Retrofitting Commercial Buildings to Achieve Net Zero

Interview with Peter Ingram – RDM UK Head of Sales BEMS

The UK’s built environment is responsible for 25% of the country’s greenhouse gas emissions. While new buildings are built to higher energy efficiency standards, it is important to also focus on existing buildings to achieve net zero by 2050 since 80% of the buildings that will be standing in 2050 have already been built.

Various options are available to increase the energy efficiency of existing buildings such as replacing old windows, applying circular economy strategies to building waste materials, installing more efficient HVAC systems, and optimising building control strategies.

We spoke to Peter Ingram, UK Head of Sales (BEMS) at RDM, about retrofitting HVAC and building controls systems. He provided insights into the benefits of retrofits, considerations before starting the project, and energy savings that others have achieved.  

“Most existing buildings will have some form of Building Energy Management System (BEMS) or automation. However, BEMS installations have only relatively recently been given full reach and control,” Mr. Ingram explains. “Quite often, buildings have a boiler system for winter and water heating, and air conditioning for summer cooling.

“But these systems are not linked in any way. It is not unheard-of for the heating to be on at the same time as the air conditioning, both systems ‘fighting’ each other, and using excessive amounts of energy in the process.”

Retrofitting a BEMS allows to improve the management of both systems. “It’s easy to install a supervisory BEMS with a direct link to each system,” Mr. Ingram states. “This ensures that each system is only used when needed. 

“And simultaneous heating and cooling might be needed. For example, cooling might be needed for the south-facing side of the building while the north side needs heating.

“Retrofitting a correctly designed and installed BEMS with optimisation and compensation routines allows controlling on-off times and even the temperature of circulating water. This controls the energy use which lowers energy bills and the CO₂ footprint.”

BEMS automation and integration capabilities increase efficiency

The advantages of new BEMS go beyond regulating heating and cooling. The automation and interlinking capabilities of BEMS help facility managers prevent energy waste and move the building closer to achieving a net zero emissions status.

“A modern BEMS system such as RDM’s can link to many other electrical and mechanical systems such as building and car park lighting. It can be programmed to turn on the lights a few minutes before opening time and off again when they are not needed. The system ensures the building lights are only on when required for occupation or security and it doesn’t rely on someone remembering to switch off the lights.”

Additionally, electric, water and gas meters, air handling systems, occupation sensors, window sensors, and more can be linked to a central BEMS. This offers the building owner and their facility management provider much better visibility of the various connected systems all in one place. It also allows changes to be made remotely, at any time, on all sites, simultaneously.

“Take the recent additional bank holidays for example,” Mr. Ingram expands. “Companies with an RDM BEMS were able to alter the opening hours of all affected sites with just a few clicks via their remote monitoring platform ActiveFM. They didn’t need to visit all their locations to adjust timers onsite, they simply adjusted all of them remotely at the same time.”

Considerations before retrofitting HVAC and BEMS

If a business or facility management decides to retrofit HVAC systems and BEMS it is important to know what systems are already in place if they are well maintained.

“There are a few questions that are worth considering before deciding on a retrofit strategy,” Mr. Ingram highlights. “Is there any form of centralised control, or are all systems still separate? If a control system is already in place, is it up-to-date and operating well? What is it connected to? Who maintains it? Who is responsible for ensuring it is working well and as efficiently as it should? A trusted controls partner or facility management provider can help address these questions.

“If an existing system is more than a few years old, and especially if it has not been serviced regularly, then it might be worth upgrading to a newer system, as there have been many advances in BEMS over the years.

“Once it has been worked out what is already in place, then it is a matter of looking at the costs versus benefits of different refurbishment options to calculate return on investment.

“Older BEMS should be replaced to achieve the most efficient control of HVAC systems. RDM is well placed to provide not only superb control but also highly cost-effective refits.

“This is for many reasons, but to give just one, RDM’s BEMS controllers can connect to a huge number of different temperature sensors from various manufacturers. Replacing the controller does not require all the wiring to be replaced which saves time and money and it is ‘greener’ as it doesn’t create unnecessary waste.

“Quite often, the return can be very swift, and deliver huge savings. For example, a recent installation of an RDM BEMS in Bulmershe School in Wokingham has delivered 49% energy savings and a five-month return on investment. The existing controls in the school were poorly maintained, leading to very poor control of energy use. They were removed and replaced with RDM controls utilising improved optimum start/stop algorithms, alongside demand-based temperature control and vastly improved zone control.”  

Considerations during the installation phase.

Once it has been decided which mechanical and electrical systems should be controlled and monitored by BEMS, there are a few things to consider during the installation phase.

Mr. Ingram suggests asking a series of questions to establish how to install and deliver the new BEMS most economically: “What wiring can be re-used? What needs to be replaced, or augmented? Who will be responsible for operating the BEMS on-site? Do they need a dedicated screen or is a remote or local PC connection sufficient? Who will receive the alarms and how will they be handled?”

Ensuring the new BEMS Runs Efficiently

After the installation is completed, it is essential to ensure that the new HVAC system and BEMS are running as efficiently as possible. Which steps can businesses take to do so?

“It is important that someone takes responsibility for the BEMS. This includes both the building owners and a maintenance or facility management company who can respond to issues, such as mal-functioning boilers, sticking valves, or to change to the air handlers, air conditioning or boiler systems, as this might require a re-programme of the BEMS to ensure optimum operating is maintained.”

To assist, RDM offers a comprehensive remote monitoring service, ActiveFM. It allows all sites to be monitored remotely, handles alarms, and allows setpoint changes to be made remotely too. This means that all conditions are constantly monitored in real-time and that adjustments and corrections can be made instantly, and at a much lower cost than if a site visit was required.

Taking a comprehensive approach to achieve net zero

To achieve net zero for 80% of the existing buildings in the UK, it is essential to take a comprehensive approach involving both owners and occupiers. In addition to retrofitting efficient HVAC systems and BEMS, it is important to also consider other strategies such as adding sufficient insulation, re-using old building materials during upgrades, installing new energy-saving technologies, and investing in renewable energy.