Indoor air quality report, PS 89M, Feb 2002

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan February 6, 2002 Indoor Air Quality Assessment Page 3 P. S. 89M ATC Project No. 15-19123-0997

Real-Time Environmental Measurements

ATC collected eighty (80) sets of real-time environmental measurements consisting of eight (8) outdoors and thirty-two (32) inside in the morning (A.M.) and the same number of readings in the afternoon (P.M.). AH five floors of the school were surveyed. The field data sheets are found in the Attachment. Readings began at 8:00 A.M. and concluded after 3:30 P.M. The results are described below:

Temperature

Indoor dry bulb temperature measurements ranged from 64.5°F to 70.4°F (A.M.) and 64.6°F to 75.0°F (PM). Eleven (11) measurements in the morring and four (4) measurements in the afternoon 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 average outdoor temperature wa> 38.9°F (A.M.) and 34.3°F (P.M.).

Relative Humidity

The relative humidity indoors ranged from 10.4 to 22.8 percent (A.M.) and 10.2 to 19.1 percent (P.M.). All readings were below the ASHRAE-recommended range of 30 to 60 percent for occupant comfort. The outdoor relative humidity averaged 17.7 percent (A.M.) and 16.1 percent (P.M.).

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 460 to 1326 ppm (A.M.) and 480 to 1102 ppm (P.M.). Two (2) CO2 measurements collected in the morning were above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO2 concentrations averaged 456 ppm (A.M.) and 459 ppm (P.M.). Therefore, the maximum acceptable level of CO2 at this location was 1159 ppm (background level ■+• 700 ppm). The highest indoor level was measured in Classroom 404. Levels above the recommended maximum do not indicate a health risk. Carbon dioxide measurements are used as an indicator of available ouldoor air. The primary source of CO2 indoors is occupant respiration. The 2'”''^ and 3''^ floors of the school building were not occupied during ATC’s assessment.

Carbon Monoxide Concentration

Carbon monoxide concentrations indoors were 0 ppm for all readings. These concentrations were below the ASHRAE guideline of 9 ppm. The outdoor CO concentration was also 0-1 ppm.

Respirable Particulates (PM2,5)

Respirable particulate concentrations* indoors ranged from 6 pg/m^ to 19 pg/m^ (A.M.) and 6 pg/m^ to 13 pg/m^ (P.M.). AH indoor measurements were below the NPAAQS of 65 pg/m^ 24- hoLir average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter. The average PM2.5 concentration* for the entire school building was approximately 12 pg/m3 (A.M.) and 9 pg/m^ (P.M.). All A.M. and P. M. indoor measurements were also

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