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Deconstructing IAQ

Facilities can benefit from a holistic approach to improving the indoor environment.

By Richard D. Purtell

(IAQ) indoor air quality (Credit: Image provided by Dynamic Graphics, Inc.)

Following the energy crisis of the 1970s, indoor air quality (IAQ) has been a specific focus in the development of standards and building codes in the U.S. and worldwide. At that time, the trick was to find a balance between saving energy (allowing less energy to escape a building) while ensuring that the conservation methods did not adversely affect the quality of indoor air. As buildings became tighter, air filtration systems became more complex…and more critical.

Building standards such as the Model Energy Code (first published in 1983), and its successor, the International Energy Conservation Code (which was developed by the International Code Council, or ICC, in 1998), have included ventilation rate requirements on the up tick as the energy efficiency of buildings has increased over the years.

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) also developed and promulgated Standard 62, Ventilation for Acceptable Indoor Air. ASHRAE standards are the documents that have been most widely used by building engineers and others dealing with indoor environmental issues.

But as facility professionals adapted codes and standards to meet air quality demands, the notion of what IAQ means has also evolved. Today, the focus is, or should be, on the overall indoor environment, not just the air that is breathed.

In the past few years, science and regulatory documents, i.e. standards and codes, have evolved to deal with the indoor environment in a more holistic way. Facility managers (fms) are no longer just dealing with the introduction of outside air, but they must also evaluate the quality of outside air introduced, the elimination of specific contaminants, and many other factors.

The Fortress Effect

With events like 9/11 and the subsequent anthrax attacks in the fall of 2001, security has now become a more vital part of the IAQ equation. Protecting building occupants against potentially harmful or even lethal toxins from the outside air is often a high priority for a fm or building engineer. The great challenge then is to protect those people in the building while still maintaining appropriate fresh air ventilation in order to preserve a healthy and comfortable indoor work environment—not always an easy task.

There are many variables that affect air intake, such as the location of intake grates. In Washington, DC and many other cities, intake grates are often located on sidewalks in front of buildings. In some older buildings, they are even situated near the offloading sections of buildings.

 

This positioning can be undesirable, because it puts intake vents in places where they can potentially capture unhealthy fumes from trucks and other offloading vehicles. Some buildings have begun intaking air from roofs, but that outside rooftop air may lead to higher levels of ozone.

Fms can beef up air intake filtration as part of a building security plan. While this can help protect against toxins and contaminants, the heavy filtration process can also reduce the amount of outside air being circulated through the building, often defeating the purpose.

There are other alternatives, such as installing ultraviolet filtration systems, but they tend to be more expensive and can sometimes be limited by system design considerations. [For more on this subject, read “What To Do When ‘Something Stinks In Here’ by Ronald Cox, which appears below.]

Smart Ways to Improve A Building’s Indoor Environment

The EPA offers these guidelines for employees and facility managers who want to improve their indoor environment (from the EPA publication, An Office Building Occupants Guide to Indoor Air Quality).

• Do not block air vents or grilles;

• Water and maintain office plants properly;

• Dispose of garbage promptly and properly;

• Store food properly;

• Avoid bringing products into the building that could release harmful or bothersome odors or contaminates;

• Keep factors such as air circulation, temperature control, and the pollutant removal function of the HVAC system in mind during placement of furniture and equipment;

• Integrate IAQ concerns into purchasing decisions;

• Develop a preventive IAQ management program;

• Facility managers and building occupants should coordinate in instances when responsibility for design operation and maintenance of the ventilation system is shared;

• These groups should also work together to ensure use of only necessary and appropriate pest control practices and non-chemical methods when possible; and

• Finally, everyone should work together (along with the contractor) before remodels and renovations to identify ways of keeping building occupant exposure to pollutants to a minimum and to ensure that the air distribution system is not disrupted.

 

Finding The Clean In Green

It might seem counterintuitive, but when it comes to a building’s indoor health, “green” air doesn’t always equal clean air. Energy efficient buildings are usually tight buildings with high efficiency windows that allow very little energy to escape. Increased ventilation is often the remedy, but when that air is pulled in from the outside, it must be cooled or heated and humidity must be controlled, which can offset energy savings and increase utility costs.

IAQ research and development currently under way by the U.S. Department of Energy (DOE) is focused on developing new ventilation strategies that simultaneously improve IAQ and reduce the energy impact of increased ventilation. The goals of the DOE’s IAQ project include reducing ventilation energy demands by 50% by 2020 without degrading IAQ, revising and improving ventilation standards and building codes, and enabling energy efficient building practices that have a low risk of creating IAQ problems.

Some of the DOE’s ventilation strategies will concentrate on different ways of improving overall building ventilation. A hybrid ventilation approach is one strategy. This is a combination of natural ventilation systems and mechanical ventilation systems to reduce energy.

Alternatively, task ventilation strategies focus on the part rather than whole, offering personalized ventilation systems that deliver clean air right to the work station. Another option, demand control, focuses on ways to vary ventilation rates depending on occupancy and pollutant sources.

 

Green IAQ Standards

The current emphasis on green buildings has led several relevant organizations to develop multiple standards dealing with the elements of green buildings and green techniques:

• ASHRAE and the U.S. Green Building Council (USGBC) are cooperating on the development of a green building standard for commercial buildings.

• The Green Building Initiative (GBI) is developing a guideline (a standard that is not written in mandatory language suitable for adoption as a building code or mandatory regulation) for commercial buildings.

• American Society for Testing and Materials (ASTM) is developing a standard for sustainable design and construction of commercial buildings.

Many of these initiatives focus on several aspects of the indoor environment, including pest control and maintenance of indoor plants. While it can sometimes be difficult to control what contaminants contractors bring into a building, these new standards may give fms the guidance they need to notify contractors of procedures they must follow any time they are inside or on-site.

Factors That Affect Occupant Comfort And Productivity

The EPA has identified these environmental and personal factors that can affect how people perceive air quality.

• Odors;

• Temperature (too hot or cold);

• Air velocity and movement (too drafty or stuffy);

• Heat or glare from sunlight;

• Glare from ceiling lights, especially on monitor screens;

• Furniture crowding;

• Stress in the workplace or home;

• Feelings about physical aspects of the workplace (location, work environment, availability of natural light and the aesthetics of office design, such as color and style);

• Work place ergonomics, including height and location of computer and adjustability of keyboards and desk chairs;

• Noise and vibration levels; and

• Selection, location, and use of office equipment.

Indoor Pollutants

One of the greatest daily challenges with regard to maintaining a healthy indoor environment is keeping the numerous indoor pollutants in check. Emissions from equipment and furnishings can affect health and comfort on many levels, and the culprits can be found in the essential office equipment and materials that keep a business running. Off gassing of contaminants, fumes from machine operation, and continuous operation of equipment are just a few of the most common causes of indoor pollution.

Even the seemingly innocuous office printer may be a noxious contributor. The August 1, 2007 issue of Environmental Science and Technology reported that a recent Australian study found that nearly 30% of printers tested emitted high levels of ultra fine toner particles, creating a workplace health hazard akin to the dangers associated with cigarette smoke. Although the study sample was small (just 62 printers), it did reiterate the concern that indoor pollutants do not only originate from obvious sources—paint fumes, mold, dust particles.

However, in the August 7, 2007 Time magazine article, “Is Your Printer Making You Sick?” (online at www.time.com/time/health/article/0,8599,1650602,00.html?xid=rss-topstories), Coco Masters notes, “The good news was that 60% of the printers they tested, including eight HP LaserJet 4050 models, four Ricoh Aficio models, and one Toshiba Studio, did not emit any particles. But of the 40% that did, many, such as the HP LaserJet 1320 and 4250 models, were classified as ‘high-level emitters.’”

Creature Comforts

Beyond the essential task of safeguarding building occupants from the health risks associated with indoor pollutants, maintaining a clean and comfortable indoor environment is considered by many to be conducive to productivity and happiness. ASHRAE addresses building comfort in its Standard 55, which deals exclusively with thermal comfort in the indoor environment. Studies by the U.S. Environmental Protection Agency (EPA) have shown that improved IAQ can result in higher productivity and fewer lost work days.

With many Americans spending up to 90% of their time indoors (and many spending most of their working hours in an office environment), the need to create a comfortable and healthy environment is a practical consideration as much as a workplace responsibility.

It’s a mix of direct and indirect factors that affects the overall indoor environment, from moisture and humidity levels to heat or glare from sunlight to odors and noise. Much of it comes down to occupant sensitivity and perception. Indoor plants and flowers may create a pleasant aesthetic experience for some employees but may have adverse affects on those with allergies.

Each person has different sensitivity triggers, and it is impossible to please everyone, but there are steps that can be taken to enhance a building’s overall indoor environment, from the everyday things like disposing of garbage promptly to more sophisticated measures like developing an IAQ management program available to building occupants. Sometimes something as simple as adjusting the humidity level by a notch or two can maintain comfort levels without expending energy by turning up the HVAC system.

In some ways, the perfect indoor environment is the one that goes unnoticed, because it lacks the offending odors, allergens, and temperature variations that distract employees. But fms know that it’s frequently the undetectable pollutants—the infamous odorless, colorless, and tasteless variety—that are often the biggest concern.

Balancing safety, comfort, and energy efficiency is a major challenge. While the goal of attaining the perfect indoor environment may seem elusive, there are practical, easy to implement strategies to ensure that everyone can breathe a little easier…and maybe even work a little more productively.

Purtell (dpurtell@1031nnn.com) is chairman-elect for the Building Owners and Managers Association (BOMA) International and general manager of Triple Net Properties, LLC. For more information, visit www.boma.org.

To request a copy of the printer study, send an e-mail to schwartz@groupc.com.

What To Do When “Something Stinks In Here”

By Ronald Cox, CAFS

Odors and gaseous contaminants can permeate a building, leading to a variety of potential health effects and less than ideal working conditions. Fortunately, most harmful gaseous contaminants can be removed from the breathing air inside buildings with source removal/reduction, proper ventilation, and an effective gas phase air filtration system.

Gaseous Contaminants

The most recognizable form of gaseous contaminants in commercial buildings is odors. But not all gaseous contaminants are detectable by occupants. Gaseous contaminants in commercial buildings may include carbon monoxide, nitrogen oxides, sulfur dioxide, polycyclic aromatic hydrocarbons, human and cooking odors, and carbon dioxide.

Some gaseous contaminants are volatile organic compounds (VOCs). VOCs may be emitted by paints and lacquers, paint strippers and cleaning supplies, pesticides, building materials/furnishings, copiers and printers (note the recent Australian study mentioned in the main article), and craft materials.

According to the U.S. Environmental Protection Agency (EPA), concentrations of many VOCs are two to five times higher indoors than outdoors, and elevated concentrations can persist in the air.

Health effects of VOCs may include:

• Eye, nose, and throat irritation;

• Headaches;

• Loss of coordination;

• Nausea;

• Fatigue;

• Liver, kidney, and nervous system damage; and

• Allergic skin reaction.

These effects can be a drain on personal productivity, may increase absenteeism, and may result in additional medical costs.

Source Reduction And Removal

Pollutant source removal or reduction can resolve IAQ problems related to gaseous contaminants when sources are known and control is feasible. When source removal is not possible or practical, the following steps can be taken to reduce the amount of gaseous contaminants.

• Safely discard partially full containers of old or unneeded chemicals.

• Buy limited quantities of VOC-emitting products.

• Use sealants on all exposed surfaces of paneling and furnishings.

• Allow building materials in new or remodeled areas to off gas before occupancy.

• Adopt integrated pest management techniques to reduce pesticides.

• Store food properly, and dispose of garbage promptly.

Ventilation

One technique for controlling gaseous contaminants is to dilute them with outdoor air. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) has a ventilation standard (62-1989) to provide a minimum of 15 cubic feet per minute (cfm) of outdoor air per person (20 cfm/person in office spaces). Up to 60 cfm/person may be required in some spaces (such as smoking lounges).

Dedicated exhaust ventilation systems isolate and remove contaminants by maintaining negative pressure in the area around the contaminant source. Local exhaust can be linked to a piece of equipment (for instance, a kitchen range) or used to treat an entire room (smoking lounge, rest room, or custodial closet).

Fms should avoid recirculating air from areas that are strong sources of contaminants. Activities that produce odors and gaseous contaminants should be confined to locations maintained under negative pressure. Finally, external vents should be located well away from the fresh air intake of the HVAC system to avoid recontamination.

Gas Phase Air Filtration Credit: Image provided by Kimberly-Clark

Gas Phase Air Filtration

Air filtration is usually most effective when used with source control or ventilation. However, filtration may be the only approach when the pollution source is outside the building, and the gaseous contaminants are brought in through the fresh air ventilation system.

Gas phase filtration may be recommended for:

• Newly constructed buildings;

• Newly remodeled buildings (new wallpaper, paint, carpets, etc.);

• Newly installed furnishings;

• Areas where large volumes of photocopying are conducted;

• Areas where solvents are used (laboratories, nail salons, spas, etc.);

• When employees complain of eye and respiratory irritation; and

• When source control and ventilation control have not resolved odor issues.

Controlling gaseous pollutants requires specialized air filtration products. Traditional particulate air filters—even HEPA filters—are not effective at removing gaseous contaminants.

Most gas phase air filters are made with activated carbon, one of the strongest physical adsorbents known, making it an excellent material for creating a fresh and clean smelling environment. Some filters with activated carbon are dual-layer filters. The upstream layer filters particulates and protects the carbon layer from particulate loading to ensure maximum odor removal. The downstream layer absorbs and retains gaseous contaminants.

In two-stage HVAC filtration systems, particulate pre-filters in the MERV 7 to 8 range protect higher efficiency final filters. In environments with significant gaseous contamination, final filters may be replaced with granular bed or deep pleat carbon filters. If this option is used, the HVAC system must have adequate fan capacity to handle increased airflow restriction.

Typically, gaseous contaminant levels are low to moderate, and single stage pleated gas phase filters may be used. These filters are more expensive than traditional pleated filters, but they remove the entire spectrum of airborne contaminants: particulates and gases. Facility professionals should select a filter that has a particulate filtration level of at least MERV 7 as long as the HVAC system has adequate fan capacity.

With the growing concern about indoor air quality, facility managers should let occupants know that the building’s filtration system has been upgraded to remove particulate and gaseous contaminants. This may be one of the most cost-effective and valuable upgrades a building can make.

Cox (rcox@kcc.com) is a market manager at Roswell, GA-based Kimberly-Clark Filtration Products. For more information on his company’s products, visit www.kcfiltration.com.

 

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