Empire State Building Uses CO2 for HVAC Control
The owners of the landmark building decided on a long-term plan to reduce energy and water usage costs in order to make rents more competitive with newer properties and to reduce the building’s CO2 “footprint.”
Out of 66 plans for reducing the building’s energy requirements proposed, eight were chosen for their ability to create the highest return on investment for the building owners. One of the eight projects was to upgrade the fresh air dampers using CO2 control.
All commercial buildings are required to provide a minimum amount of fresh air to occupants to ensure adequate air quality. CO2 sensors are used to measure CO2 concentrations in occupied spaces. This information is then passed on to new variable-rate fresh air dampers that provide the appropriate amount of outside air to bring into each office.
The CO2 sensor retrofit portion of the project alone is estimated to save 300 tons/yr CO2, 4.6M kBtu/yr, and $117K/yr in energy costs. This equates to .70 to .90 cents per square foot annual energy cost savings for the owners and tenants.