Indoor Air Quality Report, April 9, 2002, NYC School

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan April 10, 2002 Indoor Air Quality Assessment Page 3 H.S. of Economics and Finance (M833) ATC Project No. 15-19125-0291 Real-Time Environmental Measurements

ATC collected one hundred (100) sets of real-time environmental measurements consisting of eighty-eight (88) in the school building and twelve (12) outdoors. Field data sheets are found in the Attachment. Readings began at 9:25 A.M. and concluded after 3:00 P.M. The results are described below.

Temperature

Indoor dry bulb temperature measurements ranged from 68.7 °F to 78.4 °F. Thirty-four (34) of the indoor measurements for temperature were above 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 65.7 to 73.2 °F.

Relative Humidity

The relative humidity indoors ranged from 30.2 percent to 52.1 percent. All of the indoor measurements for relative humidity were within the ASHRAE recommended range of 30 to 60 percent for occupant comfort. The outdoor relative humidity ranged from 41.9 to 49.1 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 419 ppm to 1007 ppm. All of the indoor measurements for CO2 were below the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO;? concentration was 452 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1152 ppm (background level + 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 Monoxid^oncerdrgtion

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

Respirable Particulates (PM2 §)

Respirable particulate concentrations* indoors ranged between 1 (ug/m^ to 24 pg/m^ with an average 8 pg/m^- None of the indoor measurements were above the NPAAQS of 65 pg/m^ 24- hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter and the USEPA recommended concentration of 40 pg/m3 for sensitive individuals and children. The outdoor respirable particulate concentration ranged from 29 pg/m^ to 51 pg/m^ with an average of 45 pg/m^. None of the outdoor measurements was above the NPAAQS of 65 pg/m3 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter. Eight (8) of the twelve (12) instantaneous outdoor reading were above the L SEPA recommended concentration of 40 pg/m^ for sensitive individuals and children. * The measurements made during this assessment were instantaneous readings, the NPAAQS is a 24-hour average.

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