IAQ: Office Lighting Problems

     AET's building scientists are trained to integrate their investigative methods to the symptoms/IAQ complaints of building occupants. Headaches, nausea, itching/burning eyes are classic IAQ complaints. But, when you add in blurred vision... symptoms may be associated with the office lighting.

     Recent AET IAQ investigations have focused on office lighting as the potential source of building occupant complaints. This is an increasing concern in todays office environment due to the ever increasing number of computer workstations and the different lighting requirements of computer operators from workers who read hard copy documents.

     Recommended light levels for today's office:

• Ambient lighting for computer monitor: 30-50 fc
• Lighting for writing/reading/hardcopy tasks: 75 fc

     Reflections and glare can also interfere with visual comfort when working at a computer. Glare can be caused by:

• Reflections caused by window light
• Reflected light from a glossy wall surface
• Poorly located task light
• Reflected light from a standard downlighting system.

     Proper lighting, workstation positioning, and other ergonomic issues have a significant impact on worker comfort and productivity. Expect to see specific suggestions for improvement in AET's IAQ reports to minimize this frequent but unforseen problem.

ASHRAE Minimum Ventilation Rate

     ASHRAE 62.1-2007 Ventilation for Acceptable IAQ is the preeminent standard used by code officials, HVAC designers and IAQ specialists when evaluating the ventilation rate requirements in commercial and institutional buildings. The 2007 standard provides a minimum combined outdoor ventilation rate of 17 cfm of outdoor air for each occupant within a commercial office space. 

     In AET's IAQ evaluations, the ventilation rate is determined by measuring carbon dioxide levels in the work place. Carbon dioxide (CO₂) is a function of building occupancy; the principal source of CO₂ is the respiration of the occupants. The ventilation rate is calculated by measuring the difference between the maximum indoor CO₂ level and the outdoor level. To meet the ASHRAE protocol, the difference should by less than 700 ppm.

Chinese Drywall Update

    Our February 2009 Newsletter discussed the strong sulfur odor complaints associated with Chinese Drywall installed in SW Florida homes during the years 2004-2006.  The Associated Press reported over 500 million pounds of drywall was potentially used in more than 100,000 homes including houses rebuilt after Hurricane Katrina.

     What's New!  More states are finding this problem and more lawsuits have been filed.  The Consumer Product Safety Commission and the Health Departments of VA, LA, NC, FL, and WA are all investigating.  Reportedly, hydrogen sulfide, sulfuric acid, sulfur dioxide and carbon disulfide have been detected in low (yet unspecified) levels.  In addition to the odors, affected homes have reported blackened/corroded electrical wires, copper piping, silverware and other metals. 

     What Should I Do?  If you purchased a home between 2004-2006 and you smell a sulfur odor:

• Contact your builder and ask him to provide manufacturing information regarding the drywall in your home.
• Check any exposed copper plumbing line for discoloration. 
• Contact your local health department for assistance where your inspection findings warrant.

IAQ INVESTIGATION

A Different Kind of "Tail"

     Recently, AET responded to an IAQ complaint at a financial institution located within a shopping center in New Jersey. Facility occupants reported a "foul, noxious odor" emanating from the rear break room of the facility. AET personnel performed the normal tesing regimen for comfort parameters but also initiated a visual inspection of building finishes and mechanical system.

     While inspecting the ceiling plenum of the complaint area, AET's CIH noted that lay-in ceiling tiles above the area had a strong ammonia odor and observed numerous areas of animal droppings. Further investigation of the fiberglass batting installed below the ceiling deck identified numerous rat nests and large areas of fecal contamination. The client was immediately notified and initiated removal and replacement of the ceiling.

     AET personnel also inspected the exterior of the shopping center and identified the vermin entry point - a "burrow" which was expanded from damage voids within the asphalt and which allowed for infestation on the building side of the exterior envelope. Vermin then traversed the client space (which was used for nesting) to gain entry to the adjacent space, a pizza shop. The client contractor immediately sealed this void and completed the ceiling replacement in the break room and an adjacent storage room.

     Moral of this Story: The term "I smell a rat" is not always figurative and can be literal!.

WHAT'S THAT SMELL?   Eggsactly the right answer

     Dateline: February 2009, CIH notices a faint but noticeable sanitary odor (sulfur smell) emanating from the downstairs laundry room upon entering his home.        

     Response: Use vast IAQ training to find the source

     Possible Sources evaluated as suspect   
     plumbing issue:

• Check main drain line and cleanout.
• Check toilets, sinks and drain traps.
• Check home exterior for evidence of sanitary line breech.
• Contact plumber who also smelled the odor but could not find obvious problem.

     Right Answer: The CIH completely removed every stored, nonmechanical item from the laundry room. At bottom of last item, a wash bucket, were 4 hard boiled eggs given to his daughter by a family relative at Halloween. His daughter had placed the eggs in the bucket and forgot them. The bucket was covered with stored items.

     Moral Of the Story: Good housekeeping is a key component of IAQ. Right answers may be the simplest solution. IAQ investigators must use all of their senses including their sense of humor.

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