Re-Commissioning (Re-Cx) is for existing buildings and is the systematic process of determining actual performance, troubleshooting, and system tune-up. Focus is on comfort, energy, indoor environmental quality (IEQ), long life for equipment and training for staff. Your utility may have rebate programs to help fund the Re-Cx study. Procedures and activities for re-commissioning differ for each building, but some of the common ones are highlighted below:
- Just like your car, a building needs a tune-up by an expert every so often even though you feel it is OK. Current control strategies can be enhanced and new control strategies can be implemented.
- A thorough investigation of the building purpose and the HVAC & lighting systems helps everyone on the Re-Cx team understand what there is to work with. This includes benchmarking your energy use and system capacities.
- Working with the building management and operating staff, we can look at newer and innovative ways to make your building occupants more comfortable while saving energy.
- Re-Cx is not putting your building back the way it was when opened, but working with your current needs and building systems to enhance the operation and provide tools to the staff to continue the gains on an on-going basis.
- Building performance may have been adequate when new, but over time may have degraded for a number of reasons. Specified or original system performance data may not exist, and/or building function or usage may have changed.
- Some typical measures found and implemented have saved many building considerable energy dollars
- Optimal start of heating and cooling systems – most BAS have this built-in but it is not active
- Reduce outside air quantities based on current population – most buildings have less people
- Reset strategies based on actual needs – only having temperatures & pressures req’d. at the time
- Optimal stop – allowing the heating or cooling systems to “coast” near the end of the day
- Terminal unit balancing – check CFM & temperature needs based on current use
- Turning equipment off when not needed – understanding your building operation 24/7 not just when “occupied” can save considerable energy dollars
- Every building will have a combination of typical and unique operational opportunities – we allow the building to “tell us where to look” for opportunities to save energy
The Re-Cx process is the “best bang for your investment buck”. On average, there is an energy payback of less than one year for the measures identified and implemented.