Indoor air quality report, M477 School, March 2002

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan March 7, 2002 Indoor Air Quality Measurements Page 3 Stuwesant Hieh School fM477') ATC Project No. 15-19125-0246

Real-Time Environmental Measurements

ATC collected one hundred and twenty (120) sets of real-time environmental measurements consisting of one hundred and eighteen (118) 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 1. Readings began at 8:00 A.M. and concluded after 12:40 P.M.

Temperature

Indoor dry bulb temperature measurements ranged from 68.1°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 conditions). The outdoor temperature range was 45.8 to 49.4 °F.

Relative Humidity

The relative humidity indoors ranged from 21.8 percent to 27.4 percent. All measurements were below the ASHRAE-recommended range of 30 to 60 percent for occupant comfort.. The outdoor relative humidity levels were 26.7 and 28.2 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 526 ppm to 1196 ppm. All of the CO2 measurements were within the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO2 concentrations were 521 and 578 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1278 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/ASHRAE guideline of 9 ppm. The outdoor CO concentrations were 1 ppm.

Respirable Particulates (PM2_ 5)

Respirable particulate concentrations* indoors ranged between 4 pg/m^ to 19 pg/m^ with an average of approximately 10 pg/m^. None of the measurements were above the NPAAQS of 65 pg/m3 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter or the USEPA recommendation of 40 g/m^ for sensitive individuals and children. The outdoor respirable particulate concentrations were 29 and 32 pg/m^.

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