Operating four huge passenger terminals, covering almost 600,000 square metres, the amount of energy used in creating a comfortable indoor climate for passengers, shopkeepers and employees is massive.

Energy project manager, Andy Dobbs, is responsible for energy saving projects related to all HVAC installations in the terminals.

Since 2016, Mr Dobbs has been working with Munters’ climate control specialists on an extensive energy saving upgrade of air handling equipment in the terminals.

By replacing older, often belt driven, AHU exhaust and process fans with smaller, more energy efficient and maintenance free EC fans in a fan wall configuration, Heathrow has been able to reduce energy consumption on these AHUs by 30-60 percent.

In total, Munters has upgraded more than 150 AHUs, resulting in the installation of approximately 500 EC fans.

Energy savings on these projects amount to an impressive total of 15 GWh, which is equal to the annual energy consumption of no less than 3,400 households, based on UK average.

Overnight upgrade work

Mr Dobbs said: “Thanks to Munters’ experience and modular frame and fan plate system, a fan upgrade, typically consisting of a fan wall with three to six EC fans, can be performed in one single night shift. For Heathrow, that means that the upgrade work itself will have no negative impact on the daily operation, just as passengers and partners in the airport will not be affected.

“Energy saving from a small fan upgrade like this, taking place over only one night, is equal to the savings from replacing 1,000 light bulbs with LED lights, which would take a month to do.”

AHUs of very different sizes and age have been upgraded, the smallest with an airflow of 5,000 m3/h, the biggest being a plant consisting of four huge AHUs in Terminal 5 (T5), each supplying 230,000 m3/h.

Mr Dobbs added: “The extensive documentation provided by Munters in the project phase is important when planning and budgeting for further energy saving projects. Being able to verify savings between 30-60 percent, the short ROI at only two and a half to three years, make the AHU upgrades very interesting for Heathrow and helps us in reaching our energy saving goals.”

On top of the energy saved, there are a number of other benefits which have an important impact on both daily operation and passenger comfort. These include improved reliability, reduced maintenance, a reduced need to keep spare parts in stock, and reduced noise and vibration level.

After the successful completion of the project, continuous data logging has verified the calculations, and in total the T5 project saves Heathrow no less than 1.5 GWh per year. 

EC plug fans

Energy efficiency has become an integral part of building services design, maintenance and upgrade. Many organisations overlook AHUs when looking to save energy.

Upgrading AHUs with plug fans using EC motor technology can realise significant savings in energy, maintenance and more. Munters has developed a fan wall configuration concept that is pre- designed and makes installation on site easy and very time efficient.