Indoor air quality (IAQ) in schools is of particular concern to administrators, teachers and parents. Proper maintenance of acceptable indoor air is more than a "quality" issue, it encompasses safety, liability and stewardship of our investment in the students, staff, and facilities.

Poor IAQ is a known cause of a number of significant adverse health effects, including: rates of infectious disease transmission - influenza, colds, tuberculosis, etc.; Asthma, which affects more than 5% - 10% of the school population; as well as the symptoms of Sick Building Syndrome (SBS), Multiple Chemical Sensitivity (MCS) and Building Related Illnesses (BRI).

[an error occurred while processing this directive]School buildings are very prone to a variety of indoor environment problems that may result in illness symptoms among teachers, staff, and students. School buildings have very high occupant densities and are poorly maintained in many instances. The three major risk factors for school building- related health complaints are inadequate ventilation, surface dust/inadequate cleaning, and mold. All of these can be design and maintenance issues.

Children can be especially susceptible to poor indoor air quality. Because children breathe a greater volume of air relative to their body weight, the same concentration of pollutants can result in higher body burden in children than adults. A child is more susceptible to airborne diseases because their immune system is not as developed as an adult's. Poor ventilation systems contribute to the spread of viruses and bacteria. School children are exposed to more toxins and allergens, which become aerosolized in the classroom.

Schools are not like any other occupied structure

Unlike other buildings, managing schools involves the combined responsibility for public funds and child safety issues, which can emote strong reactions from concerned parents and the general public.

Other aspects include:

• occupant density is higher - with the typical school having approximately four times as many occupants as office buildings for the same amount of floor space
• budgets are tight or insufficient - with maintenance often receiving the largest cuts during budget reductions
• a wide variety of pollutant sources, including art and science supplies, industrial and vocational arts, home economic classes, and gyms
• a large variety of heating, ventilating, and air-conditioning systems - both different types and different models at one site, places an added strain on maintenance staff
• operation and maintenance of each addition is often different as schools add space
• schools sometimes use temporary rooms, portable classrooms, or buildings which were not originally designed to service the unique requirements of schools, nor be occupied by a high density of adults or children

Who Really Cares?

Individual state legislatures have increasingly addressed issues involving IAQ in schools. At least 14 states regulate one or more environmental factors relating to indoor air quality in schools, according to the Environmental Law Institute, 1996.

Indoor air problems can be subtle, and do not always produce easily recognized impacts on health, well being, or the physical plant. In some cases, only one or a few individuals may be strongly affected by what appears on the surface to be psychosomatic in nature because the majority of the school population does not appear to have any symptoms.

At the end of May, significant state legislation was passed in Minnesota that recognizes the vulnerability of our children in school environments. Both houses agreed that positive steps were needed to insure that every new classroom constructed or renovated could be verified to bring in sufficient dilution ventilation air, under all operating conditions.

The revisions to existing statutes require all Minnesota schools built and occupied (or renovations requiring a licensed engineer), put into service after July 1, 2002, to monitor and control outside air intakes and total supply air. School districts in the state may receive revenue, set aside for the state's School Health and Safety program, which has been revised to include indoor air quality. It will provide school districts the earmarked funding to cover the costs for the equipment and systems needed. It will impact all school projects currently in design with completion anticipated for the 2002/2003 school year and beyond. Quote:

Sec. 6. Minnesota Statutes 1998, section 123B.71, subdivision 10, is amended to read: 
Subd. 10. [INDOOR AIR QUALITY.] A school board seeking a review and comment under this section must submit information demonstrating to the commissioner's satisfaction that: (1) indoor air quality issues have been considered; and (2) the architects and engineers designing the facility will have professional liability insurance. Plans submitted under subdivisions 3 and 4 for projects to be placed in service after July 1, 2002, must demonstrate that: (a) the facility's heating, ventilation, and air conditioning systems meet or exceed the standards established by code; and (b) the facility's design will provide the ability for monitoring of outdoor airflow and total airflow of ventilation systems in new school facilities.

Sec. 7. Minnesota Statutes 1998, section 123B.72, subdivision 3, is amended to read: 
Subd. 3. [CERTIFICATION.] Prior to occupying or reoccupying a school facility affected by this section, a school board or its designee shall submit a document prepared by a system inspector to the building official or to the commissioner, verifying that the facility's heating, ventilation, and air conditioning system has been installed and operates according to design specifications and code, according to section 123B.71, subdivision 10, clause (3). A systems inspector shall also verify that the facility's design will provide the ability for monitoring of outdoor airflow and total airflow of ventilation systems in new school facilities ……... EFFECTIVE DATE: This section is effective on July 1, 2002.

"Let's Study the Problem and maybe it will go away."

[an error occurred while processing this directive]The Federal government has opted not to get directly involved in regulating the indoor environment of non-industrial workplaces. The U.S. Occupational Safety and Health Administration (OSHA) will have to wait until the problem exacerbates or the political climate changes. Their 1994 attempt was sidetracked by the big tobacco lobby and the Restaurant Owners Association.

Our national leaders have chosen the politically astute method of addressing the problem: form committees, do surveys and research, start a public education campaign and web site, appoint the "Veep" to head a "green" environmental public relations effort, put the burden back on business to address the IAQ "market" needs; but never address the problem with a direct solution. It is politically easier and much safer for them to let the courts sort it out, after children and workers are injured.

Based on government studies, school buildings have been found to be very prone to a variety of IAQ problems that may result in illness symptoms among the school population.

The U.S. Department of Energy (DOE) concluded that 1 in 5 schools have an IAQ problem. The U.S. Environmental Protection Agency (EPA) identified inadequate ventilation as the primary cause of poor indoor air quality in over 50% of reported cases. Comparative risk studies performed by the EPA and its Science Advisory Board has consistently ranked indoor air pollution among the top five environmental risks to public health.

A 1995 U.S. General Accounting Office (GAO) survey of schools suggests that ventilation and indoor air quality are significant problems. Thirty-six percent of the schools reported HVAC systems as a "less than adequate building feature", while 19% reported existing Indoor Air Quality problems.

When you think about it, these percentages translate into huge numbers, even if you reduce the totals by 50%. This conservatively translates to 4,260,000 students, plus 312,000 teachers spending 6 to 8 hours per day in buildings with IAQ and ventilation problems (1996 enrollment statistics). Of these national totals, 3,072,000 are younger children and at the most risk. …not a good situation.

Good indoor air quality contributes to a favorable learning environment for students, productivity for teachers and staff, and a sense of comfort, health, and well being. These elements combine to assist a school in its core mission - educating children. -- U.S. Environmental Protection Agency

A 1998 Lawrence Berkeley National Laboratories (LBNL) Survey and Critical Review noted, "A significant fraction of these schools may not have ventilation rates high enough to dilute the concentration of bioarerosols that cause infectious diseases such as influenza, colds and tuberculosis. …..Several lines of evidence indicate that inadequate ventilation with outside air is a fairly common problem in schools...." IAQ problems are now the most common complaint made to the California Department of Education.

Of 56 the National Institute of Safety and Health (NIOSH) School Health Hazard Evaluation Reports (HHER) from 1981-1994 included in the LBNL review, 82% identified "insufficient outdoor air to the occupied space" as one of the primary causes of the reported problems. And, a third of the remaining reports indicated that ventilation as questionable. Almost all of the complaints that prompted HHERs were health related. The health complaints were most often the same type that are classified as "sick building syndrome" as defined by the World Health Organization.

Another study in 1989 reported on ventilation measurements in 6 schools in the U.S. Northwest. Ventilation rates, calculated for the whole building volume, ranged from 9.6 to 66.2 cfm/occupant. (The national ventilation standard for classrooms requires a minimum of 15 cfm/person). This average rate overestimates the local ventilation rate of occupied classrooms. In one of the elementary schools, although the whole building ventilation rate was 9.6 cfm/person, an occupied classroom was only 3.4 cfm/person.

This study also highlights the energy costs associated from poor ventilation control. If a rate of 20 cfm/person is considered more than adequate, the schools reported with whole building ventilation rates of 66+ cfm/person are three times the required minimum. This means that three times the amount of outside air is being heated or cooled.

Simple Philosophical Design Solutions may have Large Potential Benefits

Control input errors due to the instrumentation technology employed, product misapplication, inferior installations, and severely -limited budgets can waste huge amounts of on-going operating resources. They cause significant IAQ problems for school buildings. Precise and reliable control is the obvious best way to limit operating energy costs, yet still fully comply with ventilation codes, or the self-determined needs of the building's operations management.

With a "greener" attitude in the selection of furnishings and interior materials, new schools will have a greater chance of avoiding some Indoor Air Quality problems. By reducing the amount of potential pollutant sources we can directly impact the amount of dilution air (outside air) and energy costs needed to overcome their impact on the occupants.

Adequate amounts of dilution air can be provided without energy penalty, simply with more precise control of ventilation rates. A dynamic, continuously adjusting system will provide the greatest payback and flexibility.

New products are being installed across the country in new schools that utilize advanced designs and equipment. Some installations and locations require slightly higher initial HVAC equipment costs, but offer the benefits of providing many more years of lower operating expenses and reduced maintenance requirements, with much greater flexibility in HVAC control as conditions change in the future.

Compact and economical velocity meters are currently available for installation in smaller air handling equipment with outside air intakes, including: unit ventilators, fan coil units, water-source heat pump systems, Energy Recovery Ventilators (ERV's) and desiccant-augmented make-up air units, vertical air conditioners, and the range of smaller packaged roof-top equipment. They can be easily field-installed or ordered as an unpublished option with most air handling equipment.

Sensors are permanently calibrated from the factory for equipment-specific intake conditions, with accuracies better than 2 % of Reading for flows typically ranging between 50 and 800 fpm. Combined with central Direct Digital Control (DDC) hardware, the sensor's electronic output can operate intake dampers, serve as input for return or exhaust flow control and provide school administrators with real-time monitoring and unlimited logging of ventilation rates. These products allow measurement and control of dilution ventilation rates, where historically it was not considered possible or practical.

Improved control of dilution ventilation rates can be implemented without concern for system effects or energy impacts in most of the country, generally those areas without bitterly cold winters and without jungle-level humidity in summers. In these extreme climates, additional preconditioning equipment may be needed to avoid systematic problems and/or help limit energy usage. Regardless of the geographic environment, continuously maintaining codified ventilation rates is still required. But with professional engineering assistance, great results can be competitively accomplished in today's building designs.

In summary

The data from governmental studies underscores the gravity of the problem. And, although not the only aspect of indoor environmental control that needs attention, "ventilation" is the most often cited and the first variable addressed to mitigate problem situations.

Dilution ventilation is necessary for good indoor air quality and is an important component of a healthy indoor environment. It can now be easily achieved with direct, precise control of outside air intake rates. When optimized to minimize energy usage, it will provide a healthy environment at an economically justifiable cost, can help schools provide a safer environment for children and reach their primary goal - quality education. 

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