Columbia Property Trust implemented a demand control ventilation system at one of its office buildings in Atlanta to improve HVAC efficiency and reduce costs. McKenney's Automation & Control Solutions team recommended installing CO2 monitors and a DCV system to automatically adjust outside air ventilation based on occupancy levels. This lowered the HVAC load by an estimated 70 tons and energy usage by 65,000 kWh per month while maintaining comfort. The project achieved a return on investment of less than four months.

1. PROJECT HIGHLIGHTS
Demand Control
Ventilation Reduces HVAC
Load, Saves Costs
C
olumbia Property Trust has
had a longtime commitment
to ­ ustainable practices that
s
maximize energy efficiency and reduce
e
­ nvironmental impact on the community.
Its 14-story, 353,000-square-foot suburban
S
­ olutions (ACS) team for insight and
r
­ ecommendations to improve its HVAC
­system efficiency.
After thoroughly reviewing the facility,
M
­ cKenney’s recommended an innovative
approach to monitor and adjust the
building’s outside air ventilation levels
based on ASHRAE 90.1 standards. The
solution involved introducing Demand
Control Ventilation (DCV) to monitor
the amount of outside air entering the
building based on carbon dioxide (CO2)
concentrations. CO2 levels continuously fluctuate in a building as its
­population changes.
DCV continuously monitors each
floor in a building and automatically
adjusts outside air ventilation rates.
This is achieved by using controls
Photo courtesy of Columbia Property Trust
and variable frequency drive (VFD)
office building in Atlanta had already
technology as needed, while still meeting
®
achieved ENERGY STAR certification and
ASHRAE ventilation standards. By optimizing
consistently maintained a score of 87,
the amount of outside air coming into the
p
­ utting the ­ tructure in the top tier of the
s
building, there is less air that has to be
15 percent most energy-efficient buildings
heated or cooled, resulting in a reduced
in the U.S.
load on the HVAC system.
However, Columbia Property Trust still had
room for improvement. With aspirations of
achieving even greater energy efficiency,
the senior property manager approached
the McKenney’s Automation & Control
To ensure the solution was as effective as
possible for the company, the McKenney’s
ACS team installed CO2 monitors in the
building, added custom programming
for certain aspects of the project and
The content of this document is not intended as an endorsement.
For more information contact McKenney’s at 404-622-5000.
info@mckenneys.com  www.mckenneys.com
McKenney’s, Inc.  1056 Moreland Industrial Boulevard, Atlanta, Georgia 30316
Project Team
žž Owner: Columbia Property Trust
žž General Contractor:
McKenney’s, Inc.
The Challenge
žž Provide energy-saving
solutions with quick ROI
žž Maintain tenant comfort
žž Comply with ASHRAE standards
The Solution
žž Introduced DCV system to monitor
outside air entering building
žž Installed CO2 monitors
žž Custom programming and
r
­ eprogramming of controls
The Results
žž Average of 65,000 kWh per
month energy usage reduction
žž Solutions meet ASHRAE standards
žž ROI was less than four months
žž Comfortable and healthy
e
­ nvironment for tenants
r
­ eprogrammed the existing controls system
to effectively integrate the DCV solution.
Since installing the DCV system, the load on
the building’s HVAC system has been substantially reduced by an estimated 70 tons
on a 70-degree day. In turn, this solution
lowered the energy usage for the building
by an average of 65,000 kWh per month
since installation while maintaining a comfortable environment for tenants. The DCV
solution also achieved a quick return on
investment (ROI) of less than four months.
Copyright © 2013 McKenney’s, Inc., Atlanta, Georgia. All rights reserved. Printed in the U.S.A.
McKenney’s, Inc. and the McKenney’s, Inc. logo are registered trademarks of McKenney’s, Inc. All other trademarks are the property of their respective owners.