18 February 2021
Andrew Gaskell, Chairman of the Chilled Beams and Ceilings Association, suggests we follow Australia’s lead when integrating HVAC systems into the design stage of buildings to improve energy efficiency.
On July 25 2019, the UK experienced its hottest day on record, peaking at 38.1˚C in Cambridge. Just a day before, CIBSE held a London seminar titled Avoiding overheating, during which Head of Research Anastasia Mylona and Technical Manager Julie Godefroy discussed revisions to Approved Documents F and L, as well as the causes and risks of overheating buildings.
Although many people may have enjoyed the hot weather, dehydration, breathing difficulties, heat exhaustion, and heatstroke are just some of the dangers that can put people’s lives at risk during periods of extremely high temperatures.
Poorly installed, maintained and controlled HVAC equipment and inadequate natural ventilation can drastically increase the chances of a building overheating, which can result in serious health concerns for the building’s occupants. The importance of ensuring a healthy indoor environment while remaining compliant with modern energy efficiency demands is an ongoing challenge for building managers.
Commercial buildings typically undergo many changes throughout their lives. Tenants will come and go, and every new occupant will have their own ideas on setup and working environment. The building owner or operator will need an HVAC system that can offer long term flexibility on top of long term energy savings. The way we approach building design in the UK makes it difficult to achieve optimum energy efficiency during a building’s lifetime. Our building regulations focus primarily on the design and technology that improves predicted building performance for purely compliance assessment instead of directly measurable improvements in performance in-use.
Different Down Under
We enjoy a great sporting rivalry with Australia, as demonstrated by the thrilling 2019 Ashes series. The series was tied, but away from sport, our Aussie friends are some way ahead of us when it comes to energy efficiency in buildings. Their ‘NABERS’ (National Australian Built Environment Rating System), introduced and implemented over the turn of the 21st century, is a performance-based rating system for buildings. A NABERS rating for a building is based on a methodical assessment of the actual environmental impact of operating it and has allowed buildings and workplaces in Australia to achieve impressive environmental savings that we should be examining and learning from. In particular, Australia’s method of incorporating the simulation of HVAC systems and controls at the design stage of a building would help our drive towards lower heating emissions.
It is always worth reminding ourselves that around 40% of global energy consumption is attributed to buildings, with cooling and heating alone contributing a significant portion of that. We can change that by adopting greater scrutiny of the HVAC system, which we currently lack a basic rating system for in the UK, where we have, for too long, designed our buildings to comply with regulations. This results in the performance gap between original design intent and the reality of how the building performs. In contrast, under the NABERS system, both landlords and tenants, as well as other invested parties, can use a base building rating to factor in-use energy performance into their decision making.
For commercial premises in the UK, landlords will generally provide a central HVAC service to their building. Still, the occupiers’ own HVAC systems are then more likely to be outsourced to the tenants themselves, who will also control their own building management system. With each tenant having their own HVAC system and facilities management team, it is very difficult for the landlord to maintain any real control over their building’s efficiency because they must keep the central heating system operating continuously.
In Australia, while tenants manage the fit-out of their HVAC systems, the landlord maintains oversight over the design and can refuse approval of the system if it is likely to affect their building’s base rating negatively.
Beams of efficiency
The diversity and flexibility of chilled beams make them an ideal HVAC solution for a more integrated approach to building design and function. Picking the cheapest system without taking running costs into account could end up proving extremely costly in the long-term.
A key attribute of chilled beam technology is an inherent efficiency that can help building operators to slash energy bills, delivering significant savings over an extended period.
Occupant comfort and energy efficiency do not have to be mutually exclusive. Therefore, the choice of an HVAC system should play a more prominent role in the design stage of a whole building instead of being considered separately. Modern commercial buildings require a modern approach to cooling, heating and ventilation, and multiservice chilled beams (MSCBs) are capable of providing a full range of services to meet specific user requirements. Also, chilled beams can work well alongside other energy-efficient technologies such as heat pumps to offer practical long-term heating and cooling solutions.