NYC-WTC_000200217

NYC 9/11 Public Portal Document

Mr. Bernard P, OrIan October 30, 2001 Indoor Air Quality Assessment Page 3 Manhattan Acad, of Technology @. P.S. 2M ATC Project No. 15-19125-0273

TABLE 2 REAL-TIME MEASUREMENTS Location Temperature Relative Carbon Carboui Respirable ('’F) Huiniditv Dioxide Monoxide Particulates I (%) ’

(ppm) (w.») Staircase 4 & 5 76.8 71.6 1240 2 103 Office 301 76.9 70.5 1275 2 67 Hallway outside room 77.3 69.5 1043 1 80 303 Room 303 77.8 69.0 1290 1 -97 Room 306 77.8 68.1 935 1 72 Room 305 77.8 66.0 946 2 66 Room 308 77.9 62.1 1764 2 62 Room 309 78.4 68.1' 1423 1 74 Staircase / Exit 6 78.8 68.9 948 1 110 Room 318 79.2 69.3 1120 1 112 Outdoors 77.8 64.1 506 1 86

Temperature

Indoor dry bulb temperature measurements ranged from 76.8 °F to 79.2 °F. All 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 (wintenime conditions). The outdoor temperature was 77.8°F.

Relative Humidity

The relative humidity indoors ranged from 62.1 percent to 71.6 percent. All of ths indoor measurements were above the ASHRAE’s recommended range of 30 to 60 percent for occupant comfort. The outdoor relative humidity was 64.1 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 935 ppm to 1764 ppm. Six (6) CO2 measurements were above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO? concentration was 410 ppm. Therefore, the acceptable level of CO2 at this location was 1,110 ppm (background level 4- 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 CO? indoors is occupant respiration.

Carbon Monoxide Concentration

Carbon monoxide concentrarions indoors were 1-2 ppm. These concentrations were below the NP.XAQS/ASHRAE guideline of 9 ppm. The outdoor CO concentration was 1 ppm.

CITY_21MC100_011274464

NYC-WTC_000200219