Boilers & Water Heaters
Part 2: Improving Boiler Energy Efficiency with Retrocommissioning
Improving Boiler Energy Efficiency with Retrocommissioning
By James Piper, P.E. - November 2012 - HVAC
If the decision is to continue repairing the boiler or water heater, managers can undertake a retrocommissioning process to identify and address areas of energy inefficiency in the unit. The retrocommissioning process begins with a detailed review of the boiler or water heater, including data on equipment installed, connected loads, the critical nature of the loads, maintenance history, and operating performance.
Besides installation errors, operators might have made changes to the installation over the years. Of particular interest are changes they implemented to correct maintenance issues that are preventing the unit from operating as efficiently or effectively as intended.
Next, managers need to review maintenance records for the boiler and consider whether technicians have performed maintenance according to manufacturer recommendations or bypassed certain features to circumvent operational issues. They also need to determine whether the boiler has required more maintenance as it has aged, and they need to identify operational and maintenance issues.
Technicians need to check and test safety features to ensure proper operation. They also must measure the boiler's efficiency under different loads and verify the boiler's control system operates properly.
Once technicians have completed the test and managers have analyzed the results, managers will be able to identify the steps operators and technicians can take that will improve efficiency and performance. These steps can range from small changes in operating procedures to large overhauls of boiler components. Managers then will be able to estimate the cost and time needed to take these steps and evaluate their options.
The results of data-gathering and testing will be a road map managers can use to improve equipment operation. It will provide a list of recommended tasks, along with relative costs. Managers can implement some steps without interfering with the boiler's operation. Others will require careful scheduling because of the needed shutdown and interruption of service.
Retrocommissioning is not necessarily a one-time task. Managers must be ready to repeat the process to ensure the boiler or water heater continues to operate efficiently. The timing of the process will depend on the application, as well as the condition and size of the installation.
James Piper, P.E., is a national consultant based in Bowie, Md., with more than 25 years of experience with facilities maintenance and management issues.