IAQ Report Cover Letter, 90 Trinity Place, May 2002

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan May 22, 2002 Indoor Air Quality .Assessment Page 3 H.S. for Leadership & Public Service (M894) ATC Project No. 15-19125-0290

Reai -'I imk Environmental Measurements

ATC collected one hundred and forty (140) sets of real-time environmental measurements consisting of one hundred and twenty-eight (128) in the school building and twelve (12) outdoors. All J'ourteen floors of the school were surveyed. Field data sheets are found in the Attachment. Readings were collected in the morning and evening. The results are described below.

Temperature

Indoor dry bulb temperature measurements ranged from 71.0 °F to 80.1 °F. 'Fhirteen (13) of the indoor measurements for temperature were below and one (1) was above the range of 73 to 79°F (at 50 percent relative humidity) recommended by ASHRAE Standard 55-1992 during the summer season. The outdoor temperature ranged from 65.7 to 69.1 °F.

Relative Humidity

The relative humidity indoors ranged from 24.4 percent to 48.3 percent. Seventy-nine (79) of the indoor measurements for relative humidity were below the ASHRAE-recommended range of 30 to 60 percent for occupant comfort. The outdoor relative humidity range was 21.9 to 27.1 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 549 ppm to 1864 ppm. Twenty-two (22) 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 571 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1271 ppm (background level -t 700 ppm). 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 2 ppm for all collected readings. These concentrations were below the NPAAQS/ASFIRAE guideline of 9 ppm. The outdoor CO concentrations were also 2 ppm for all readings.

Respirable Particulates (PM2,5)

Respirable particulate concentrations* indoors ranged between 6 pg/nP to 16 pg/m^ with an average 11 pghn^- None of the indoor measurements for PM2.5 were above the NPAAQS of 65 pg/m3 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter or above the USEPA recommended concentration of 40 pg/m^ for sensitive individuals such as asthmatic people and children. The outdoor respirable particulate concentrations ranged from 33 pg/m^ to 41 pg/m^ with an average of 36 pg/m^.

CONFIDENTIAL, CITY_21MC100_003464372 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

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