Thermal Comfort: A Fresh Look at an Old Issue, Part 1

For those owning, designing, building and furnishing workplaces, thermal comfort has newfound significance.

Studies link thermal comfort and physical effects of uncomfortable temperatures with how workers perform, including conditions where decision-making suffers. The conversation is reaching an audience that can make it happen: building owners.

A 2016 Dodge Report on healthy buildings said 64% of owners and clients desire better air quality in their buildings, and 62% want enhanced thermal comfort. The reason? Competition for the best talent continues to grow more intense, and superior thermal comfort leads to happier, more fully engaged employees. Talent recruitment and retention is one pillar of the business case for thermal comfort, and it’s lending encouragement to innovators to help achieve it.

In simple terms, everyone is thermally uncomfortable to some extent. Successfully managing thermal comfort integrates an understanding of how workers sense temperature and the ways of controlling temperature where they are working.

The background, current state, and predictions for enhancing thermal comfort in the workplace are among the topics of this two-part story. Like other workplace issues, progress in this area is happening. However, its rate has only quickened recently.

The ideas about workplace conditions affecting human health fill the studies of Italy’s Dr. Bernardino Ramazzini. His credits include systematic investigations into links between work and diseases affecting worker wellness and comfort. Dr. Ramazzini observed conditions experienced by “learned workers” and suggested remedies in his writings for symptoms he believed were work related. These included headaches, obesity, and problems with breathing, vision and muscle soreness.

Today these symptoms would indicate Sick Building Syndrome. However, no such nomenclature existed over 300 years ago when Dr. Ramazzini made his recommendations. His book, “De morbis artificum diatriba” (Diseases of Workers), was published in 1700.

In their 2001 review of “Diatriba,” Škrobonja and Kontošić, two members of the medical faculty at Croatia’s University of Rijeka wrote that Dr. Ramazzini “masterfully” contemplates linkage between work and human health, investigating connections of harmful environmental factors and occupational diseases. Škrobonja and Kontošić concluded that, “Even 300 years after the first publication of ‘Diatriba,’ Ramazzini is still relevant.”

Considering advancements made in the last 317 years, it is unlikely that Dr. Ramazzini would find mercury poisoning among workers making mirrors, or lead poisoning among potters. Something he could observe is today’s knowledge workers remain exposed to variations of comfort problems faced by the “learned workers” of his day. Chief among the lingering issues is thermal comfort.

Not that thermal comfort issues have gone unnoticed, but solutions for other airborne problems took priority. An important bellwether came in 1985.

In that year BOSTI released its study entitled “Using Office Design to Increase Productivity.” BOSTI researched 10,000 workers in 100 organizations, resulting in a finding that “workplace design affects productivity and job satisfaction.” They gauged worker comfort by “their capacity to work for long periods of time at their work surface.” Thermal comfort’s discussion comes in the comfort chapter’s next-to-last bullet point: “Being too warm or cool or having a temperature which fluctuates” relates to workers’ lowered perception of workplace comfort.

Although the words “workplace” and “comfort” rarely appeared in the same sentence in the mid-80s, Rani Lueder,  author of the 1986 book, “The Ergonomics Payoff: Designing the Electronic Office,” voiced concerns about the quality of air in the “physical environment.” She wrote that, “Energy conservation, which has reduced the frequency of air changes in the office and introduced new chemicals whose effect are not yet known, has generated concern.” She made a two-pronged argument. First, unknowns about air quality existed in the places where people spend one-third of their day. Second, “the open-plan systems created ‘dead air’ spaces which increase the potential for thermal discomfort.”

Ms. Lueder included comments about heat gain in the office from the “concentrations of electronic equipment” of the day. This concentration contributed to fluctuating temperatures, which was a discomfort factor also mentioned in the BOSTI study. In her book, Ms. Lueder suggests zoned air conditioning as a solution to some of the issues she raised.

Fortunately for office workers, the decade of the 90s saw a series of actions to improve air quality inside buildings. Three letters set the ball rolling. They were ‘SBS.’

Ms. Lueder’s concerns about ‘unknowns’ in the air workers breathed inside typical 80s-era buildings proved correct. Workers were getting sick, absenteeism was rising, and the cause was unclear. Seemingly random sets of symptoms defined most cases: stuffy sinuses, dry eyes, dry throat, skin irritations, headaches and poor concentration due to tiredness. More mysterious still was that these symptoms worsened during the workday, eased in the evening and might disappear on long weekends or holidays.

“Sick Building Syndrome” (SBS) was the name given to the mystery disease by the Commission of the European Communities. In its 1989 report, the Commission stated that SBS “is a set of varied symptoms experienced predominantly by people working in air-conditioned buildings.” They sized up the dimensions of the challenge SBS presented by stating “diagnosis is by exclusion” of every other possible illness and that “the cause is probably multifactorial.”

As if SBS alone was not enough of a problem confronting the A&D community, the European report added that, “The use of synthetic materials which emit various chemical substances has led to an increase in the concentrations of indoor pollutants.” The report found that as temperatures inside buildings rose, so did the release of pollutants from furnishings and other sources.

The State of California acted with legislation in the early 90s. Responding to the indoor air quality work initiated by the state’s Air Resources Board, the Department of Health Services prepared rules for controlling volatile organic compounds (VOCs) in buildings.

“The levels of pollutants in some buildings are 100 times higher than outdoors.” That quote from Robert Axelrad, the director of the EPA’s indoor air division, appeared in the July 2, 1990, issue of Fortune Magazine. The Fortune Magazine story about Sick Building Syndrome, written by Faye Rice, contained a prediction from a New Canaan, CT, architectural designer: “The major paint and carpet companies will get smart one day and make their own lines of environmentally safe products.” His advice to clients in 1990: “Safeguard against sick building syndrome by using low-toxicity building materials.”

These indoor air quality developments did nothing to address thermal comfort. Credible evidence of temperature either stimulating or suppressing SBS did not exist.

Improvements in indoor air quality marched ahead, with smoking banned in federal buildings in 1997. This move followed smoking bans on flights of six hours of less in 1990 and those of two hours or less in 1988 in the skies over the United States. The UK issued their smoking bans in buildings and aircraft around the same time, as well as issuing guidance to employers about thermal comfort.

In a 12-page document, the Health & Safety Executive (HSE) suggested thermal comfort is “very difficult” to define; it is affected by some variables that are outside an employer’s influence, and the best step is to make a start and keep trying. Recommendations to employers included assessing thermal comfort by combining the effects of air temperature, humidity and air movement into a single measurement, understanding that different people react to temperature in a variety of ways, and realizing that different areas of the buildings may require different temperatures. All spaces, they contended, need fresh air circulation. Though published in 1999, the HSE established individual tenants of thermal comfort that remain valid.

Many initiatives begun in the 90s supported the premise that buildings could be healthier for workers and likely more energy efficient in the bargain. Was it merely a matter of establishing best practices, of assembling an approach to indoor air quality, energy efficiency and not only healthier workers but ones that were happier, too? Perhaps the U.S. Green Building Council had some of this in mind as they launched LEED in 2000.

Leadership in Energy and Environmental Design (LEED), to borrow a show business cliché, is a program that needs no introduction. Many successes, many certifications, many recognitions punctuate its 17-year history. That tens of thousands of buildings have energy efficient designs, sustainable materials, more daylight and more fresh air is praise-worthy. Lauded as LEED is, a research team found less than hoped-for success in how green LEED buildings provide comfort to their occupants.

Researchers Hedge, Miller and Dorsey acknowledge LEED’s inclusion of an ergonomic workplace credit, along with the fact that only a handful of applications incorporated it as of their study’s publication in 2013. Around that same time, USGBC was setting a strategic focus on supporting human health.

For their study, Hedge et al. performed what they termed a retrospective post-occupancy evaluation survey of 319 occupants. Those surveyed worked in one of three buildings at Edmonton’s University of Alberta; two designed for LEED Silver certification and one conventional building with limited green features.

In writing their conclusions, the researchers found occupants favored green buildings and their healthy interiors over conventional buildings but did not rate them higher on their comfort or find them more productive places to work. This finding led the researchers to observe that acoustics, privacy and ergonomic workstations receive no greater attention in a green building than a conventional one.

While buildings might be as green as Ireland’s Connemara countryside, their occupants may cite a familiar list of unaddressed needs. Hedge, Miller and Dorsey reference a 2013 study of occupants in two LEED Platinum buildings who bestowed high ratings in health, performance and satisfaction. At the same time, they mentioned problems of too much temperature variation, concerns for air freshness and quality, distracting noises and musculoskeletal symptoms. Occupants associated the latter with shortcomings in workstation ergonomics.

Unrelated to LEED, Li, Zhiwei and Li asserted that thermal discomfort via high or low air temperature had adverse effects on worker productivity. In framing the variables of their 2010 study, they determined indoor environmental quality (IEQ) primarily included heat, cold, noise and light. As to the constituents of productivity, the researchers assessed four classes of functions: perception, learning and memory, thinking, and executive functions. Li et al. wrote that, “warm discomfort negatively affected participants’ well-being” and increased heart rate variation, and in moderately uncomfortable environments caused participants to “exert more effort to maintain their performance” along with lower motivation to do work.

Kim and de Dear authored a 2013 study based on their review of the Center for the Built Environment’s occupant survey databases. They found perceptions of thermal discomfort regardless of office design. Whether enclosed, cubicles, or open plan, occupants expressed dissatisfaction with air temperature in their workplaces.

When occupants report dissatisfaction with air temperature, being too warm is what they find uncomfortable. To summarize a finding in 2011 study by Li, Wargocki, Wyon, and Zhiwei, when subjects felt too warm, their performance decreased, while their heart rates, respiration and carbon dioxide concentrations in their lungs increased. The implication, they wrote, is that feeling thermally warm affects the normal functioning of the human body, with adverse effects on performance and health.

While human beings have the same system for regulating body temperature, that is not to say that these systems function identically in every person. Why this is so, and accommodations for it in workplace design, are topics of Part Two in next week’s issue.

As researcher, writer, and commentator, Stephen Witte reports and advises on trends shaping the future for the A&D community, manufacturers, and distribution channels. He can be reached at switte@stephenwitte.com or through his website, stephenwitte.com.

The author acknowledges and thanks Dr. James Levine, M.D., Ph.D., of the Mayo Clinic for his generous assistance with research for this article.

References

Hedge, A., L. Miller, and J. A. Dorsey. 2013. Occupant comfort and health in green and conventional university buildings. WORK: A Journal of Prevention, Assessment & Rehabilitation: 49, 363-372.

Kim, J. and R. de Dear. 2013. Workspace satisfaction: the privacy-communications trade-off in open-plan offices. JOURNAL OF ENVIRONMENTAL PSYCHOLOGY: doi:10.1016/j.envp.2013.06.007.

Li, Lan, P. Wargocki, D. P. Wyon, and Zhiwei Lian. 2011. Effects of thermal discomfort in an office on perceived air quality, SBS symptoms, physiological responses, and human performance. INDOOR AIR: 21, 376-390.

Li, Lan, Zhiwei Lian, and Li Pan. 2010. The effects of air temperature on office workers’ well-being, workload, and productivity-evaluated subjective ratings APPLIED ERGONOMICS: 42, 29-36.

Škrobonja, Ante and Kontošić, Ivica. 2002. Bernardino Ramazzini’s De Morbis Artificum Diatriba or three hundred years from the beginning of modern occupational medicine. ARCHIVES OF INDUSTRIAL HYGIENE AND TOXICOLOGY: 53, 31-36.