|Indoor Air Quality Tools for Schools: IAQ Coordinator's Guide.|
|U.S. Environmental Protection Agency, May.|
Some IAQ problems are simple to resolve when school personnel understand the building investigation process. Many potential problems will be prevented if staff and students do their part to maintain good indoor air quality. However, a time may come when outside assistance is needed. For example, professional help might be necessary or desirable in the following situations:
As you prepare to hire professional services for a building investigation, be aware that indoor air quality is a developing area of knowledge. Most individuals working in IAQ received their primary training in other disciplines. It is important to define the scope of work clearly and discuss any potential consultant's proposed approach to the investigation, including plans for coordinating efforts among team members. The school's representatives must exercise vigilance in overseeing diagnostic activities and corrective action. Performance specifications can help to ensure the desired results. Sample performance specification language is italicized.
Other than for lead and asbestos remediation, there are no Federal regulations covering professional services in the general field of indoor air quality, although some disciplines (e.g., engineers, industrial hygienists) whose practitioners work with IAQ problems have licensing and certification requirements. Individuals and groups that offer services in this evolving field should be questioned closely about their related experience and their proposed approach to your problem. In addition, request and contact references.
Local, State, or Federal government agencies (e.g., education, health, or air pollution agencies) may be able to provide expert assistance or direction in solving IAQ problems. If available government agencies do not have personnel with the appropriate skills to assist in solving in your IAQ problem, they may be able to direct you to firms in your area with experience in indoor air quality work. You may also be able to locate potential consultants by looking in the yellow pages (e.g., under "Engineers," "Environmental Services," "Laboratories-Testing," or "Industrial Hygienists"), by asking other schools for referrals, or by calling IAQInfo at . Often, a multi-disciplinary team of professionals is needed to investigate and resolve an IAQ problem. The skills of HVAC engineers and industrial hygienists are typically useful for this type of investigation. Input from other disciplines such as chemistry, architecture, microbiology, or medicine may also be important. If problems other than indoor air quality are involved, experts in lighting, acoustic design, interior design, psychology, or other fields may be helpful in resolving occupant complaints about the indoor environment.
Evaluating Potential Consultants
As with any hiring process, the better you know your own needs, the easier it will be to select individuals or firms to service those needs. The more clearly you can define the project scope, the more likely you are to achieve the desired result without paying for unnecessary services.
An investigation strategy based on evaluating building performance can be used to solve a problem without necessarily identifying a particular chemical compound as the cause. The idea of testing the air to learn whether it is "safe" or "unsafe" is very appealing. However, most existing standards for airborne pollutants were developed for industrial settings, where the majority of occupants are usually healthy adult men.
Some state regulations call for the involvement of a professional engineer for any modifications or additions to a school HVAC system. Whether or not this is legally mandated for your school, the professional engineer's knowledge of air handling, conditioning and sequencing strategies will help to design ventilation systems modifications without creating other problems. In some situations, proper engineering can save energy while improving indoor air quality. An example of this might be the redesign of outside air handling strategies to improve the performance of an economizer cycle.
The guidelines may be of assistance in evaluating potential consultants:
The most important thing for the school's representatives to remember is: Oversee the work and ask questions that will help you assure that the work is properly performed. Specialized measurements of air flows or pre- and post-mitigation contaminant concentrations may be needed to know whether the corrective action is functioning properly.
Performance specifications can be used as part of the contract package to establish critical goals for system design and operation. Performance specifications can be used to force contractors to demonstrate that they have met those goals. At the same, performance specifications should avoid dictating specific design features such as duct sizes and locations, thus leaving HVAC system designers free to apply their professional expertise. When appropriate, you may be able to adapt appropriate sections of the following sample performance specifications for your school.
Outside Air Ventilation: The control system shall be modified and the ventilation system repaired and adjusted as needed to provide outdoor air ventilation during occupied hours. The amount of outdoor air ventilation shall meet ASHRAE Standard 62- minimum recommendations, or shall be the maximum possible with the current air handling equipment, but in no case shall the minimum outdoor air ventilation rate be less than the ventilation guideline in effect at the time the school was constructed.
HVAC System Modifications: When designing the ventilation system modifications, it is important to ensure that: 1) increased outdoor air intake rates do not negatively impact occupant comfort, 2) heating coils do not freeze, and 3) the cooling system can handle the increased enthalpy load. A load analysis shall be performed to determine if the existing heating (or cooling) plant has the capacity to meet the loads imposed by the restored or increased ventilation rates. If the existing plant cannot meet this load or, if for some other reason, it is decided not to use the existing heating system to condition outdoor air, then a heating (or cooling) plant shall be designed for that purpose. The proposal shall include a life-cycle cost analysis of energy conservation options (e.g., economizer cooling, heat recovery ventilation).
Screens: All screens in outdoor air intakes shall be inspected for proper mesh size. Screens with mesh size smaller than ½ inch are subject to clogging; if present, they shall be removed and replaced with larger-size mesh (not so large as to allow birds to enter).
Demonstrating System Performance: The proper operation of control sequence and outdoor air damper operation shall be verified by school personnel or the school's agent after ventilation system modifications and repairs have been completed. This shall include, but not be limited to: observation of damper position for differing settings of low limits stats and room stats, measurement of air pressure at room stats and outdoor air damper actuators, direct measurement of air flow through outdoor air intakes, and direct measurement of air flows at exhaust grilles. The contractor shall provide a written report documenting: 1) test procedures used to evaluate ventilation system performances, 2) test locations, 3) HVAC operating conditions during testing, and 4) findings.
Institutionalizing the Corrective Action: After the ventilation system modifications are completed, school facility operators shall be provided with training and two copies of manual that documents the ventilation system control strategy, operating parameters and maintenance requirements.
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