Indoor Air Quality Report, March 1, 2002, NYC School

NYC 9/11 Public Portal Document

J Mr. Bernard P. Orlan March 4, 2002 Indoor Air Quality Assessment Page 3 H.S. of Economics and Finance fM8331 ATC Project No. 15-19125-0291

Real-Time Env»onmental Measurements

ATC collected one hundred thirty-eight (138) sets of real-time environmental measurements consisting of one hundred twenty-six (126) in the school building and twelve (12) outdoors. Field data sheets are found in the Attachment. Readings began at 9:06 A.M. and concluded after 3.10 P.M. The results are described below.

Temperature

Indoor dry bulb temperature measurements ranged from 57.9 °F to 71.3 °F. Eighty-one (81) of the indoor measurements were below the range of 68 to 75°F (at 50 percent relative humidity) recommended by ASHRAE Standard 55-1992 during the heating season (wintertime conditions). The outdoor temperature ranged from 44.6 to 50.8 °F.

Relative Humidity

The relative humidity indoors ranged from 19.8 percent to 33.9 percent. One hundred twenty- three (123) measurements were below the ASHRAE-recommended range of 30 to 60 percent for occupant comfort. All other measurements were below the ASHRAE recommended range. The outdoor relative humidity ranged from 20 to 23.4 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 537 ppm to 1091 ppm. All of the indoor measurements were below the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO2 concentration was 421 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1121 ppm (background level -t- 700 ppm). Levels above the recommended maximum do not indicate a health risk. Carbon dioxide measurements are used as an indicator of available outdoor air. The primary source of CO2 indoors is occupant respiration.

Carbon Monoxide Concentration

Carbon monoxide concentrations indoors were 0 to 3 ppm. These concentrations were below the NPAAQS/ASHRAE guideline of 9 ppm. The outdoor CO concentration ranged from 2 to 4 ppm.

Respirable Particulates (PM2_5)

Respirable particulate concentrations* indoors ranged between 0 pg/m^ to 42 pg/m3 with an average 7 pg/m^- None of the measurements were above the NPAAQS of 65 pg/m3 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter. The PM2.5 average concentration was also below the USEPA recommended concentration of 40 pg/m^ for sensitive individuals / children. The outdoor respirable particulate concentration ranged from 29 pg/m^ to 70 pg/m^ with an average of 41 ug/m^.

* The measurements made during this assessment were instantaneous readings, the NPAAQS is a 24-hour average.

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