NYC-WTC_000232952

NYC 9/11 Public Portal Document

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Adelaide Associates, LLC 4

Temperature and humldttv are simple physical factors to measure and , understand. However, they are also the source of over 35% of indoor air quality complaints! Though simple in principle, the control of temperature and humidity is key to actual good indoor air quality and the peremption of good air quality.

Low humidity Increases surface static charges which either repel or attract particulate. The charged dust particles can remain suspended longer in air. This creates the condition where the total number of particles in a room may not have changed, just the number airborne. These particles are also of a size and concentration that are usually unmeasurable, in either case.' Low humidity also dries sinus cavities, changes mucous production rates, creates a feeling of pressure in the head (sinus headaches/pressure), and creates dry skin, eye imitation (especially in contact lens wearers), and dehydration.

Elevated humidity decreases surface static charges, and rough surfaces can act as collectors of particles. Elevated humidity also creates the ability for increased microbial growth (mold, fungi and bacteria). Condensation can occur on cold surfaces or cold interfaces (such as uninsulated ductwork, suspended ceiling metal grids, etc.) and create water damage. Odors are more pronounced, and a perception of "not enough fresh air" or "stuffiness" is common.

We found the humidity levels varied throughout the building, between 40 and 65% at all interior locations. Outdoor humidity ranged from 47 to 49%.

Temperature levels within the tested areas varied between 80 to 85 ®F .

Both temperature and humidity levels were elevated, but as mentioned previously once the building systems (HVAC system) are turned on these levels will change.

Photoionizable VOCa were non-detected both indoors and outdoors, and there were no obvious chemical supplies or containers within the space

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CITY_21MC100_011835485

NYC-WTC_000232956