British Land's flagship headquarters, York House, is benefitting from new heat pump technology that has fully replaced the use of gas.
York House is a five-story, multi-tenanted office building in Marylebone, which previously relied on gas boilers for heating and requires 24-hour cooling with extended fresh air requirements.
Air-source heat pump chillers
To decarbonize the building, British Land opted for two Mitsubishi Electric air-source heat pump chillers and one water-to-water heat pump to replace four gas boilers and an old chiller system.
This was part of a wider goal to reduce operational carbon by 75% and energy use by 25% by 2030. The result is a building with heat pumps that deliver a more than 400-kilowatt-hour reduction in energy use year over year.
heat pump technology
The design of the solution was provided by 21 Engineering, and the starting point was identifying the peak load
Matt Beales, Head of Technical Project Delivery at British Land, said, "The project at York House is unique because it was the first building where we achieved a full gas removal using heat pump technology. Our previous projects have been hybrid with gas being retained, but with this one, we wanted to lead by example as it's our head office."
The design of the solution was provided by 21 Engineering, and the starting point was identifying the peak load to increase efficiency.
demand-driven strategy
"We came up with the principle that we could utilize a 95% peak load to minimize the equipment size and optimize the project costs," explained Phil Draper, Managing Director of 21 Engineering.
"We looked at controlling the building on a demand-driven strategy, which means that the building isn't allowed to get cold, and that reduces the time needed to heat it and maximizes the efficiency of the heat pump technology."
Addressing the challenges
Following the project design, two other main challenges had to be addressed: (1) limited roof space and (2) installing the new heating system in a fully operational building.
A structural survey of the rooftop was carried out, and the installer, Nationwide Air Conditioning, 3-D modeled the pipework and surrounding areas to ensure the units fit.
high EPC ratings
Mitsubishi Electric heat pump chillers also help British Land reuse waste heat from the process to heat
Geoff Broughey, Senior Technical Services Manager for British Land and York House, explained, "We decided to complete the works within normal office hours, so nearby apartments weren't disturbed, which meant the office building was fully occupied. Most of the work occurred on the roof, so the building occupants weren't aware."
The Mitsubishi Electric heat pump chillers also help British Land reuse waste heat from the process to heat the building and minimize energy consumption. The four-pipe heat pumps use R513A, a refrigerant with a lower global warming potential (GWP). R513A has also helped British Land achieve the highest possible Energy Performance Certificate (EPC) rating.
high efficiency, low costs
Daniel Valente, Head of Projects for Nationwide Air Conditioning summarised the challenge, “The unique aspect of this project was that we had no hydronic separation and a much lower capacity on the water-to-water side so that we only injected the amount of heat required to give the building the load required during the winter months."
“The benefits to this were higher operational efficiencies, lower initial capital costs, and a simpler installation.”