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Minimum Indoor Air Quality Performance

Ventilation

This prerequisite requires compliance with ASHRAE 62.1-2010 for mechanical, natural, and mixed-mode ventilation systems.

Most building codes and mechanical codes require ventilation, either referencing ASHRAE 62.1 or using with similar requirements, so this prerequisite will not add any significant cost premium to most projects.

Basic calculations should already be part of the project HVAC load calculations. If your jurisdiction does not require you to submit ventilation calculations, plan on some extra time to calculate the ventilation quantities and compile your LEED documentation.

Monitoring

New in LEED v4, this prerequisite incorporates previously optional ventilation monitoring.

When using a mechanical ventilation system, adding air flow measurement to rooftop units, air handlers, or even to a dedicated outdoor air system (DOAS) unit is usually a simple matter of specifying the unit manufacturer’s outdoor air measurement option or selecting a dedicated air flow measurement device from a manufacturer for field installation. Control systems should be robust enough to track and log airflow readings and generate an alarm if readings vary from the setpoint by more than 15%.

In naturally ventilated spaces, projects must install COsensors in each thermal zone, or install sensors to confirm that natural ventilation openings such as operable windows are actually open during occupied hours. Airflow sensors in exhaust systems operating during occupied hours may also be used. 

Cost Synergies

EAp2/EAc2: Energy Performance
EQc1: Enhanced Indoor Air Quality Strategies
EQc5: Thermal Comfort 

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