Risk Management Indoor Air Quality (IAQ) Tailoring Lease Specifications www.saif.com
Typical protocol for the performance of an IAQ investigation would include an initial walk-through evaluation, personal interviews with the building occupants, environmental monitoring and follow-up site visits. In the initial assessment the complaints are documented, the building and its systems are characterized, followed by an inspection of these systems, with specific attention to the ventilation system. This walk-through also includes a survey of office areas for potential sources of indoor air contaminants. This initial phase is followed up with environmental measurements, based on the findings of the initial walk-through, and concludes with recommendations for the correction and prevention of indoor air quality problems. For a more detailed discussion of this IAQ investigation, readers are directed to a chapter by Patricia Quinlan, et. al. 3
HVAC System Capacities
Based on the experience of the authors and other researchers, it is not uncommon to find that the cause of complaints of poor air quality is simply overloading the HVAC system capacities for which the building has been designed. Many buildings, including owner-occupied buildings, are designed for a given maximum loading based upon the number of persons per square meter (foot) and a maximum quantity of watts per square meter (foot). Exceeding the design capacities is likely to cause temperature control problems (overheating) or indoor air quality problems (not enough ventilation air). These conditions are likely to occur during periods of operation at or near design conditions. Another example would be when a tenant has chosen a high occupant density or installed significant amounts of computer equipment or other heat producing equipment.
The owner may notify the tenant of the design limits of the space, i.e. the maximum number of persons per square meter, or the quantity of watts per square meter.
The space provided for the tenant has been designed to be capable of providing adequate ventilation air to meet ASHRAE Std. 62.1-2004. Guidelines for office type environments specify a maximum density of seven people per 90 square meters (1000 sq. feet), a maximum of one personal computer per person and a maximum of 21 watts per square meter (2 watts per square foot). If tenant needs exceed the office HVAC design capacities, it is the responsibility of the tenant to notify the owner such that appropriate action can be undertaken. The cost of the installation of additional cooling or ventilation capacity if needed can be negotiated.
Another mechanism which could reduce the likelihood of both overheating and air quality problems is to identify equipment known to cause problems.
Clause #10: The space provided for the tenant has been designed to be capable of providing adequate ventilation air to meet ASHRAE
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