NYC-WTC_000229474

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan April 24, 2002 Indoor Air Quality Measurements Page 3 Stuyvesant High School (M477)_______________ ATC Project No. 15-19125-0246 Real-Time Environmental Measurements

ATC collected one hundred and twenty (120) sets of real-time environmental measurements consisting of one hundred and eighteen (118) in the school building and two (2) outdoors. All ten floors of the school were surveyed. These results are described below.

Field data sheets are found in Attachment 1. Readings began at 8;00 A.M. and concluded after l.TOP.M.

Temperature

Indoor dry bulb temperature measurements ranged from 66.3 °F to 74.5 °F. Seventy-two (72) of the measurements for indoor temperature were below and forfy-six (46) measurements were within the range of 73 to 79°F (at 50 percent relative humidity) recommended by ASHRAE Standard 55-1992 during summer conditions. The outdoor temperature range was 48.4 to 49.2°F.

Relative Humidity

The relative humidity indoors ranged from 27.6 percent to 36.6 percent. Twenty-five (25) of the indoor measurements for relative humidity were below and ninety-three (93) measurements were within the ASHRAE-recommended range of 30 to 60 percent for occupant comfort. The outdoor relative humidity levels were 28.1 and 31.2 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 105 ppm to 1189 ppm. Eleven (11) measurements were above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO2 concentrations were 362 and 420 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1120 ppm (background level ■+• 700 ppm). The highest concentration (1189 ppm) was measured in room 1006 at 12:50 PM with 30 occupants. 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 ranged from 0 ppm to 1 ppm. These concentrations were below the NPAAQS/ASHRAE guideline of 9 ppm. The outdoor CO concentrations were 1 ppm for all readings.

Respirable Particulates (PM2,5)

Respirable particulate concentrations* indoors ranged between 6 pg/m3 to 15 pg/m^ with an average of approximately 10 pg/m^. All of the indoor measurements for PM2.5 were below the NPAAQS of 65 pg/m- 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter and the USEPA recommendation of 40 pg/m3 for sensitive individuals and children. The outdoor respirable particulate concentrations were 10 and 16 pg/m^.

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NYC-WTC_000229476