An office building in London has cut the energy used by its ventilation system by 31% after deploying IoT sensors and intelligent controls on top of its existing building management system (BMS).
The project at 3 Pancras Square, a 10-storey commercial building at King’s Cross Estate occupied by Havas UK, was designed to find further efficiency gains from a ventilation system that was already using 70% heat recovery and CO₂-based optimisation.
Rather than replacing the heating, ventilation and air conditioning (HVAC) infrastructure, building technology company Envelo used its software to optimise the existing system in real time.
Independent analysis by engineering consultancy Hoare Lea found a 31% reduction in ventilation energy use across the independently validated part of the building. The project had a reported 13-month payback.
The results suggest that buildings with relatively efficient HVAC systems may still have scope to reduce energy consumption by using more granular data on occupancy and indoor conditions.
Envelo’s software sits above the existing BMS and uses data from IoT sensors measuring CO₂, temperature, humidity, volatile organic compounds (VOCs) and particulate matter, alongside outdoor conditions.
The platform uses this information to calculate how much ventilation is required and sends control instructions to the existing BMS.
At 3 Pancras Square, the system was used to optimise the building’s constant air volume (CAV) ventilation system. Airflow was reduced when demand was lower, while ventilation was switched off during periods of low occupancy or when indoor conditions allowed.
Ventilation was switched off for an average of 21 hours a week per floor, equivalent to 42% of operating hours, according to Envelo.
The reduction in ventilation did not result in a deterioration in the indoor environment. Measurements showed that the amount of time spent above 1,200 parts per million (ppm) CO₂ fell by 23%, while periods of overly dry air fell by 34%.
Breaches of PM2.5 thresholds fell by between 70% and 100%, while exposure above the specified VOC threshold declined by about 20%.
Havas said that no complaints about stuffiness or discomfort were reported during the project.
“At Havas, we are committed to reducing energy consumption and CO₂ emissions whilst continuing to provide healthy, high-performing workplaces for our people,” said Joe Nettleton, Building Services Director at Havas UK. “Envelo’s SaaS solution has been instrumental in delivering energy savings and IEQ improvements in the face of a technically challenging environment.”
Envelo estimates that applying the results across the whole building could deliver annual energy cost savings of £46,000, alongside 31 tonnes of CO₂e savings a year.
The company said the latter would represent a 5.8% reduction in Havas UK&I’s total Scope 2 emissions.
Steve Burch, co-founder and chief operating officer at Envelo, said: “The results show that there can still be significant opportunities to improve building performance by using real-time data and intelligence to optimise existing infrastructure. At 3 Pancras Square, that has meant substantially reducing ventilation energy use while maintaining or improving indoor air quality, without the capital cost and disruption of replacing the HVAC system.”
