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.