It can be seen from a plane flying over the city and even from a trail in the North Hills. And now it’s getting an upgrade.

UPMC is in the process of switching the lighting in the 20-foot-high lettering affixed to the top of the 64-story U.S. Steel Tower — going from neon to LED.

Gloria Kreps, a UPMC spokeswoman, said the change is already underway. The neon, she said, is being replaced “with more energy efficient LED lighting within the same letters.”

UPMC is not making any other changes to the three sets of signs — well-known landmarks that created somewhat of a stir when they were first festooned to Pittsburgh’s tallest skyscraper about a decade ago.

The switch to light-emitting diode technology was approved last year, said Corey Layman, the city’s zoning administrator. The approval came with conditions: the signs had to be a single color with no flashing, animation or motion, as well as comply with the city’s brightness ordinance.

In a letter to the city last August, Todd R. Turner, of UPMC corporate construction, sign planning and design, assured officials that the letters would meet the city’s light intensity standards.

“This project will greatly reduce power consumption, and will also be a significant visual improvement to the illumination of our letters, and therefore the city skyline,” he wrote.

East Liberty-based Kolano Design is doing the sign makeover. President William Kolano said the LED lighting actually will be dimmer than the neon that has been used for years.

“It’s in nobody’s interest to have a sign that’s too bright,” he said.

That has not stopped some from complaining on social media site Reddit about the brightness of the lettering, with one post saying it had been casting shadows into a bedroom at night. The post added, however, that the sign did not seem as bright in recent weeks.

Mr. Kolano said that individual may have been experiencing what is called the “burn.”

That’s when the LED lighting is turned up to its highest level to make sure it is working. It then is dimmed to the proper intensity.

So far, LED has replaced neon on two sides of U.S. Steel Tower. The last to be done is the side facing the former Civic Arena site, Mr. Kolano said.

The decision by UPMC to add its letters to the top of Downtown’s signature skyscraper was born in controversy more than a decade ago.

After first rejecting the lettering in June 2007, the city planning commission reversed itself two weeks later after being told the sign met all of the requirements under the zoning code and that the commission could be on “some very shaky legal ground” in not approving it.

The lettering, at 1,900 square feet, was about half the size allowed under the city’s zoning laws.

At the time, UPMC said the sign would be “a visible indication of Pittsburgh’s re-emergence as a national and international leader. No longer reliant on the steel industry, Pittsburgh’s new renaissance is built on science, medicine and technology.”

The lettering certainly had Pittsburgh talking. After the signs were erected on all three sides of the building, one wag likened it to the Eye of Mordor, a reference to the “Lord of the Rings” fantasy series, so ever present was it on the city skyline.

In a bit of hyperbole, then-city Council President Doug Shields suggested that it could be seen from Chestnut Ridge in the Laurel Highlands.

“It’s brighter, bigger, more dominating in the skyline than any other identification sign,” he said in 2009.

UPMC currently has a lease to occupy about 962,000 square feet of space in the 2.3-million-square-foot U.S. Steel Tower. It has 4,000 employees in the building spread over 28 full floors and two partial ones.

Of course, the health care giant is not the only one to put its name in lights on a Golden Triangle building. Its rival, Highmark, also has its name on its Downtown building.

In fact, there has been an explosion in the number of high-wall signs — those more than 40 feet above the ground — since the opening of PNC Park and Heinz Field in 2001.

In the first eight years since the ballpark opened, the planning commission approved 18 such signs for Downtown and the Strip District, and more have been added since.

Mr. Kolano, whose firm has designed the vast majority of the high-wall signs in Downtown, said about half of them are LED. The first LED one went up in 2010 when BNY Mellon added its name to the skyline.

Those that have come after that are all pretty much LED, he said. The technology is more energy efficient, lasts much longer than neon, and has a much cleaner look, he said.

Changes are being made for practical reasons as well. The biggest one is that many of the neon shops, as Mr. Kolano called them, have closed, making it much more difficult to get replacement parts.

Since neon usually has about a seven-year lifespan, Mr. Kolano expects many of the older Downtown signs to upgrade to the newer technology at some point.

Another problem with neon, he said, is that it is temperature sensitive, making it difficult to regulate throughout the year. It might be too bright in the summer and too dim in the winter.

“The new LED is temperature stable. You won’t get those peaks and valleys in sign brightness,” he said.

Mark Belko: mbelko@post-gazette.com or 412-263-1262.

First Published: January 28, 2019, 10:45 a.m.