NYC-WTC_000197574

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan November 26. 2001 Indoor Air Quality .Assessment Page 3 Stu\vesant Hiuh School (.M477) ATC Project No. 15-19125-0246

REAL-TIMEJ^’IRONMENTAL MEASUREMENTS

ATC collected one hundred and twenty (120) sets of real-time environmental measurements consisting of one hundred and eighteen (1 18) 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 I. Readings began at 9:15 A.M. and concluded after 2:10 P.M.

Temperature

Indoor dry bulb temperature measurements ranged from 70.6 °F to 79.2 °F. Eighty-five (85) measurements were above the range of 68 to 75°F (at 50 percent relative humidity) recommended by ASHRAE Standard 55-1992 during the heating season (wintertime conditions). These measurements were collected throughout the school building. The outdoor temperature range was 62.1 to 66.9 °F.

Relative Humidity^

The relative humidity indoors ranged from 38.3 percent to 66.5 percent. Three (3) measurements were above the ASHRAE-recommended range of 30 to 60 percent for occupant comfort. The outdoor relative humidity range was 38.8 and 50.8 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 501 ppm to 1696 ppm. Seventeen (17) COy measurements were above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) COy concentrations were 435 ppm and 480 ppm. Therefore, the maximum acceptable level of COy at this location was 1135 ppm (background level + 700 ppm). The highest reading, 1696 ppm, was in Room 125. Rooms with CO2 levels above the recommended maximum were found on the pt, 3rd, 4th, 5th. gth, 7th, gth and ;oth floors. 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 COy indoors is occupant respiration.

Carbon Monoxide Concentration

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

Respirable Particiilates (PM2,p}

Respirable particulate concentrations* indoors ranged between 15 (Xg/m^ to 63 pig/m^. All measurements were below the NPAAQS of 65 pg/m^ 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter. The outdoor respirable particulate concentrations were 29 and 73 ug/mA

CITY_21MC100_003046098

NYC-WTC_000197576