcile project to include data logging savings analysis, and available utility incentive

TAKE ACTION

To start, schedule a 30 minute discussion with one of our Energy Analysts to determine if what we do is a fit for your facility.  We require very little information to create a proposal that will include:

  • the Investment/Payback model
  • the amount of wasted energy
  • the annual cost savings
  • utility incentives that may be available

Click here to schedule.

Energy Conservation Measure

Details of Implementation

% of subsystem energy savings

1. Enable floating condensing pressure control

Using the lowest possible condensing pressure set point saves energy most of the time, but when it is hot enough outside that the wet bulb temperature gets close to the condensing temperature set point, the VFD fans ramp up in speed dramatically.

Saves 8% of Condensing operation energy use.

2. Condensor variable speed motors and controls

Implement controls and variable speed motors to stage the fans by running the most efficient condensers first, bring subsequent fans online as needed, and run all online condenser fans at the same variable speed needed to fulfill the condensing operation of the system.

Saves 6% of Condensing operation energy use.

3. Evaporator multi-speed EC motors and controls

Upgrade evaporator fan motors and add controls to allow the evaporator to run at a reduced speed when the compressor duty cycle is off which significantly reduces energy use and heat load into the box from inefficient motors running at high speed 24/7.

Saves 80% of Evaporator operation energy use.

Naturally, our initial focus is on the evaporator system, as we can achieve Paybacks of 18-24 months.

This brief video will show you exactly how the system work, and how significant energy and cost savings are derived.