How Salesforce cut HVAC energy 38% as a tenant, with no building works
By Frederik Hendriksen, Co-founder and CEO
This week in Chicago, our project with Salesforce won CoreNet Global’s highest honor, the 2026 H. Bruce Russell Global Innovator’s Award.
The award matters. The project matters more, because it answers the question we hear from almost every corporate real estate leader: how do you cut the energy and carbon of a building you don’t control?
Tenants pay for HVAC they can’t change
In most offices, the tenant pays the energy bill and the landlord owns the plant. Replacing it means capex, disruption and a long negotiation. The tenant still owns the net-zero target, and HVAC is one of the biggest energy loads in the building.
Salesforce is a tenant at Salesforce Tower, a 46-floor, BREEAM Excellent building in central London. Its Real Estate & Workplace Services team didn’t wait for a capital project. They asked whether the systems already in the building could do more.
Five hours to install
We installed in January 2024, in five hours on a Saturday. After two weeks of baseline data, we made the changes in two phases in March:
- Rensair’s analysis right-sized the airflow through the existing air handling units, so the building brings in, heats, cools and moves less outdoor air.
- Connected Rensair Core units clean the air already in the space, monitoring indoor air quality and responding to changes.
Nothing was ripped out. Nothing needed the landlord’s capital.
38% less HVAC energy
HVAC energy fell from 920,043 kWh to 573,228 kWh: 346,815 kWh saved, a 38% cut. That avoided 71 metric tons of CO2e, about the CO2 from 17 UK homes’ energy use for a year.
Cleaner air, too
Mean PM2.5 fell 30% and peak PM2.5 fell 56%. CO2 rose from 711 to 841 ppm as less outdoor air came in, and stayed well within healthy ranges. Lower energy and cleaner air, with no trade-off on comfort.
Where this fits
Tenant-led retrofits work best where:
- the tenant’s space is served by central HVAC it doesn’t own
- there’s a net-zero or energy target with a deadline
- a capital project is off the table, or years away
Most of the buildings we’ll occupy in 2050 already exist. Making them work smarter is the fastest way to decarbonize them, and as Salesforce showed, tenants don’t have to wait.
Thank you
To Relina Bulchandani and the Salesforce team, for backing a new idea before it had an award attached to it. To CoreNet Global, the judges and Gensler, the award’s founding sponsor. And to our team in London and New York, who made the numbers real.
Want to know what this could look like in your offices? We’ll run the numbers for you.