GNcareers, from Gulf News

Energy efficiency through BMS

Building management systems can reduce annual energy consumption by up to 40 per cent, but most are currently nonfunctional or underutilisedSougata Nandi

A couple of years ago, in a meeting with officials of a municipality in the UAE, I was told that 90 per cent of the building management systems (BMS) in the UAE are either non-functional or unutilised. Coming from the number one and number two representatives of the municipality, this statistic has to be highly reliable.

On the other hand, in my numerous interactions with owners of over 500 buildings in the UAE for projects related to energy efficiency, I have been routinely told, “We have BMS, and thus we are already energy-efficient.”

It’s just like a car

Between these contrasting claims hangs the tale of energy efficiency through BMS and a huge latent opportunity to rapidly reduce UAE’s carbon footprint. Much in the same way as simply owning an automobile does not ensure one is automatically transported from point A to B, having a BMS need not ensure a building is being operated in an energy-efficient manner.

One has to drive the automobile, while following traffic rules and controlling the mechanism of the vehicle, in order to move from point A to B in a safe, secure and efficient manner. Additionally, one also needs to carry out periodic maintenance to extract optimum service and longevity of the automobile. BMS is no different. Like a vehicle, BMS needs to be operated as per its guidelines, components need to be maintained (and replaced) periodically, goals need to be set and performance reviewed for necessary corrective actions.

Driving characteristics have to adapt to changing road conditions and traffic rules. Likewise, a BMS’ operation has to adapt to weather conditions, indoor environmental quality guidelines and building occupancy. Fundamentally, a building owner also needs to ensure that the BMS has the right specifications for the expected performance, as far as energy consumption of the building is concerned, in an energy-efficient manner.

AC is key

There is currently a significant gap between having BMS and being energy- efficient. Not unlike so many other energy-efficient technologies, BMS requires heavy investment, but it remains largely untapped and underutilised. Buildings with installed BMS are typically large (at least 50,000 sqft of gross floor area) with central air-conditioning systems. The first and foremost dichotomy is that the main energy-consuming system — the heating, ventilation and air conditioning (HVAC) — is rarely operated through the BMS, having its own chiller plant management system. So, while the air-side HVAC equipment is being operated through the BMS, the water-side equipment is being operated through a separate automation system.

The second dichotomy is that while building owners typically have a maintenance contract for BMS, there is rarely a BMS operating contract in place. So while the BMS may be serviced periodically as per the terms of the maintenance contract and failed parts replaced, no one has actual responsibility of operating the entire automation system.

Who then ensures that the BMS is not only functional but delivers on its promise of making the building’s energy consumption as low as possible?

Capex vs opex

The biggest polarity is the fact that building owners are typically investing high capex (more than Dh100,000) to install BMS, continue spending good amount of opex (more than Dh10,000) every year for maintenance, yet have no one actually operating the BMS to extract the best performance, which in most cases it is quite capable of delivering.

In a worst-case scenario, the building owner has a BMS operator who is neither trained in energy efficiency nor given responsibility of reducing the building’s energy consumption.

A chance to save big

What is the economic scale of this latent opportunity? Based on actual energy efficiency projects in the UAE across a variety of buildings with different types of BMS in various states of underuse, one can safely say that once its BMS is properly operating, a building can reduce its annual energy consumption by anywhere between 10 and 40 per cent.

The exact reduction will obviously depend on the extent to which the BMS is currently being unutilised relative to the expertise of the energy efficiency specialist who is engaged. The more actively a building’s HVAC equipment is managed vis-à- vis the weather, indoor
environment quality requirements and occupancy of the building, the higher the savings accrued.

The functional nature of a building also dictates the extent of potential energy savings. For example, those relatively less occupied for many hours of the day, such as government offices, schools and residential towers, are likely to generate higher savings, while those in the retail, health-care and hospitality sectors may not enjoy similar reductions in energy bill through this mechanism. Quite importantly, such programmes need only about a couple of weeks to activate, unlike other energy-efficiency projects.

A caveat is that such savings will not accrue in buildings that are poorly designed for healthy indoor environmental quality. For such buildings, proper management of the building’s equipment may increase overall energy consumption.

Last but not least, the cost to achieve such range of savings has been seen to be quite nominal, with a payback period generally less than 12 months.

However, there is an ongoing opex that is required  for the necessary oversight of the energy efficiency programme. This is usually dictated by economies of scale and isn’t a deal breaker in the overall scheme of things.

Source: Property Weekly.