The route to decarbonisation for office buildings can seem daunting, but many London based businesses have taken a big step forward by adopting a new and innovative engineering approach. The key is reimagining the capabilities and the purpose of chillers, as Bill Watts, Max Fordham's Director of Decarbonisation explains.

Decarbonisation is fast becoming a top priority for businesses to meet net zero carbon targets and reduce operational costs. The 2050 net-zero strategy and corporate ESG targets on leased buildings are working to nudge owners and occupiers of commercial buildings to think about their decarbonisation roadmap. To achieve this, getting off gas is critical, but implementing it can be difficult to plan and budget for. Most offices in the City of London are cooled by chillers (large air conditioning units) and heated by gas. Both chillers and gas boilers are renewed periodically as part of a building’s normal maintenance programme, which is where the opportunity lies. There is an integrated, low-carbon heating solution – known as 4-pipe heat pump chillers - that can be installed when old chillers are replaced, enabling building owners to ditch their gas boilers and decarbonise in a cost-effective way by upgrading an existing system.

What's the engineering behind a 4-pipe heat pump chiller system? Chillers (and air conditioning units in general) remove heat from inside a building and dispose of it outside. Air source heat pumps transfer heat in the other direction and bring it indoors. However, a modern chiller can move heat in either direction and essentially perform the task of a heat pump. Offices are especially suited to these systems for several reasons. Heating and cooling is sometimes required at the same time in different areas of a building (i.e. cooling a server room while heating an open plan office space) and an intelligently configured system can use heat recovery to meet demands with maximum efficiency. Offices heated by fan coil units (capable of blowing cold or hot air) will also be typically ready to adapt, and many offices have surprisingly low heating demands due to all the other sources of heat in a building, namely people and computer equipment. 

It’s important to stress that changing the use of a system requires a good understanding of its configuration and controls, and getting this right is crucial to ensuring the overall system functions as intended. However, 4-pipe heat pump chiller systems are an established way to meet heating and cooling loads, and at Max Fordham we’ve been specifying these types of systems for many years. In the renewal of a 1950s office building at 11 Belgrave Road our MEP strategy focused on minimising carbon in operation and arming the building users with information and flexibility to aid this. 11 Belgrave Road is now net zero carbon in operation and the first project in the UK to achieve a NABERS UK 5.5* design-reviewed target rating for in-use energy efficiency. 

We have found that providing building performance evaluation and optimisation post-completion further minimises operational carbon emissions and maximises savings, to deliver low carbon buildings without compromising on comfort.