Window Retrofit Achieves High Efficiencies

In 2012, Kevon Office Center, a 40-year-old office building in Pennsauken, N.J., received an Energy Star rating of 90, placing it among the top 10 percent for energy efficiency in buildings of its type across the country. Nevertheless, when it came to utility bills, the owners, Philadelphia-based Kaiserman Company Inc., knew they were still throwing money out of the building’s old, single-pane windows. They decided to make an investment in the Renovate by Berkowitz LLC (RbB) window-retrofitting system.

High Reward without the High Cost
Like many commercial buildings built in the past 30 to 60 years, the 100,000-square-foot Kevon Office Center was constructed without the energy-efficient insulating window technologies available today. The building’s clear single-pane windows, originally installed in 1971, lacked a low-e coating and an insulating barrier and, consequently, were notorious for letting solar heat in during summer and letting furnace heat escape during the winter.

The Environmental Protection Agency (EPA) estimates that inefficient windows like those in Kevon Office Center account for as much as 25 percent of a typical building’s heating load in cold climates and 50 percent of the cooling load in warm climates. Knowing the mix of weather conditions in the greater Philadelphia area, Kaiserman Company began to investigate window retrofit solutions that could have a big impact on reducing year-round energy costs.

“We researched a few options and considered a number of variables, including climate, glass surface area, building orientation, past experience and cost,” said Carolyn Pfeiffer, commercial property manager for Kaiserman Company. “We had used window film in the past, but found that it deteriorates over time. It is really only effective in warm weather and it also enables condensation to build up, so we knew window film was not going to help us reach our goals.”

The company also considered traditional window replacement, which can yield significant improvements in energy efficiency, but comes at a high cost in terms of price and tenant disruption. “Money is always one of the top considerations in any project,” Pfeiffer noted. “For this project, we were looking at updating 651 windows with 19,000 square feet of glass surface area. The cost of doing a full window replacement was prohibitive, so we decided to take another look at the RbB system, which produced great results for us the first time we used it.”

One year earlier, Kaiserman Company had updated another 40-year-old high-rise in downtown Philadelphia with the RbB system, which had just been introduced to the market. Because of the significant energy savings they achieved at that location — as well as the positive feedback they got from tenants — the company decided to install the RbB system at Kevon Office Center.

“When you’re upgrading windows with the RbB system, you’re adding a factory-made insulating glass unit (IGU) to the existing single-pane glass, so there’s relatively no construction waste,” Pfeiffer explained. “The building remains enclosed and the project moves fast, eliminating the time and cost of temporarily relocating tenants. And with a cost estimate that came in at about half of a traditional window replacement, it was an easy decision to specify the RbB system. It was a win-win-win.”

Kaiserman Company selected the RbB Platinum Plus II system for the east-, west-, and north-facing offices of the two-building, four-story Kevon Office Center, and the Platinum Plus II XL system for the south elevations, which are exposed to more solar heat gain throughout the day.

“The RbB system works by adding two lites of high-performance, low-e glass to the existing interior window surface, creating a permanently sealed, no-maintenance, triple-glazed IGU,” said Arthur Berkowitz, president of J.E. Berkowitz, the company that developed the window retrofitting system. “The new IGUs offer a solar heat gain coefficient (SHGC) of as low as 0.27, a winter U-Value of 0.15, and an R-value of 6.67. The system also rates 37 on the Sound Transmittance Class scale, which helps minimize the outside noise from the nearby highway.”

A Hub of Information
Kevon Office Center is one of three projects being monitored by the U.S. Department of Energy’s Energy Efficient Buildings (EEB) Hub. Headquartered in Philadelphia, the EEB Hub was established to accelerate the adoption of Advanced Energy Retrofits for commercial buildings by making use of new but proven technologies, systems and processes. The EEB Hub aims to develop the means and methods to reduce energy use in commercial buildings by 20 percent by the end of this decade.

Hank Foley, executive director of the EEB Hub, said, “It is clear that the glazing retrofit at Kevon Office Center will reduce energy consumption. We are measuring the amount so we can better understand the value proposition for this type of window retrofit.”

Berkowitz expects the RbB system to have a significant impact on the building’s utility bills. “Simulations using energy-modeling software showed that the RbB system may enable Kevon Office Center to lower annual energy costs by up to 26 percent,” he explained. “That’s pretty impressive for a building that already ranks among the most energy-efficient of its kind, and presumably doesn’t have much more fat to trim, so to speak.”

Kevon Office Center also is part of a $1.6 million DOE-funded project with Quanta Technologies and the NAHB Research Center. Thomas Culp of Birch Point Consulting, who works with the Glass Association of North America, is managing the study to measure indoor thermal comfort using tools such as mean radiant temperature tracking and infrared imaging.

“We have anecdotal reports of improved indoor comfort since the installation of the RbB system at Kevon Office Center,” Culp said. “When our study is complete, we’ll be able to quantify this effect.”

In addition to updating Kevon Office Center with the RbB window retrofitting system, Kaiserman Company installed solar panels on the complex’s roof, applied cool roof coatings, and retrofitted all lighting with high-efficiency fixtures.

“The building received a 90 on the EPA’s energy performance scale prior to these renovations,” said Homer Robinson, president and CEO of Kaiserman Company. “While we are proud of this achievement, we actively track the performance of all our commercial properties and we saw room for improvement. The installation of the RbB system, along with the other updates we’ve made, will certainly lower our energy costs, improve the comfort level for our tenants, and help the building earn a higher rating,” he added.

Kaiserman Company plans to resubmit Kevon Office Center for Energy Star certification in late 2013.

Darrell Cherry is the business development manager at Renovate by Berkowitz.