NYC-WTC_000188511

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan October 12, 2001 Indoor Air Quality Assessment Page 3 Stuvvesant H.S. (M477) ATC Project No. 15-19125-0246

SAMPLING RESULTS

Real-Time Environmental Measurements

ATC collected ninety-six (96) sets of real-time environmental measurements consisting of ninety-four (94) in the school building and two (2) outdoors. These results are described below. Field data sheets are found in Attachment 1.

Temperature

Indoor dry bulb temperature measurements ranged from 70.3 °F to 80.3 °F. Forty-two measurements (44%) were above the range of 69 to 76°F (at 50 percent relative humidity) recommended by ASHRAE Standard 55-1992 during the heating season (wintertime conditions). These readings were on the 6^^, 7th, gth, 9th and lOth floors. The outdoor temperature range was 69.0to71.4°F.

Relative Humidity

The relative humidity indoors ranged from 48.3 percent to 61.9 percent. The 61.9% level was in Room 305, all other measurements were within ASHRAE’s recommended range of 30 to 60 percent for occupant comfort. The outdoor relative humidity range was 51.2 to 59.9 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 449 ppm to 1830 ppm. Fourteen (14) CO2 measurements were at or above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO2 concentration was 365 ppm. Therefore, the acceptable level of CO2 at this location was 1065 ppm (background level ■+• 700 ppm). Rooms with high CO2 levels were found on all floors except the 9^^ floor. 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 - 1 ppm for all readings. These concentrations were below the NPAAQS/ASHRAE guideline of 9 ppm. The outdoor CO concentration was 0 - 2 ppm.

Respirable Particulates

Respirable particulate concentrations indoors ranged between 18 pg/m^ and 43 pg/m^. All concentrations were below the NPAAQS/ASHRAE guideline of 50 pg/m^ (annual average concentration of particulate matter 10 micrometers or less in aerodynamic diameter). The outdoor respirable particulate concentration range was 33 to 42 pg/m^.

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