Cover letter for indoor air quality assessment, Dept of Education

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan October 29, 2001 Indoor Air Q)iiality Assessment Page 3 SiLivvesant Hiah School /M477) ATC Project No. 15-19125-0246

Real-Time Environmental Measurements

ATC collected ninety-nine (99) sets of real-time environmental measurements consisting of ninety-seven (97) 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 8:00 A.M. and concluded after 1:00 P.M.

Tciiipcraliire

Indoor dry bulb temperature measurements ranged from 67.6 °F to 75.7 °F. Only one (1) measurement was below the range of 69 to 76°F (at 50 percent relative humidity) recommended by ASHRAE Standard 55-1992 during the heating season (wintertime conditions). This measurement was collected from the theater. The outdoor temperature range was 57.0 to 59.7 °F. ■

Re/alive Hiirmdify

The relative humidity indoors ranged from 19.4 percent to 72.8 percent. Only two (2) measurements were within the ASHRAE-recommended range of 30 to 60 percent for occupant comfort. All other measurements were below the recommended range except the reading collected from room 901 which it was above the recommended range of 69 to 76°F. The outdoor relative humidity range was 18.5 to 25.5 percent.

Carbon Dioxide Concent.ralion

Carbon dioxide concentrations indoors ranged from 356 ppm to 1260 ppm. Five (5) CO2 measurements were above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO2 concentration was 350 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1050 ppm (background level + 700 ppm). The highest reading, 1260 ppm, was in Room 738. Rooms with COg levels above the recommended maximum were found on 4^1, 6th, 7th and IQth 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 CO2 indoors is occupant respiration.

C^bon Adonoxide Concenlralion

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

Respirable Particu/aiei- (PA‘f2,§}

Respirable particulate concentrations indoors ranged between 9 pg/m^ and 28 pg/mA None of the measurements was above the NPAAQS of 65 pg/nP 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter. The outdoor respirable particulate concentration range was 21 to 33 pg/m-’.

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