Indoor air quality report for PS 234M, Feb 2002

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan February 8, 2002 i ndoor Air Quality Assessment Page 3 P. S. 234M ATC Project No. 15-19125-0279

Real-Time Environmental Measurements

ATC collected sixty (60) sets of real-time environmental measurements consisting of fifty (50) from inside the school building and ten (10) outdoors. All three floors of the school were surveyed. These results are described below.

Field data sheets are found in Attachment 1. Readings began at 10;00 A.M. and concluded after 12:55 P.M.

Temperature

Indoor dry bulb temperature measurements ranged from 67.1 °F to 75.0 °F. Three (3) measurements were below the range of 68 to 75°F (at 50 percent relative humidity) as recommended by ASllRAE Standard 55-1992 during the heating season (wintertime conditions). The outdoor temperature measurements ranged from 38.6 to 41.0 °F.

Relative Humidity^

The relative humidity indoors ranged from 18.9 percent to 35.5 percent. Twelve (12) of the measurements were within the ASITRAE-recommended range of 30 to 60 percent for occupant comfort. All other measurements were below the recommended range. The outdoor relative humidity ranged from 43.1 to 46.9 percent.

Carbou Dioxide Concentration

Carbon dioxade concentrations indoors ranged from 544 ppm to 3102 ppm. Fourteen (14) CO2 measurement was above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The maximum outdoor (background) CO2 concentration was 503 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1203 ppm (background level + 700 ppm). The highest measurement was recorded in room 315. At the time of ATC’s assessment room 315 was occupied by 36 people. 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 to 1 ppm for all readings. These concentrations were below the NPAAQS/ASHRAE guideline of 9 ppm. The outdoor CO concentrations ranged from 0 to 1 ppm.

Respirable Particulates tPM2,5}

Respirable particulate concentrations* indoors ranged between 21 pg/in^ to 42 pg/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 average PM2.5 concentration for the entire school building was approximately 34 pg/m^. This average concentration was below the USEPA recommended concentration for sensitive individuals such

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