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NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan October 19. 2001 Indoor Air (Quality Assessment Page 3 StLA'vesant Hiuh School (.M477) ATC Proiect No. 15-19125-0246

SAMPLING RESULTS

Real-Time Eaa ironmestal Measurements

ATC collected one hundred and five (105) sets of real-time environmental measurements consisting of one hundred and three (103) in the school building and two (2) outdoors. These results are described below. Field data sheets are found in Attachment 1.

Tempera,'we

Indoor dry bulb temperature measurements ranged from 70.3 °F to 79.0 °F. Eight (8) measurements were above the range of 69 to 76°F (at 50 percent relative humidity) recommended by ASHRAE Standard 55-1992 during the heating season (w'intertime conditions). These readings were on the l^Q 4^1'’, 5th apcj 5th floors. The outdoor temperature range was 51.4 to 60.9 °F.

Rekilh’e Hiimidi/v

The relative humidity indoors ranged from 24.0 percent to 45.1 percent. Seventy-four (74) measurements were below the ASHRAE's recommended range of 30 to 60 percent for occupant comfort. These readings were collected throughout the school building. The outdoor relative humidity range was 24.0 to 48.0 percent.

Carbon Dioxide ConcenTration

Carbon dioxide concentrations indoors ranged from 419 ppm to 2498 ppm. Ten (10) CO? measurements were above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) COy concentration was 349 ppm. Therefore, the acceptable level of COg at this location was 1049 ppm (background level + 700 ppm). Rooms with high CO? levels were found on the 2''"^, 3''^^, 4llC 6'1'’. 73b and lO^b 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 COg indoors is occupant respiration.

Carbon MonoxideConcentrati^

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

Respirabie Tcirricuialei-

Respirable particulate concentrations indoors ranged between 4 iig/m^ and 26 (.Lg/m^. All concentrations were below the NPAAQS/ASHRAE guideline of 50 ugdn^ (annual average concentration of particulate matter 10 micrometers or less in aerodynamic diameter). The outdoor respirable particulate concentration range was 9 to 14 ughnA

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