Introducing additional measures to fine-tune boiler performance, over and above those achieved by a BMS, can yield as much as 25% extra energy savings.
Sabien Technology the manufacturer of Fireye M2G has experienced over 70 projects in the last five years, showing unequivocally that the standard configuration for a building management system (BMS) or building energy management system (BEMS) does not address the issue of standby cycling
Unsurprisingly, many people expect that their BMS or BEMS will take care of boiler standby cycling, where the boiler fires to compensate for standing heat losses, resulting in unnecessary fuel consumption. The reality, however, is that the key role of a BMS is to optimize the whole building through the building services systems it controls. This is achieved by ‘looking at’ each system as a whole rather than the performance of the individual plant items. In the case of boilers, a BMS or BEMS monitors and responds to blended supply and return temperatures from all the boilers.
The fact that the BMS doesn’t ‘see’ this is also why many building operators are unaware that standby cycling is occurring – and it’s the reason why standby cycling isn’t included amongst the standard control strategies that are included in the majority of BMSs.
This was the situation at the headquarters of facilities management provider Serco, where the M2G boiler load controller was used to address standby cycling issues. “Many people think building energy management systems can control every aspect of a boiler’s operation but this is not the case. The M2G interfaced very smoothly with our BEMS and the two systems now compliment each other to maximize energy savings” explained Alan Taylor, Serco’s Technical Manager for Government Integrated Services.
Of course, it is technically possible to re-program a BMS to include standby cycling, but this is a time-consuming process that eats up expensive programmer time. It also necessitates additional sensors and, quite possibly, upgrading of the boiler room controllers.
In fact, when Jones Lang LaSalle (JLL) discovered standby cycling problems at some of their customers’ premises, re-programming the BMS was their initial consideration. Mark Bottriell, JLL’s Portfolio Energy Manager for Europe, Middle East and Africa explained: “In one case the BMS is very sophisticated and it would have been technically possible to have a special program written to control the standby cycling, but it was more time-effective to use an off-the-shelf product, which has potential to integrate fully with the existing BMS, particularly when contemplating new programming requirements.”
So if the cost of re-programming the BMS is prohibitive, it makes sense to use a retrofit solution that will deal with standby cycling and work with the BMS and other controls. Using validation techniques that have been independently verified, the M2G has been proven to provide typical fuel savings of between 10% and 25%, with payback periods consistently delivered under 2 years.