COMMERCIAL HEATING SYSTEMS Decarbonising hard-to-heat depot in London
A major London tram depot has replaced gas heating with infrared technology, demonstrating energy-efficient, targeted warmth for staff while supporting wider carbon-reduction and decarbonisation objectives.
T
ransport for London (TfL) is progressing a major heat decarbonisation and energy efficiency programme as part
of its wider carbon-reduction strategy and the Mayor’s ambition for a net- zero London by 2030. A key element of this effort is the transformation of heating systems across its large operational sites, many of which have historically relied on fossil-fuel technologies. TfL has partnered with Vital Energi at the Therapia Lane tram depot in Croydon. InterLED, the commercial contracts division of Herschel Infrared, was appointed to deliver a fully electric infrared radiant heating and control solution. Fully installed by InterLED in
September-October 2025, the project showcases how infrared technology can replace gas-based convection heating systems in challenging industrial environments, reducing emissions while improving human comfort.
The project The Therapia Lane depot, which operates 24/7, supports various tram maintenance functions across multiple loading bays, workshops and pits, each with distinct heating requirements. Maintaining operational continuity during installation was a key consideration. The project involved the supply and installation of 60 infrared heaters (Herschel Advantage and Herschel Vulcan infrared heaters), covering a total area of 2,400m². The main shed measures 100m by 20m, while the workshop and bogie area measures 35 x 11m. InterLED worked closely with TfL and Vital Energi to assess heating needs, considering workflow patterns, operational requirements, and energy consumption limits. To meet these diverse and complex
conditions, InterLED carried out extensive modelling of optimal heater positioning, zone controllability, and required human comfort levels. There was also a limit on power consumption to factor into the specification, practical limitations of heater positioning and power cable runs, aesthetics and safety to consider. High performance, UK-
manufactured longwave Herschel Advantage heaters were chosen along with low glare, shortwave Herschel Vulcan heaters. This choice
14 Herschel heaters providing warmth for workers at the TfL depot
of different heater types ensured that areas requiring instant, on-demand heating, such as workstations that are infrequently occupied, were effectively heated as required, whilst other heaters were specified to contribute to the overall ambient temperature on a timed/temperature setting. This allowed comfort and efficiency to be optimised based on workflow patterns and controllability demands.
The full specification of infrared
heaters (replacing a gas blower system) included: 12 x Herschel Advantage 1.95kW 13 x Herschel Advantage 2.4kW 18 x Herschel Advantage 4.8kW 17 x Herschel Vulcan 6S 6kW
Smart Controls All heaters are operated via a Herschel control system, which provides zonal heating control, timed scheduling, energy monitoring, and diagnostic capabilities. Zonal control is particularly valuable in large industrial spaces, as it allows heat to be directed where and when it is needed rather than warming the entire air volume. This approach reduces both energy consumption and carbon emissions while maintaining comfortable working conditions. Infrared’s zonal capabilities are
particularly useful in large transport maintenance facilities. By directing heat only where and when it is required, significant reductions in both energy consumption and carbon emissions can be achieved compared to heating the entire volume of air. The heaters radiate heat outwards
The powerful Herschel Vulcan heater is ideal for use in large, high-ceilinged spaces
and downwards, ensuring that operatives remain comfortable within the effective radiant area even when ambient air temperatures fall below minimum workplace thresholds due, for example, to open depot doors. The InterLED project team was
able to use its Thermal Comfort Index modelling to demonstrate that staff working within defined proximity to each heater would maintain comfort regardless of temporary temperature drops from open shed doors.
Infrared is an ideal replacement for gas- powered systems, offering targeted comfort and reduced heat loss
Positive feedback The response from both TfL and Vital Energi has been hugely positive. Comfort levels are being satisfactorily achieved, the Advantage and Vulcan heaters delivering effective, consistent warmth for staff in an energy-efficient and sustainable manner. “We found Herschel and InterLED,
who could supply heaters that aren’t affected by the air,” comments James Merci, TfL Project Manager. “So it was a bit of a no brainer really, for us, and a massive success to get them to where they are now. Already, our staff wellbeing is incredibly high and people are very, very happy with them.” James Asterley, Vital Energi ops manager, adds: “We needed to find a solution that heated people rather than spaces. And the IR heaters that were proposed by our engineers originally were deemed to be the most sensible option…and that’s proved the case. All the feedback has been remarkable really, and the install is really neat/tidy. The team have been
really professional.” ■
www.herschel-infrared.co.uk
EIBI | FEBRUARY 2026
Large industrial and commercial buildings, including transport depots, have always been difficult to heat sustainably and efficiently. High ceilings, open bays, constant vehicle movement and frequent draughts often leave traditional convection- based systems ineffective, as warm air escapes before it can provide meaningful comfort. Infrared heating addresses these challenges by directly warming people, surfaces and objects rather than attempting to heat the surrounding air. Infrared is an ideal replacement for gas-powered systems offering targeted comfort, reduced heat loss and significant carbon-saving potential. The successful deployment of
an infrared heating and controls system at the Therapia Lane tram depot demonstrates the viability of electrified infrared technology for decarbonising hard-to-heat spaces. With measurable improvements in comfort, operational flexibility and carbon reduction potential, the project provides a scalable model for other industrial and transport facilities across the UK. Infrared systems have additional benefits: very low maintenance, no single point of failure, and can be implemented in stages.
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