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NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan February 18, 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-one (121) sets of real-time environmental measurements consisting of one hundred and nineteen (119) in the school building and two (2) outdoors. All ten-floors of the school were surveyed. These results are described below. t' Field data sheets are found in Attachment 1. Readings began at 8:05 A.M. and concluded after 1:30 P.M.

Temperature

Indoor dry bulb temperature measurements ranged from 68.3°F to 73.8°F. All of the measurements were within the range of 68 to 75°F (at 50 percent relative humidity) recommended by ASHRAE Standard 55-1992 during the heating season (wintertime renditions). The outdoor temperature range was 46.1 to 47.8 °F.

Relative Humidity

The relative humidity indoors ranged from 24.2 percent to 29.6 percent. All of the measurements were below the ASHRAE-recommended range of 30 to 60 percent for occupant comfort. The outdoor relative humidity levels were 35.6 and 36.2 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 516 ppm to 1.126 ppm. All of the CO2 measurements were below the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO2 concentrations were 538 and 567 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1267 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 were 0 ppm for all readings. These concentrations were below the NPAAQS/ASfiRAE guideline of 9 ppm. The outdoor CO concentrations were also 0 ppm.

Respirable Particulates (PM2 5)

Respirable particulate concentrations* indoors ranged between 11 pg/m^ to 19 pg/m^ with an average of approximately 15 pg/m^. None of the measurements were above the NPAAQS of 65 pg/m^ 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 32 and 36 pg/m^.

In addition to higher efficiency rating filters on their HVAC units, portable High Efficiency Particulate Air (HEPA) purifiers were placed in Rooms 327, 333, 638 and 740. The PM2.5

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