IAQ Building Education and Assessment Model (I-BEAM)

1. [CONTAINMENT AREA] The room with an exhaust is being used as the containment area. A large exhaust machine (negative air machine) keeps the containment area under SIGNIFICANT NEGATIVE PRESSURE. Blocking the supply air is helping to maintain negative pressure. The area is sealed reasonably well from all surrounding spaces (other than the construction area). This is also helping to maintain negative pressure. Construction pollutants are flowing FROM the construction room INTO the containment area and OUT the exhaust.
2. [CONSTRUCTION AREA] The RETURN AIR in this room IS BLOCKED to insure that there is no recirculation of contaminated construction air. The construction area is under negative pressure relative to all surrounding areas except the containment area which draws construction contaminants into the exhaust air stream. Replacement air comes from infiltration, and from adjacent rooms above and below the construction area. An opened window in the construction room is sometimes used to improve the flow of air into the containment area.
3. [OFFICE AREA] The office area is protected against the construction contaminants because it is kept at POSITIVE PRESSURE relative to the containment room, which itself is well sealed. Additional supply air flow to this area during the construction activities can help assure positive pressure and good indoor air quality to the office occupants.

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1. [CONTAINMENT AREA] Inadequate negative pressure in the containment area resulted because the containment area was not adequately sealed, and/or the exhaust fan horsepower was insufficient. There is thus insufficient flow of construction contaminants into the containment area and out the exhaust.
2. [CONSTRUCTION AREA] The RETURN in this area was NOT BLOCKED. Combined with the weak negative pressure in the containment area, some exhaust pollutants escape into the return air stream. Some contaminants also flow through wall cavities and other unplanned pathways to other parts of the building.
3. [OFFICE AREA] Construction contaminants flow through the return air path and through unplanned pathways into the office. Occupants will soon complain.

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1. [CONSTRUCTION AREA] Access to a permanent exhaust port is not available, so a temporary exhaust was provided through a window or other opening in the outside wall. The exhaust is sufficient to insure that the construction area is under significant negative pressure relative to the surrounding spaces, including those above and below the construction area. The RETURN air is BLOCKED. The construction room is sealed sufficiently to insure ADEQUATE NEGATIVE PRESSURE is maintained at all times. If necessary, the supply air may also be blocked so that the construction area is served by transfer air from surrounding spaces in the building.
2. [OFFICE AREA] The office area is well protected from the construction area. Air flows FROM the office area TO the construction area but not vice versa. And no construction contaminants enter through the return air stream.

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1. [CONSTRUCTION ROOM] Someone doesn’t understand pressurization concepts. Construction workers thought they were providing good ventilation by putting a large fan in the window BLOWING FRESH AIR INTO THE CONSTRUCTION AREA. What is this doing? It is pressurizing the construction area, forcing the construction contaminants into surrounding spaces and through the return air stream to other parts of the building. Everyone in the building will be complaining.
2. [OFFICE] Since the construction room is under positive pressure relative to the surrounding spaces, contaminants flow into the office area. Construction pollutants are also contaminating the return air and are being recirculated to all spaces served by this air handling unit.