New and Underutilized Technology: Carbon Dioxide Demand Ventilation Control
The following information outlines key deployment considerations for carbon dioxide (CO2) demand ventilation control within the Federal sector. This information spans:
Benefits
Demand ventilation control systems modulate ventilation levels based on current building occupancy, saving energy while still maintaining proper indoor air quality (IAQ). CO2 sensors are commonly used, but a multiple-parameter approach using total volatile organic compounds (TVOC), particulate matter (PM), formaldehyde, and relative humidity (RH) levels can also be used.
CO2 sensors control the outside air damper to reduce the amount of outside air that needs to be conditioned and supplied to the building when occupancy is low. This works especially well for conference rooms and auditoriums with frequent low occupancy, but must be designed to supply outside air volume for worst-case scenarios.
Application
CO2 demand ventilation control systems are most applicable in rooms with variable occupancy, such as conference rooms.
Key Factors for Deployment
CO2 demand ventilation control systems work especially well in conference rooms and auditoriums that are frequently at low occupancy, but must be designed to supply outside air at volume for worst-case scenarios.
These systems are offered by all major HVAC equipment and control companies.
Ranking Criteria
Federal energy savings, cost-effectiveness, and probability of success are ranked 0-5 with 0 representing the lowest ranking and 5 representing the highest ranking. The weighted score is ranked 0-100 with 0 representing the lowest ranking and 100 representing the highest ranking.
| Federal Energy Savings | Cost Effectiveness | Probability of Success | Weighted Score |
|---|---|---|---|
| 0.5 | 5.0 | 3.8 | 50 |
Resources
The following resources are available:
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Demand-Controlled Ventilation Using CO2 Sensors: FEMP overview of preventing energy losses from over-ventilation while maintaining indoor air quality.
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HVAC Systems: U.S. Environmental Protection Agency (EPA) overview of HVAC system technologies and applications.
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School Advanced Ventilation Engineering Software (SAVES): EPA software package to help school designers access the potential financial payback and indoor humidity benefits of energy recovery ventilation systems.
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Review of Demand Control Ventilation: Lawrence Berkeley National Laboratory (LBNL) report covering the technology behind and application of demand control ventilation.
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Assessment of Energy Savings Potential from the Use of Demand Control Ventilation Systems in General Office Spaces in California: LBNL report reviewing demand control ventilation applied to medium-sized office space meeting the prescriptive requirements of the 2008 California building energy efficiency standards.
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Demand Control Ventilation using CO2: ASHRAE Journal article covering CO2-based demand control ventilation to modulate outside air ventilation based on real-time occupancy.
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Smart Demand Control Ventilation: Article covering intelligent ventilation measurement, optimization, and new thinking for today's green buildings.
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Demand Control Ventilation - The Right Amount Ventilation at the Right Time and Place for 20% Less: Carrier article and resources provided as part of the United Technologies Corporation.