Page 288 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

LEED Indoor Envir onmental Quality 251

6.1 IEQ Credit 1: Outdoor Air Delivery Monitoring
The intent of this credit is to verify the presence of adequate air exchanges with the
outside. It is assumed that if there is sufficient air exchange with the outside, then
potential contaminants will not build up in the indoor airspace. This credit changed
significantly from the requirements in LEED-NC 2.1, with the LEED-NC 2.2 revision,
but has not been revised significantly by the LEED 2009 version. LEED 2009 does
provide guidance for buildings with limited airflow monitoring capabilities. IEQc1 is
worth one point in both LEED 2.2 and LEED 2009.

USGBC Rating System
LEED-NC-2.2 lists the Intent, Requirements, and Potential Technologies and Strategies
for IEAQc1 as follows, with additional LEED 2009 revisions included:

Intent
Provide capacity for ventilation system monitoring to help sustain occupant comfort and
well-being.
Requirements
Install permanent monitoring systems that provide feedback on ventilation system
performance to ensure that ventilation systems maintain design minimum ventilation
requirements. Configure all monitoring equipment to generate an alarm when the conditions
vary by 10% or more from setpoint (for the carbon dioxide monitors), via either a building
automation system alarm to the building operator or via a visual or audible alert to the
building occupants.
AND
FOR MECHANICALLY VENTILATED SPACES (Case 1 in LEED 2009)
• Monitor carbon dioxide concentrations within all densely occupied spaces (those
with a design occupant density greater than or equal to 25 people per 1000 sq. ft.). CO
2
monitoring locations shall be between 3 feet and 6 feet above the floor.
• For each mechanical ventilation system for which 20% or more of the design airflow
is serving non-densely occupied spaces, provide a direct outdoor airflow measurement
device capable of measuring the minimum outdoor airflow rate 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 addenda). (Also, in LEED 2009, the ASHRAE 62.1-
2007 addenda may be used by project teams but only if consistently used throughout
all the LEED credits.)
FOR NATURALLY VENTILATED SPACES (Case 2 in LEED 2009)
Monitor CO concentrations within all naturally ventilated spaces. CO monitoring shall be
2 2
located within the room between 3 feet and 6 feet above the floor. One CO sensor may be
2
used to represent multiple 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 occupants.
Potential Technologies and Strategies
Install carbon dioxide and airflow measurement equipment and feed the information to the
HVAC system and/or Building Automation System (BAS) to trigger corrective action, if
applicable. If such automatic controls are not feasible with the building systems, use the
measurement equipment to trigger alarms that inform building operators or occupants of a
possible deficiency in outdoor air delivery.