"Dummy" Thermostats Cool Down Tempers, Not Temperatures

April 11, 2003

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The secret's out—many thermostats just trick building occupants into feeling more comfortable and in control. Here's why they're so effective.

On Jan. 15, The Wall Street Journal revealed that the HVAC industry has an unconventional way of attending to the comfort needs of building occupants—using thermostats that aren't configured to have an effect on the HVAC system.

"Looking for an office thermostat that actually works? Good luck and Godspeed," wrote Jared Sandberg. "You may never find it…If you do spy a thermostat, it's probably locked, or encased behind shatterproof glass."

"Even worse, HVAC experts acknowledge what millions of office workers have suspected all along: A lot of office thermostats are completely fake—meant to dupe you into thinking you've altered the office weather conditions."

Some may say "dupe," but the purpose of installing nonfunctional thermostats is to keep building occupants feeling comfortable and in control, say many engineers, contractors and wholesalers in the HVACR industry. Still, some manufacturers do not approve of their intentional use—or non-use for that matter.

And even though these thermostats do not actually provide a direct interface to the mechanical system, by giving the illusion that they do, they act as a placebo in many cases.

"We had an employee that always complained of being hot," recalls Greg Perakes, an HVACR instructor in Tennessee. "Our solution was to install a pneumatic thermostat. We ran the main air line to it inside of an enclosed I-beam. Then we just attached a short piece of tubing to the branch outlet (terminating inside the I-beam without being attached to any valves, etc.)."

The worker "could adjust her own temperature whenever she felt the need," Perakes says, "thus enabling her to work more and complain less. When she heard the hissing air coming from inside the I-beam, she felt in control. We never heard another word about the situation from her again. Case solved."

This approach seems to be taken by many others in the industry. The Air-Conditioning, Heating & Refrigeration News conducted an informal survey on its web site, asking "Have you installed 'dummy thermostats'?" Out of 70 total responses, 51 said yes, they had; only 19 said no.

To explain the effectiveness of nonfunctional thermostats, former News editor Tom Mahoney points to the words of esteemed HVACR engineer Joe Olivieri. He "always said that 'thermal comfort is 90% mental and 10% physical,'" recalls Mahoney.

Also, these thermostats' placebo effect may be partly explained by our own physical ability to adjust to the environment. This ability or tendency is called "homeostasis" and according to Webster's New World College Dictionary, organisms achieve homeostasis through "organ systems that automatically compensate for environmental changes."

And not only do our bodies make adjustments such as producing sweat, inducing shivering, and widening or constricting blood vessels to radiate more or less heat, we also have more sophisticated methods of maintaining our internal temperature, says Mary-Louise Kean, a professor of cognitive sciences with the University of California-Levine School of Social Sciences.

"There are other options available which add a layer of complexity to the story of temperature control," she says. "If a person is cold, he or she has the option of putting on a sweater, seeking shelter, or increasing indoor temperature of his or her home. Thus, not only does the biological system contribute to a relatively constant internal temperature, but humans (and some other animals) can make use of their cognitive abilities to contribute to keeping the homeostatic balance."

This means that if a person feels too hot, he or she could react by sweating, fiddling with a nonfunctional thermostat, taking off a layer of clothing and drinking something cold. While that person could credit his or her renewed sense of comfort to the thermostat adjustment, it is really due to homeostasis.

Another important function of placebo thermostats is giving building occupants a sense of control. According to Dan Int-Hout, chief engineer for Dallas-based manufacturer Krueger and former chair of the ASHRAE Standard 55 (Thermal Environmental Conditions for Human Occupancy) committee, such thermostats sometimes work for occupants who may not be too hot or cold "but want to have a degree of control."

Many respondents of The News' survey echoed this sentiment, indicating that nonfunctional thermostats may be in large part for occupants who need to have a say over their environment. For example, Vaughn Langless of Rochester, NY wrote that after installing two rooftop air-handling units with air conditioning and natural gas heat exchangers in an office space, his staff was bombarded with requests to raise or lower the space temperatures.

"Even though we were sure our system was working as it should and maintaining space temps to within one degree to two degrees, we could never completely satisfy the occupants of the space," he wrote. "We mounted a 'dummy stat' (short for 'dummy thermostat') adjacent to the 'controlling stat' and gave the floor manager the key to the stat—now the occupants could 'control' their space as they desired with the permission of their manager."

"The dummy stat did nothing except to give the occupants the impression that they had control of the HVAC system and the psychological effect of having control of their work environment," continued Langless. "Our service calls disappeared, and to my knowledge, that system is still set up and working as it has since 1987."

In addition, nonfunctional thermostats help protect equipment because functional thermostats are often subjected to excessively frequent adjustments during "thermostat wars" and even abuse, including burning with cigarette lighters. In fact, installing dummy thermostats can sometimes be more effective than mounting a thermostat guard. This is because in public areas, a thermostat guard "by its very presence makes thermostats vulnerable to tampering," says John Sartain, market manager of thermostats at White-Rodgers, part of Emerson Climate Technologies.

"Most people can identify a thermostat or a thermostat enclosed in an opaque or metal guard," continues Sartain. "So a secondary goal in some applications is to keep the public and others from 'playing' with the setting and possibly causing discomfort or equipment damage."

While the public has access to nonfunctioning thermostats, "the thermostat itself can be positioned in a more secure location, like the manager's office," he says. Indeed, remote sensors are now available to allow the manager or any other authorized person to set the temperature in a certain area, such as the dining room, from a remote location.

But before going ahead and installing placebo thermostats, keep a few things in mind. For starters, the facility decision-maker should be informed right away if a contractor thinks that using a nonfunctional thermostat is a sound idea. "The owner of the building needs to be made aware of it," says Sartain.

Also, such thermostats should not be considered as the only solution. "If you have the opportunity to give the public control over their environment, you should," says Dan Int-Hout. "Locked thermostats in a nonpublic building are demoralizing—it sends the message that management doesn't trust the employees." Indeed, research from Johnson Controls indicates that "investing in the indoor environment can be justified on the basis of productivity improvements alone."

In addition, remember that installing nonfunctional thermostats won't satisfy the needs of occupants if building conditions are truly uncomfortable. For example, service contractors should check to see if air stratification is behind complaints. When air diffusers don't work properly, colder air stays at the foot/ankle level. In such cases, the HVAC system should be repaired, Int-Hout says.

The bottom line—make sure your equipment is functioning. As poll respondent Doug Huberty from St. Paul put it, "If you fix the problems causing the too-hot, too-cold complaints, the staff forgets there is a thermostat on the wall."

Source: Placebo Stats
Barb Checket-Hanks
The Air-Conditioning, Heating & Refrigeration News, Mar. 27, 2003
http://www.achrnews.com/CDA/ArticleInformation/coverstory/BNPCoverStoryItem/0,6152,95170,00.html

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