Harley-Davidson America’s
favorite motorcycle manufacturer, Harley-Davidson Motor
Company, attributes its success in part to maintaining
a comfortable and healthy work environment for its employees.
Part of this healthy
work environment includes unconditionally guaranteed indoor
air quality through the use of CO2
monitoring and control at its corporate headquarters in
Milwaukee, Wisconsin.
“The quality of the air in our workspace will consistently
exceed OSHA and EPA fresh air standards,” was
the promise made by Harley-Davidson’s facilities department,
to employee’s four years ago. Maintaining a proper ventilation
rate is a critical part of indoor air quality. Monitoring
and controlling ventilation based on CO2
allows an HVAC
system to maintain the proper ventilation rate at all
times. When CO2 levels are high
ventilation levels are low and people can experience
drowsiness, headaches and stuffiness that may impair their
comfort and productivity. For Harley-Davidson, good ventilation
is the key to its indoor air quality guarantee.
To achieve its guarantee Harley-Davidson chose
to utilize a CO2 demand controlled
ventilation (DCV) system with sensors from Telaire. “Telaire's
sensors are reliable, technologically advanced and require
very little maintenance” according to Dennis Kerlin, stationary
engineer at Harley-Davidson.
Harley-Davidson
uses an energy management system manufactured by Automated
Logic Corporation. The system’s computer program allows
Harley-Davidson to use CO2 sensors
to automatically control the amount of outside air coming
into the building. There are two CO2
sensors and air handlers per floor for each of the building’s
six floors, and each operates independently of the others.
As occupancy increases in a section of the building, and
the CO2 level starts to increase,
the CO2 sensor in that area automatically
signals the energy management system to deliver more fresh
air to the space. This allows the ventilation system to
automatically keep up with changes in occupancy inside
the building.
CO2
demand controlled ventilation is part of a comprehensive
indoor air quality strategy at
Harley-Davidson. Temperature, humidity and carbon dioxide
levels are monitored 24 hours a day, and results are logged
and charted twice daily. Air is humidified in winter and
dehumidified in summer to levels between 30 and 60 percent.
Airborne particles are filtered, and fresh outdoor air
is introduced year round.
Employees
are assured of indoor air quality and can monitor CO2
levels in real time by checking large digital readouts
that are prominently displayed throughout the building.
Occupants are ensured that CO2 concentration
levels remain at or below 1000 parts per million (PPM)
which indicates that ventilation rates of 20 cfm per person
are maintained at all times, as recommended by the American
Society of Heating, Refrigerating and Air Conditioning
Engineers (ASHRAE).
This
system was put to the test during a recent renovation
of the 230,000 square foot corporate headquarters
building. The building remained occupied during the renovation
so maintaining adequate ventilation was particularly important
for employee health and productivity. “Telaire's sensors
helped us to maintain productivity despite the dust and
debris from construction,” said Kerlin.
In
addition to maintaining recommended ventilation rates
and the associated air quality benefits, Telaire's sensors
can help reduce energy costs. CO2
sensors allow HVAC systems to change ventilation rates
based on the actual number of people in a building. If
a building is only 50% occupied the CO2
level will reflect this and the sensors will automatically
signal the HVAC system to bring in only enough outside
air to accommodate the actual number of people in the
building. Most HVAC systems without CO2
sensors have to assume full occupancy regardless of the
actual number of people in the building, which results
in very costly over-ventilation. In fact, CO2
DCV systems have been shown to lower energy costs between
$0.10 and $0.55 per square foot while maintaining ASHRAE
recommended ventilation rates.