To provide capacity for ventilation system monitoring to help promote occupant comfort and well-being.
Install permanent monitoring systems to ensure that ventilation systems maintain design minimum requirements. Configure all monitoring equipment to generate an alarm when airflow values or carbon dioxide (CO2) levels vary by 10% or more from the design values via either a building automation system alarm to the building operator or a visual or audible alert to the building occupants.
CASE 1. Mechanically Ventilated Spaces
Monitor CO2 concentrations within all densely occupied spaces i.e., those with a design occupant density of 25 people or more per 1,000 square feet (95 square meters). CO2 monitors must be between 3 and 6 feet (between 1 and 2 meters) above the floor25.
Provide a direct outdoor airflow measurement device capable of measuring the minimum outdoor air intake flow with an accuracy of plus or minus 15% of the design minimum outdoor air rate, as defined by ASHRAE 62.1-2007 (with errata but without addenda26) for mechanical ventilation systems (OR) an
equivalent local standard, where 20% or more of the design supply airflow serves nondensely occupied spaces.
If using a local standard for establishing a baseline and measuring performance relative to that baseline, the following general topics must be addressed for equivalency with ASHRAE Standard 62.1–2007 (with errata but without addenda):
- Ventilation rate procedure
- Indoor air quality (IAQ) procedure
- Design documentation procedures
CASE 2. Naturally Ventilated Spaces
Monitor CO2 concentrations within all naturally ventilated spaces. CO2 monitors must be between 3 and 6 feet (between 1 and 2 meters) above the floor. One CO2 sensor may be used to monitor multiple nondensely occupied spaces if the natural ventilation design uses passive stack(s) or other means to induce airflow through those spaces equally and simultaneously without intervention by building occupants24.
24 If the common hallways are pressurized with respect to the residential units then doors in the residential units leading to the common hallways need not be weather-stripped provided that the positive differential pressure is demonstrated as in Option 2, Case 1 above, considering the residential unit as the smoking room.
25 CO2 monitoring is required in densely occupied spaces, in addition to outdoor air intake flow measurement.
26 Project teams wishing to use ASHRAE approved addenda for the purposes of this credit may do so at their discretion. Addenda must be applied consistently across all LEED credits.