(Mouse over the pictures to see "Hot Spots" that reveal messages which are referenced in more detail.)
|1. Pollutants Travel Through Plumbing Chases
||2. Pollutants Travel Through Wire Chases
Remember...“All cavities in the walls, ceilings or floors around pipes should be sealed.”
(Hot Spot on area beneath the sink around the pipes)
- Plumbing chases are hidden pathways for contaminants to travel from one area to another.
- Improperly sealed wall cavity around plumbing fixtures in kitchens, bathrooms, and HVAC equipment act as highways for bathroom effluents, cooking odors, pesticides, sewer gases, basement mold, underground garage exhaust, and other contaminants.
- Such cavities also undermine attempt to control room pressure. Solutions to these problems may simply require that such cavities be sealed.
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Remember...“Pollutants can travel through wire chases and contaminate other parts of the building.”
(Hot Spot around pollution flow, receptacle, and wire chase.)
- Any cavities in the wall or ceiling of a room with significant pollution sources should be minimized.
- In the dramatized picture below, laboratory chemicals are being unintentionally drawn into the wire chase and contaminating the spaces above.
- Dust accumulation around any electrical receptacle cover is a sign that air (and possibly pollution) is being drawn into the wire chase through the receptacle cavity.
Remember...“Occupant complaints may be caused by sources of pollution in other parts of the building”.
- Understanding how pollutants travel through unplanned pathways is a critical aspect of diagnosing indoor air quality problems.
|3. Stairwells and Elevators are Common Pathways
||4. Plan the Flow Path of Pollutants Correctly
Remember...“Pollutants may travel up stairwells and elevator shafts into occupied spaces.”
(Hot Spot over the stairs and encompassing the smoke, but not the person.)
- The smoker in this picture may think that smoking in the stairwell has the same effect as smoking outside. But pollutants can migrate from lower floors to upper floors through stairwells and elevator shafts.
- It is not unusual, for example, to find the high concentration of soil gases such as radon not only in the basement, but also and at the op of the elevator shaft or stairwell.
- Stairwells should be kept clean and free of pollution sources.
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(Hot Spot on large area over occupant, pollution plume, and exhaust
- Ask Yourself...“What’s the matter with this picture?”
- Did you notice that the copy machine is positioned so that the occupant is in the direct path of the pollutants as they travel from the copy machine to the exhaust? What would you do to correct the problem?
|5. The HVAC System Transports Air Pollution
||6. Dust Accumulation and Air Movement
Remember...“The HVAC System is a major transport device for both air and pollution in a building.”
(Hot Spot over HVAC system connecting the rooms.)
- Any pollution source in one part of the building may become a problem to other parts of the building served by the same air handler, as the pollution travels through the return air stream and recycles as part of the supply air through the air handling system.
- In the picture, the smoke from a private office travels to unwitting recipients elsewhere in the building.
Remember...“Where dust accumulates in air passageways are clues to the direction of flow.”
(Hot Spot over the hinge.)
- As air moves through openings it often collects on protruding surfaces. Check door hinges, door frames, around electrical receptacle covers, grilles, and other similar locations for accumulated dust.
- The dust side of the surface is the direction from which the air is moving.