CAL-IN's engineers offer comprehensive indoor air quality investigations and solutions that contain the following elements:

Symptom Description
CAL-IN defines the problem via occupant interviews or by written questionnaires during the initial walk through of the building, the building ventilation system, and adjacent outdoor locations, during which we collect a detailed inventory of potential sources of contaminants.

Potential Source Inspection
During the walk through, CAL-IN also investigates whether there is any potential of exposure to contaminants associated with previous usage of the building. In cases of closed military bases or firing ranges, contaminants such as asbestos or lead have been encountered during the renovation process. Contaminants arising from indoor sources, parking garages, loading docks, and underground areas are also inspected.

Ventilation System Inspection
CAL-IN's air contaminant measurements include assessing the amount of outside air being delivered into the building as well as humidity, temperature and dew point. It is important to measure outside air delivery during the time of the contaminant measurement to ensure the accuracy of the reading, which could result in a false positive that would adversely affect the diagnosis and mitigation plan.

Contaminant Measurements
CAL-IN offers comprehensive building inspections that are in alignment with the physical symptoms reported by building occupants. After a careful review of the potential indoor sources that may be contributing to the occurrence of the reported occupant complaints, sampling and analytical protocols are employed during measurement. CAL-IN refers to the EPA's 1990 "Compendium of Methods for the Determination of Air Pollutants in Indoor Air" which describes methods for measuring nine different classes of pollutants at concentrations commonly encountered in indoor air. ASTM Committee D-22 on Sampling and Analysis of Atmospheres as also published recommended sampling and analytical methods specifically for indoor air. 
 
Data Interpretation & Analysis
CAL-IN gathers all pertinent inspections and measurement information and prepares an analysis of the problem, which is used to formulate the mitigation recommendation. 
 
Mitigation Recommendations
CAL-IN designs and builds HVAC systems that include a number of options (i.e., filtration, dehumidification, humidification, fans, heating, ionizers, uv lights, etc.). Together, we work with subcontractors who install the system to ensure that the equipment is running according to how it was designed. Once the mitigation is complete, a post-mitigation analysis is conducted to measure the effectiveness of the strategy employed. If challenges still persist, additional testing and analysis may be required.

Reports and Studies
CAL-IN's Indoor air Quality (IAQ) expertise is in the field of applied science concerned with controlling the quality of air inside buildings and other enclosures (tunnels, etc.) to ensure healthy conditions for workers and the public, and a clean environment for the manufacture of products. While indoor air pollution is of primary concern, other factors such as noise, temperature, and odors also contribute to the quality of indoor air. To claim that all airborne contaminants can be eliminated from the indoor environment is naive and unachievable. More to the point and within the realm of achievement is the goal of controlling contaminant exposure within prescribed limits. To accomplish this goal, CAL-IN's engineers are highly skilled and trained in the movement of particulate and gaseous contaminants in quantitive terms that take into account:

• the spatial and temporal rate at which contaminants are generated and emitted
• the velocity field of air in the indoor environment
• the spatial relationship between source and workers, and the openings through which air is withdrawn or added
• exposure limits (time-concentration relationships) that define unhealthy conditions

Goals
CAL-IN's objective is to establish fundamental quantitiative relationshps that address the generation of particulate and gaseous contaminants that govern movement in the indoor environment. Established in our client relationships, these objectives become the tools with which our designers predict contaminant exposure.

It is assumed that the engineers with whom we partner are familiar with the fundamentals of calculus, vector notation, thermodynamics, fluid mechanics, mass transfer, and heat transfer. A background in numerical computation is not required, although many of the key support relationships involve briefing our clients on such computations.

There is a sizeable body of information on indoor air quality control. Many books have been written in which the conclusions and recommendations, while useful, fail to address the subject with the organization, scientific foundation, and analytical and mathematical rigor expected of today's engineers. For example, CAL-IN engineers are often asked to predict the performance of ventialation systems to ensure that they satisfy government or more stringent company standards, prior to constructing and testing the entire system. The design of a ventilation system requires making decisions in several stages:

1. Identify the contaminants and understand their effects on health
2. Select the maximum exposure limits that will be used as design criteria and standards to judge the system's performance
3. Design the "hood" and select the volumetric flow rates of exhaust (captured) air, recirculated air, and make-up air
4. Deisgn the duct system, select the fans, and compute the operational costs
5. Select the bas cleaning device to remove contaminants from the caputured air before discharge to the outside environment or recirculation to the indoor environment
6. Conduct laboratory experiments of the ventilation system, test the full scale system in the field, and sample the air in the vicinity of the source and workers to ensure that item (2) above is satisfied

Presently the body of knowledge on these subjects consists mostly of general design guidelines that lack precision and detail. For example, present practices provide no way to estimate the mass concentration (c(x,y,z,t) at locations where workers are apt to be stationed. Thus, when a process produces contaminants, it is difficult to determine whether installation of a control system is necessary. Furthermore, if a control system is installed, it is difficult to determine whether it reduces concentrations to safe levels.

CAL-IN thus considers it a prudent responsiblity to be able to accurately make these predictions and include them as integral steps in the design of products, systems, or processes. We do not believe that we can afford to examine health and safety considerations after a design has been completed, and then to modify the design to satisfy the considerations by costly cycles of testing and retrofit.
As a result of our adherence to the highest quality standards, we instruct private industry as well as the public sector in:

• medical, economic, regulatory, and professional aspects of indoor air quality control
• contemporary engineering practices
• bodies of knowledge available in other disciplines that can be used to predict contaminant concentrations
• developments in computational fluid dynamics (CFD), which is a useful tool for indoor air quality engineering

IAQ Presentation-Commercial Buildings 
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