NYC-WTC_000229470

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan April 17, 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 12:40 P.M.

Temperature

Indoor dry bulb temperature measurements ranged from 73.0°F to 77.4°F. Sixty-six (66) of the measurements were above the range of 68 to 75°F (at 50 percent relative humidity) recommended by ASHRAF Standard 55-1992 during the heating season (wintertime conditions). The outdoor temperature range was 73.4 to 76.2°F.

Relative Humidity

The relative humidity indoors ranged from 51.6 percent to 58.3 percent. All measurements were within the ASHRAE-recommended range of 30 to 60 percent for occupant comfort.. The outdoor relative humidity levels were 57.2 and 62.1 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 429 ppm to 1245 ppm. One (1) of the CO2 measurements was above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO2 concentrations were 448 and 526 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1226 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 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 2 ppm.

Respirable Particulates (PM2_j)

Respirable particulate concentrations* indoors ranged between 15 pg/m3 to 39 pg/m^ with an average of approximately 17 ug/nC. 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 or the USEPA recommendation of 40 pg/m^ for sensitive individuals and children. The outdoor respirable particulate concentrations were 66 and 68 pg/m^.

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