Daniel Marsula, Post-GazetteClick illustration for larger image. Learn more Graphic: What a PEM is and a comparison of air systems (11.3 MB download) Listen In: Hear excerpts from Vivian Loftness's conversation with PG reporter Mark Roth: The problems that come with blowing cold air out of ceiling diffusers Workers can lose their voices after new carpeting has been installed. The car industry long ago figured out how to provide individualized AC.

Denny Earhart and Lawanda Foyle are a classic example of how hard it is to get conditions in the workplace just right for everybody.

Mr. Earhart, a PNC operations manager, comfortably wears short-sleeved shirts every day, year-round. Ms. Foyle, a PNC records custodian, always keeps a sweater handy.

And they have the advantage of working in one of the most environmentally advanced buildings in the nation -- the PNC Firstside Center at First Avenue and Grant Street, Downtown.

Employees in hundreds of other buildings in the region, and millions in the United States, aren't nearly as lucky.

Not only are they unable to experience a consistent temperature that makes everyone happy, but they are also breathing far too little fresh air, are exposed to too many contaminants and are often blocked from getting natural light.

And if anyone thinks those factors don't have a big impact on the people in offices, hospitals and schools, they should consult the work of Ole Fanger.

Dr. Fanger, a pioneering Danish researcher who died three weeks ago of an aortic aneurysm, said in an interview a week before his death that he had done scores of studies that proved poor temperature control and ventilation have an adverse effect on people's performance.

In one recent experiment, Dr. Fanger's team had several women work in a simulated office in which air was blowing across hidden panels of "a 20-year-old, tufted boucle carpet collected from an office building with a history of poor air quality and occupant complaints."

The women exposed to the carpet pollution had more headaches, were less efficient and did worse on typing tests than women who worked in the office when the carpeting was removed, the study said.

In another experiment, Dr. Fanger's group set the temperature in a school classroom to 78 degrees and had the children take math and language tests. They then lowered the temperature to an optimal 68 degrees and had them repeat the tests. The pupils showed a 15 percent improvement at the cooler temperature, he said.

Add to these results the fact that everyone perceives temperature and air quality differently, and it gives a sense of how challenging it can be to create an ideal workplace atmosphere.

Clark Blatteis, a thermophysiologist at the University of Tennessee College of Medicine, said individual temperature perception can be affected by a person's body size and weight, level of activity, what time of day it is, the amount of clothing worn and sitting near a window.

Many employees subscribe to the belief that, like PNC's Mr. Earhart and Ms. Foyle, women tend to be colder than men in the same space.

Dr. Fanger said his studies had not shown gender differences in temperature perception, but Dr. Philip Mackowiak, a physician at the Veterans Affairs Medical Center in Baltimore, said his research on 148 men and women had shown that the women had a slightly higher average body temperature than the men. That could make them feel colder in the same environment, just as a person with a fever gets the chills, he said.

In any case, Dr. Fanger said, his studies have shown that even when buildings are designed and operated to meet national air conditioning standards in the United States and Europe, about 20 percent of the employees will be dissatisfied, with half saying it's too cold and half saying it's too warm.

That is why the holy grail of HVAC -- heating, ventilating and air conditioning -- should be to provide temperature and ventilation control to each employee, he said.

That's exactly what's being done at Carnegie Mellon University's Robert L. Preger Intelligent Workplace, a glass-enclosed experimental office perched atop the Margaret Morrison building on the school campus.

There are three basic techniques being used at the Intelligent Workplace that differ from the typical systems in office buildings, said two of the architecture professors who work there, Vivian Loftness and Stephen Lee.

First, they said, the structure's breathing air is separated from its cooling and heating systems.

The ventilation air comes through circular diffusers at each work station, and employees can easily adjust the air flow by twisting the top of the diffuser, or opening their windows if they need extra air.

Heating and cooling are handled by a variety of radiant water systems in the ceiling or walls.

The second innovation is that the diffusers are in the floor.

After years of being taught that cold air sinks and warm air rises, it may seem counterintuitive for cool air to come up through the floor.

But that in fact is what works best, said Professor Loftness. "The best place to introduce the air is at a point where it's closest to the human body. As it warms up slightly from body heat, it rises up to provide fresh breathing air to people's noses," she said. "If you introduce it in the ceiling and blow it down," the system "has to push it to get it to your shoulders."

"Also," added Professor Lee, in a ceiling-based system, "a lot of the air hugs the ceiling and dirt collects there, so whenever the system is turned on, it blows dirt down toward workers' lungs."

The PNC Firstside Center, Alcoa's headquarters building on the North Shore and the Soffer Organization's Penn Center West project on the Parkway West also have ventilation air that rises up through floor vents.

One of PNC Firstside's architects, Patrick Branch of Astorino, said that makes a tremendous difference in how much fresh air circulates to workers.

The typical American office building recirculates 80 percent to 90 percent of its air.

Or, as Professor Loftness put it, "nine-tenths of the air [in a building] is your own cruddy air going back to the central system, being filtered -- hopefully well filtered, but not always -- and then mixed with a little outside air."

At Firstside, those percentages are reversed -- about 80 percent of the air employees breathe is fresh air pulled in from the outdoors, Mr. Branch said.

The upward flow of air also helps remove contaminants -- both the carbon dioxide people exhale and the toxins in office materials -- by wafting them through the ceiling and back outdoors, he said.

The third innovation that Carnegie Mellon's Intelligent Workplace uses is PEMs -- personal environmental modules developed by Johnson Controls.

The PEMs are connected to the ventilation system and mounted on each employee's desk. They have controls that let each worker adjust the temperature in the work space by mixing warmer room air and cooler ventilation air or by turning on a radiant heat panel beneath the desk.

The PEMs even have one control that lets people create white noise to screen out distracting sounds.

Professor Loftness said she didn't know of any corporate offices in Pittsburgh with PEMs, but she noted that a study done at a West Bend Mutual Insurance Co. building in Wisconsin showed that the modules increased worker productivity by more than 2 percent, enough to quickly pay for their cost.

There is one other advantage to the newer ventilation systems -- they can save significant energy.

When air diffusers are in the ceiling. Professor Loftness said, the air has to be blown in at a chilly 55 degrees to achieve average temperatures in the low-to-mid-70s for the occupants below.

When the air comes up through the floor, it can enter at 65 degrees through a greater number of diffusers and achieve the same result, Mr. Branch said.

Designing buildings that cool and heat with less energy will become increasingly important as more and more of the world's population moves into cities, said Volker Hartkopf, director of the Center for Building Performance and Diagnostics at Carnegie Mellon.

In the United States today, Dr. Hartkopf said, 70 percent of all electrical power goes into heating and air conditioning buildings.

In general, Professor Loftness added, Americans have a long way to go in improving their air-conditioning and ventilating systems, especially to catch up with Western Europe and Scandinavia. In many of those nations, she said, ventilation air already is separated from heating and air conditioning.

Why the difference?

"In Europe," she said, "workers have rights. They actually have the right to refuse to move into a building. And by now, they've felt how good thermal comfort control is, so they know to ask for it."