Finding The Answer To Poor IAQ In Schools
The U.S. Environmental Protection Agency (EPA) has ranked indoor air pollution among the nation's top five environmental health risks. The EPA has found that concentrations of indoor contaminants are generally two to five times higher than those of outdoor contaminants.
According to the EPA, nearly one half of America's 115,000 schools have problems linked to poor IAQ.
In the United States, about 55 million people - almost 20 percent of the population - spend their days in elementary and secondary schools. By the time a student graduates from high school, he or she has spent 14,000 hours breathing air inside high school buildings.
Students are at a much greater risk than adults, say many medical experts, since young people are especially susceptible to pollutants.
Furthermore, asthma is one of the leading causes of school absenteeism, accounting for more than 10 million missed school days per year, according to EPA statistics. An estimated 17 million Americans suffer from asthma, nearly 5 million are under age 18. It is the most common chronic childhood disease, affecting more than one child in 20.
Industry Experts Weigh InThe News asked several HVACR manufacturers to identify some of the possible causes of poor IAQ in schools and offer some potential remedies. There were plenty of suggestions.
"Two major causes are insufficient or improperly controlled ventilation and, in certain geographic locations, not having dedicated, properly controlled dehumidification capability, contributing to problems such as elevated CO2 levels, high humidity, mold, and/or elevated VOC [volatile organic compound] levels," said Dick Hanna of the Bard Manufacturing Co., Bryan, Ohio.
Gregg Burnett of Dust Free, Royse City, Texas, stated, "I know from a remediation project here in Royse City that some of the HVAC systems in the schools have quite a bit of age on them and consequently have accumulated a high level of contamination, since the units have not been maintained from an IAQ standpoint."
Chuck Yount of Heat Pipe Technology Inc., Gainesville, Fla., said he was surprised at the measures one school took to introduce outdoor air to the classrooms.
"One school I visited had doors that opened directly to a courtyard," said Yount. "Students were in the class for 45 minutes, and then the door stayed opened for the next 15 minutes for class change: rain or shine, humidity or no humidity. Another I visited had raw outside air entering fancoil units, with only 25 percent run time on the units."
Factoring in outside air requirements, energy conservation measures (elimination of reheat), occupied and unoccupied times (such as nights and weekends), and inadequate maintenance, humidity levels are impossible to control without positive methods to control excess latent heat, stressed Yount.
Doug Steege of RenewAire LLC, Madison, Wis., said some schools lack outdoor air ventilation.
"It is remarkable to realize, in this day and age, the number of unit ventilators that have the outdoor air intakes blocked with sheet metal and a piece of foam insulation, or the number of rooftop units that have the economizer damper plug pulled and taped shut.
"In the name of conservation, this was standard procedure in the late 1970s through the 1980s. Today's IAQ problems are either the direct or indirect consequence of that false logic that said we must minimize the amount of ventilation in order to save energy. For good IAQ, ample, regular outdoor air ventilation is the solution."
Russell Smith of Berner International Corp., New Castle, Pa., listed improper ventilation as one of the two main causes of poor IAQ.
"There really are two main reasons: moisture levels and fresh air," he said. "Moisture needs to be removed from the building in order to prevent mold from growing. In addition, too many times equipment is designed around peak loads when about half of the year it is at part-load conditions. Peak load often causes overcooling and moister conditions.
"Fresh air increases the oxygen content in buildings. When new buildings are designed, they usually are designed with the minimum outside air cfm per person. Also, they are designed with a certain number of people in mind. They rarely are designed with expansion in the equation.
"There are some engineers that do design with two conditions: present and future. Their equipment is bought at future design conditions and then deregulated for present conditions. When loads increase due to occupancy, then they only adjust existing units to comply. The cost for new equipment is higher than bumping to the next size or two up."
Claire L. Barnett, executive director of the Healthy Schools Network, Inc., Albany, N.Y. (www.healthyschools.org), outlined some of the typical reasons for poor school IAQ. However, Barnett was less than optimistic about finding all of the sources that are making schoolchildren sick.
"To my knowledge, no one actually knows the main reason for poor school IAQ," she said. "There are too many causes, not all of which are solved by ventilation. Inadequate, underfunded, or poorly conducted maintenance; poor site location/external pollution sources; poor design and construction, including engineering and ventilation; chemical spills, etc. Without any systematic oversight or reporting on school environments and child health or injury at school, we are all in a fog."
What Can Be DoneIn the eyes of Jane Deming of Friedrich Air Conditioning Co., San Antonio, the HVACR trade is offering products that are designed to offset some IAQ problems, but even these "will not eliminate the need for well-constructed, breathable buildings."
"Specifically, schools in rapidly growing districts frequently use portable buildings to deal with crowding issues," she said. "These structures are typically conditioned by wall-mounted products. The industry is also offering better filters."
Barnett added, "The trade should adopt best practice policies for design and engineering of its products, to allow for natural and mechanical ventilation and systems that are reliable, plus simple to operate and maintain. A well-publicized, accessible code of ethics accompanying every proposal or request for proposal would be useful if it stresses what to look for in a good vendor/service/product."
Yount noted that the HVACR trade normally does not have input into the design of A/C systems in school facilities.
"The HVAC trade does installations based on the engineers' sizing and designs," he said. "After the initial installation, the HVAC contractor is not normally involved in the day-to-day maintenance of the systems. School employees normally do this. Some are qualified and some are not. The solution is to offer the design engineer alternative humidity control solutions, such as packaged dehumidification units or heat pipe enhancement of the air handler."
Meanwhile, Smith noted that systems should be designed to allow loads to be shifted between occupied and unoccupied times.
"With energy recovery systems, you can recover energy, maximize moisture removal, supply neutral conditions, pressurize space, and have total control of space conditions," said Smith. "Schools need systems to be developed to furnish increased amounts of outside air at reasonable tonnages. If people breathe, then all buildings should breathe as well. The industry should be addressing the benefits of increased ventilation and not design around what is the cheapest design methods without addressing IAQ in mind."
Burnett was very specific in his recommendations.
"A mandate from state or federal government, in conjunction with the HVAC-governing entities, to inspect the air-handling units located in educational facilities for issues that would contribute to poor IAQ is a starting point," he said.
"With the price of digital cameras becoming relatively inexpensive, photographs would be included in the inspection. The inspection protocol could contain two sections. The first section would list inspection points common to all HVAC systems, and then a second part would cater to IAQ issues more common for HVAC equipment in that particular region of the country. Obviously the HVACR industry could help craft the inspection protocol.
"Once the data was collected, it could be submitted to the local ASHRAE chapter for review and recommendation at no charge. The local ASHRAE chapter would have a pre-selected committee to perform the reviews and prioritize the responses from a cursory review of the data. The ASHRAE recommendation would then be submitted to the school board for budget analysis.
"If the IAQ problems were immense for a particular school and the tax base could not support the recommended solutions, then a determination of what could be accomplished as steps towards improvement could be identified and implemented while the politicians debated on how to pay for the higher budgetary improvements."
Steege asserted that ventilation rates should not be compromised.
"Just provide the needed ventilation and don't waste time and expense on schemes to reduce ventilation rates or turn ventilation off," he said.
Meanwhile, Hanna asserts that the industry needs to select specific equipment that is capable of providing adequate ventilation and humidity control, along with appropriate controls for regulating temperature and ventilation modes, and humidity where applicable - "all the while affording maximum possible energy conservation."
Mike Lehman, Hanna's co-worker at Bard Manufacturing Co., stated, "Contractors need to develop a complete understanding of the IAQ requirements for the specific applications and any special requirements pertaining to that application. The contractor then needs to have a complete understanding of the manufacturers' equipment capability, including performance, dehumidification, ventilation air, energy recovery capability, and controls and how to apply it to their specific application."
Educating The PublicBarnett said it was time the HVACR trade got on its soapbox and took the story of poor IAQ to the public. "Schools are getting smart about vendors who claim to be there â€˜for the kids,'" she said.
"We need to make sure that industry best practices and codes of ethics are highly visible. We should also publicize horror stories and liability issues and cite federal law on accommodation of all children and staff with disabilities, which can include problems with breathing."
Added Steege, "Clearly communicate the uncompromisable need for ample outdoor air ventilation. Use ASHRAE 62 to calculate and communicate the ventilation rate.
"New schools typically cost between $15,000 and $20,000 per student to construct. Properly sized energy recovery ventilation [ERV] equipment should cost under $100 per student installed - and pay back of this cost many times over the system lifetime. ERVs also have the benefit of moderating the temperature and humidity content of the ventilation air providing additional IAQ advantages."
In Hanna's estimation, the most effective path is to have designated manufacturer sales reps and distributor sales reps work directly with architects, engineers, and school facility personnel, along side the contractor, to properly evaluate the needs, and then to offer the best combination of systems and controls to satisfy those needs.
Lehman agreed. He believed in educating the end users - namely, the school facility personnel - "so that they completely understand how to use the equipment and controls effectively in their day-to-day operation."
In its publication titled "IAQ Design Tools for Schools," the EPA provides both detailed guidance and links to informational resources on school design and repair.
"Having been involved in conversations with various school officials, it has been difficult to get them to understand the importance of controlling humidity in their facilities," said Yount. "Getting the school administration to admit there is a problem is difficult, if not impossible, without legal action."
To Smith, the issue boils down to integrity and cost.
"Contractors and designers must stand behind the systems themselves," he said. "Too many times contractors are money, first - performance, second. They are not the ones that will be handling the equipment for operation and design conditions.
"Owners must demand or be part of the selection process because they will be the ones left holding the bag. It's their building, not the contractors' or designers' building. When the job is finished, they're finished. Further education on various equipment strategies will allow administrators to bridge the gap of misunderstanding."
Concluded Burnett, "Organization of the process is the key. If there were a communication link between the local ASHRAE chapter and local school districts, then the local ASHRAE chapter could organize a trade show, or seminar, consolidated literature, Web site forum, etc.
"Any number of things can be done to provide the local school districts with information. All this activity could be subsidized by participating manufacturers who have an IAQ solution to offer that is recognized by ASHRAE as a legitimate technology."
At the 2004 Air-Conditioning, Heating, Refrigerating Exposition, The News followed a commercial HVACR contractor and a California school administrator as they visited booths at the show. Their mission was to find out about IAQ-related products that the HVACR trade sells and installs every day. Look for a report on their experience in the Feb. 16 issue.
Publication date: 02/09/2004