Indoor air quality report, M833 school, June 2002

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan June 10,2002 Indoor Air Quality Assessment Page 3 H.S. of Economics and Finance (M833)_______ ATC Project No. 15-19125-0291 Real-Time Envikonme.ntal Measurements

ATC collected one hundred and six (106) sets of real-time environmental measurements consisting of ninety-four (94) inside the school building and twelve (12) outdoors. Field data sheets are found in the Attachment. Readings were collected between morning to evening. The results are described below.

Temperature

Indoor dry bulb temperature measurements ranged from 73.6 °F to 80.7 °F. Eleven (11) of the indoor measurements for temperature were above and Eighty three (83) measurement were within the range of 73 °F to 79°F (at 50 percent relative humidity) recommended by ASHRAE Standard 55-1992 during the summer season. The outdoor temperature measurements ranged from 69.4 °F to 72.1 °F.

Relative Humidity

The relative humidity indoors ranged from 39.6 percent to 51.9 percent. All the indoor measurements for relative humidity were within the ASHRAE recommended range of 30 to 60 percent for occupant comfort. The outdoor relative humidity ranged from 43.9 to 47.1 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 440 ppm to 13945 ppm. Five (5) of the indoor measurements for CO2 were above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO2 concentration was 621 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1321 ppm (background level + 700 ppm). The highest concentration (1394 ppm) was recorded on the 4th floor hallway at 5: 49 PM with 2 occupants. 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 ranged from 1 ppm to 3 ppm.

Respirable Particulates (PM2,5)

Respirable particulate concentrations* indoors ranged between 2 pg/m^ to 42 pg/m^ with an average of 12 pg/m^- None of the indoor measurements for respirable particulates were above the NPAAQS of 65 pg/m^ 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter and One (1) of the indoor measurements was above the USEPA recommended concentration of 40 pg/m^ for sensitive individuals and children. The respirable concentrations outdoors ranged between 18 pg/m^ to 46 pg/m^ with an average of 29 pg/m^ •

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