- De-scale the boilers and clean the flues
Boilers with scale/sludge build-up will waste energy through reduced heat transfer efficiency so it’s important to check for correct chemical dosing and for leaks that may result in untreated water continuously refilling the system. This ‘make up’ water increases scaling and reduces the overall system temperature, thus wasting energy. Flues should also be cleaned regularly; dirty boiler flue-ways can decrease boiler efficiency by more than 10%.
- Check boilers are correctly designed for the application
Boiler plant should be correctly designed and commissioned for the application with close attention paid to service reports and combustion efficiency – re-commissioning to adjust fuel/air ratio if necessary. When boiler plant is replaced, its efficiency may be affected by the existing distribution system and re-commissioning should take account of this.
- Check for conflicts between heating and cooling
It’s surprising how often poor space temperature control results in a space being heated and cooled at the same time. HVAC systems should be integrated so they work in harmony and avoid these conflicts.
- Assess occupants’ behaviour
Actions by a building’s occupants, such as changing room thermostats and opening windows, can have a serious impact on boiler/ system efficiency. Sometimes, building managers may override the normal programme for a special event, such as a parents’ evening at a school, and forget to re-set the controls afterwards. Regular evaluation of such behaviours will prevent these actions going unnoticed for extended periods.
- Understand the energy consumption
Main billing meters will not identify the energy consumption of individual items of plant so sub-metering is required to properly understand energy consumption at this level and measure the benefits of energy improvement initiatives. Any analysis of energy consumption needs to be degree-day-corrected to include the impacts of weather conditions, as well as taking account of other variables such as back-washing of swimming pools etc.