Best Practices

All occupied spaces in naturally ventilated buildings require the installation of at least one CO₂ sensor. The number of CO₂ sensors depends on the project’s design and should be calculated by the mechanical engineer. Projects can use one CO₂ sensor for multiple spaces only if the project is ventilated by an approved “engineered natural ventilation system” according to ASHRAE 62.1-2007 requirements and if it does not require occupant intervention.

CO2 sensors can 1) measure the indoor concentrations of CO₂ and compare them against ASHRAE 62.1-2007 limits or, 2) measure the indoor concentrations of CO₂ and compare them against outdoor CO₂ concentrations. If you choose the second option, you will need to install outdoor CO₂ monitors as well.

All monitoring devices must be able to trigger an alarm or automated response when actual measurements vary by 10% or more in either direction from the design set points.

For Commercial Interiors projects, verify that any outdoor air monitoring devices or CO₂ sensors are compatible with the existing mechanical equipment and will be able to provide the feedback and corrective action for credit requirements. Providing the appropriate feedback is typically more difficult for CI projects.

Outdoor air can contain contaminants that lead to unhealthy working or living conditions. You may need to assess the quality of the local outdoor air before bringing it indoors. HHigh efficiency MERV filters (13 or higher) are one solution to treating poor-quality outdoor air before supplying it to the indoors.

Demand Control Ventilation (DCV) in conjunction with CO₂ sensors can serve the dual purpose of energy conservation and improved indoor air quality. They provide the option of additional ventilation only when CO₂ sensors indicate that it is necessary.

If relying on natural infiltration in landscaped areas, keep the plants in those areas healthy and avoid soil compaction from vehicle use.

Compacted soil from high vehicle traffic prior to or during construction can severely limit natural infiltration of stormwater. Avoid site compaction during construction as much as possible (This also helps compliance with SSc5.1).

Maintenance is usually needed for stormwater quantity reduction systems. The civil engineer should develop a maintenance plan shortly after design completion.

Soil type, planting medium and plant species must be considered for their capacity to promote infiltration.