If I comply with the IEQc1 using airflow measurement device that measures outdoor air intake flow with accuracy of plus or minus 15% of design minimum outdoor air rate, as defined by ASHRAE 62.1 -2007, do I lose de IEQc2 increase breathing zone outdoor air ventilation rate by at least 30% above the minimum rates required by ASHRAE Standard 62.1 -2007?
The IEQc1 says that the equipment generate an alarm when the airflow values or CO2 levels vary by 10% and for mechanical ventilated space for non-densely occupied spaces, outdoor airflow measurement device is capable of measure the minimum outdoor air rate with accurancy of plus or minus 15% of design minimum outdoor rate, as defined by ASHRAE 62.1 -2007. What level should I at use to comply with this credit?
Scott DeGaro
Sustainability AdministratorBarge Waggoner Sumner & Cannon, Inc.
80 thumbs up
November 26, 2010 - 12:55 pm
No, you won't lose EQc2 if you also comply with EQc1. EQc1 requires an alarm when the CO2 level varies by 10% from the design values and an alarm when the OA is 15% below the design values. The design values need to be calculated in accordance with ASHRAE 62.1 and the OA sensor needs to have an accuracy of +/- 15%. If you look at the description of the OA Flow Monitoring under paragraph 4 of the reference guide for EQc1 it states the measurement device must detect when the system is 15% below the design minimum OA rate, additional OA is generally a good thing.
So to achieve both credits you'd need to:
1.) Calculate and design the HVAC to provide the minimum ventilation rate per ASHRAE 62.1 (EQp1 and EQc1)
2.) Calculate and design the HVAC to provide the 30% additional ventilation rate compared to EQp1
3.) Install CO2 sensors in densely occupied spaces that detect and alarm when CO2 levels vary by 10% above design levels
4.) Install an OA measurement device that alarms if OA falls 15% below ASHRAE 62.1 minimum ventilation rate