Commissioning – from seasonal to continuous

The commissioning of buildings and building services is one of those tasks that’s often time squeezed as projects come to an end.

But whether it’s a new-build or a refurbishment, commissioning the whole building and its HVAC systems is critical to long-term energy-efficient performance.

In fact, CIBSE notes that: “In a world of accelerating technological advancement, increasing building complexity, tightening regulatory constraints, growing consumer demand for quality, surging environmental consciousness, and an urgent need to de-carbonise buildings, commissioning is one of the most important ways to achieve these outcomes.”

Correct standards

The issue of complexity is significant because increasingly, we see specialists brought in to commission air conditioning systems, for example, while others will be checking on hydronics and BEMS, among others.

Moreover, the use of specialists for commissioning equipment is far more common today.

We see the increased requirement for certification for operatives, for example, REFCOM qualifications for handling refrigerants in air conditioning systems.

But commissioning is not a one-off event (or, at least, it shouldn’t be).

Standards such as BREEAM and LEED highlight the importance of seasonal commissioning – and these are increasingly important to building owners looking to demonstrate commitments to carbon reduction.

Full range of operation

The concept of seasonal commissioning recognises that some aspects of the systems need to be commissioned when the external temperatures and indoor occupancy patterns are close to ‘peak conditions’.

This ensures the equipment is energy efficient across its full range of operation.

Usually, seasonal commissioning takes place within 12 months of building occupation (or completion of the refurbishment project).

This may be enough time to gather data on occupation, for example, but what if the building is a flexible office space with many short-term clients using the building over extended hours?

Just what is ‘peak’?

One of the challenges today is knowing what constitutes ‘peak conditions’.

The office market, in particular, has undergone such transformational shifts in usage patterns that building managers are still coming to terms with what peak and off-peak look like for their HVAC (and other) systems.

In this case, it may be helpful to adopt a more continuous approach to commissioning, especially around equipment such as chillers, as these can significantly impact energy use and occupant comfort.

Continuous commissioning

There are several benefits to going beyond the old concept of ‘seasonal’ commissioning.

Not least is that continuous commissioning can provide minor corrections in performance every few months.

This not only supports energy-efficient operation, but in the case of chillers, for example, it means that small issues can be addressed before they become big problems – and breakdowns.

Keeping it simple

Continuous commissioning need not be complex or time-consuming for the facilities team.

With remote monitoring via cloud-based controls, the process can be largely automated and placed in the hands of an off-site team of experts.

The by-product of monitoring in this way is data collection, providing the building management team with valuable insights into cooling system performance over time – a handy resource when usage patterns are less predictable.

The continuous approach can be used on existing buildings as well as new-builds.

In addition, with the growing focus of regulation on long-term energy use and operational carbon (such as the tightening requirements on MEES), continuous commissioning of HVAC systems can help to monitor – and manage – the energy use of equipment.

We’re also seeing the adoption of the NABERS energy rating in the UK office market.

This Australian-based rating system focuses on the actual energy performance of a building (rather than predicted, as with the EPC).

Continuous commissioning can be an invaluable tool for building owners and occupants working to meet NABERS standards, ensuring equipment is optimised for efficiency in the long term.

Dave Archer is National M&E Manager