Indoor air quality report, PS 89M, Feb 7 2002

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan February 8, 2002 Indoor Air Quality Assessment Page 3 P. S. 89M ATC Project No. 15-19125-0297

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.). .All five floors of the school were surveyed. The field data sheets are found in the Attachment. Readings began at 8:05 A.M. and concluded after 4:00 P.M. The results are described below:

Temperature

Indoor dry bulb.temperature measurements ranged from 63.5°F to 75.3°F (A.M.) and 66.9°F to 73.0°F (PM). In the morning, two (2) measurements Avere above and six (6) 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) white in the afternoon seven (7) measurements were below the same recommended range. The average outdoor temperature was 39.7°F (A.M.) and 52.9°F (P.M.).

Relative Humidity^

The relative humidity indoors ranged from 15.4 to 25.4 percent (A.M.) and 26.5 to 37.1 percent (P.M.). Fifteen (15) measurements collected in the afternoon were within the ASHRAE- recommended range of 30 to 60 percent for occupant comfort. All other readings were below the recommended range. The outdoor relative humidity averaged 42.3 percent (A.M.) and 36.0 percent (P.M.).

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 520 to 1019 ppm (A.M.) and 535 to 999 ppm (P.M.). All CO2 measurements collected were below the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) COp concentrations averaged 494 ppm (A.M.) and 537 ppm (P.M.). Therefore, the maximum acceptable level of COp at this location was 1237 ppm (background level + 700 ppm). The highest indoor level was measured in Classroom 504. 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 COp indoors is occupant respiration. The 2'1^) and 3*’d floors of the school building were not occupied during ATC’s assessment.

Carbon Monoxide Concentration

Carbon monoxide concentrations indoors ranged from 0 to 1 ppm. These concentrations were below the ASHRAE guideline of 9 ppm. The outdoor CO concentration was 0 ppm.

Respirable Particulates (PM2^§}

Respirable particulate concentrations* indoors ranged from 21 pg/m^ to 42 pg/m^ (A.M.) and 30 pg/m^ to 78 pg/m3 (P.M.). Six indoor measurements collected in the afternoon were above the NPAAQS of 65 pg/m^ 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter. The average PM2.5 concentration* for the entire school

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