Clearing the Air on IAQ
With an eye on healthcare costs, employee recruitment/retention and a host of other interests, Corporate America is pumping up its employee fitness goals with an array of programs and amenities. Building features such as daylighting, fitness centers, bicycle racks, standing desk stations among other offerings are increasingly being incorporated into both new offices and renovations. Yet one of the most important considerations for workplace wellness is invisible, and right under your nose.
Designers, engineers, builders, owners and developers can stay ahead of the curve by becoming more aware of how indoor air quality (IAQ) supports employee health in the general workplace. MEP Manager Matt Stringfellow recently shed some light on a subject that up until fairly recently has been too often, out of sight, out of mind.
Q: A lot of the new energy code-driven building processes are designed in part with the intent of creating healthier work environments for the occupants. But you’ve noted that this isn’t always the result. What are some of the considerations that hinder the effectiveness of air quality systems?
MATT STRINGFELLOW: I think the emphasis has been on significantly reducing the amount of energy used in a building, which is an important goal. But a key element in creating a healthier work environment is directly related to the amount of outdoor “fresh air” that is brought into the building. More fresh air directly correlates to increased environmental health for building occupants. Unfortunately, increasing the amount of fresh air also can increase the amount of energy a building uses.
Q: Has this always been an issue? Why is this only now coming into awareness?
MATT STRINGFELLOW: It has been a gradual process, in part tied to the evolution in building envelopes. In the past, when buildings walls were not so tight, the air leakage through the walls brought in more fresh air, which actually improved the indoor environmental condition along with the negative impact of using more energy. Now with the tighter envelope requirements, as dictated by the new 2015 Minnesota Energy Code (which adopts the 2012 International Energy Conservation Code), the indoor environment becomes much more critical. It is imperative that the tighter envelopes are correctly installed to prevent heat and cold short-circuit migration through the walls or condensation can result and foster mold growth.
Q: Considering all the building systems, the most expensive to operate is the air exchanges- i.e., bringing fresh air into the building. Is that correct?
MATT STRINGFELLOW: Yes, this is an important point that most people are not aware of. The single greatest use of energy in any building is the amount of energy that is used to heat and cool the outdoor fresh air that is brought into the building.
Q: So isn’t it a temptation for landlords not to operate building systems at optimal (to human occupants) level, in an effort to save money?
MATT STRINGFELLOW: The easiest and fastest way for a building landlord to reduce the energy used in a building is to simply close down the outside air damper where the fresh air is brought into the building and reduce the amount of fresh air. This will instantly reduce the energy use but it will often be at the expense of the comfort and health of the building occupants.
Q: But isn’t that action actually ultimately costing the employer in productivity and healthcare costs?
MATT STRINGFELLOW: This is a very interesting concept to me and one that is starting to trend in business. Most companies spend 1%-2% of their business expense on the cost to operate their buildings where they house their employees. So the remaining business expense of 98%-99% is what they spend on their employee salaries. It simply makes sense that employers would want to take action to maximize the effectiveness and efficiency of their workforce employees in order to optimize the majority of their business expense. It has long been speculated that providing more fresh air into buildings will increase employee cognitive performance.
Q: Instead, the 2:30-3:00 “slump” is a well-known phenomenon in the American workplace. Is this about oxygen?
MATT STRINGFELLOW: When people breathe, they exhale carbon dioxide. If the carbon dioxide level in a building becomes too high or too concentrated, it will cause people to feel tired or even sick and want to lie down. One of the main purposes for bringing outdoor fresh air into a building is to reduce the carbon dioxide level through dilution. It is vital to continuously bring in enough fresh air to maintain the proper dilution rate for the carbon dioxide. When building landlords significantly reduce the fresh air amount below the level required to maintain proper dilution, that is when we have what is called “sick building syndrome” where the interior building environment can actually make employees feel sick. If an office building with daytime hours of operation is not bringing in enough fresh air for proper dilution, the result is that the carbon dioxide concentration will be highest in the middle of the afternoon and this is when the occupants will feel the greatest negative impact.
Q: Are there studies supporting the connection between fresh air and productivity?
MATT STRINGFELLOW: Yes. The Center for Health and the Global Environment at the Harvard T.H. Chan School of Public Health recently completed a study in which volunteer participants spent typical work days in various indoor office space environments with various levels of fresh air being introduced. At the end of each day, the participants were administered a cognitive test to assess their decision making performance. The study results showed marked improvement in cognitive test scores for the participants after spending time in the indoor environments with increased amounts of fresh air. (link to study)
Q: How can we help building designers, engineers, owners, developers, etc. take these factors into consideration when they are planning a new building?
MATT STRINGFELLOW: I really believe the requirements of the new energy code to ensure tight building envelopes, adequate fresh air ventilation, and energy saving measures go a long way in mandating good indoor environments that will support building occupant comfort and good cognitive performance. I think there is a two-fold challenge we need to consider. First is the idea of designing buildings that exceed code-minimum fresh air ventilation rates to further improve comfort and cognitive performance as demonstrated by the Harvard study. Second is the need to educate building operators to avoid the temptation to reduce the fresh air amount to save money on energy use, as this is a very easy thing to do. Regardless of how well a building is designed and constructed, it will only provide a good indoor environment for the occupants if it is operated as intended by the original design parameters.View Comments