Facility Retrofit: Heat And Glare Control

By Anne Cosgrove
From the May/June 2015 issue

What were the motivating factors and goals for this project?
The goal of the retrofit was to improve interior comfort by reducing glare and energy use, and give a more uniform look to the building’s exterior.

We were looking into ways to improve the comfort and climate of the hotel. The hotel, as well as the building it is located in, was working toward LEED certification. We were undergoing a $20 million redesign that included extensive ecological programs. These efforts included installing window film (to reduce solar loading and subsequently energy costs).

The building’s large 4,200 square foot lobby atrium area was completed in 2009 with exterior solar control window film. Next, the work was done floor by floor for several years as permitted by overall refurbishing. The window film program is ongoing as the building is updated on all sides, with portions of the north facing side underway as permitted.

Please give an overview of the facility, and describe the areas involved in this project.
The Holiday Inn Chicago Mart Plaza River North is located atop the landmark, 24 story, mixed use River North Point [also known as the Apparel Center]. The 521 room hotel sits near the confluence of the east, north, and south branches of the Chicago River. Opened in 1977, this 2.5 million square foot riverfront complex was designed by Skidmore, Owings & Merrill. The hotel itself is 10 stories, beginning at the 15th floor of River North Point and rising to the top of the building.

The hotel’s 521 guest rooms and suites features contemporary furnishings, with many providing premium views of the Chicago skyline.
The hotel’s 521 guest rooms and suites features contemporary furnishings, with many providing premium views of the Chicago skyline. (Photo: Holiday Inn Chicago Mart Plaza River North.)

The hotel offers omnidirectional views of the city of Chicago with half of our guest rooms having westerly and southern exposure with no overshadowing from nearby office buildings. The hotel also includes a large skylit glass atrium and lobby that receives significant solar exposure. We have 25,000 square feet of flexible meeting space, which includes floor to ceiling windows in the 15th floor meeting rooms.

What problems were you encountering before the window film retrofit? How were these impacting operations?
Direct ultraviolet exposure from the skylit atrium caused our front desk employees to experience glare in the morning and until the sun arched across the horizon. This direct exposure made it difficult for them to perform their tasks. Additionally, solar loading created excessive heat buildup on the upper floors of the atrium, thus creating uncomfortable temperatures year-round. During the winter months, air conditioning had to be run mid-morning to late afternoon to mitigate the elevated space temperature.

To address this, we installed window treatments on the lobby level, but this blocked the magnificent views of the river and skyline.

Meanwhile, guest rooms facing south and west had solar loading and glare issues. Window treatments [that might combat these issues] were being left in varying positions, causing a checkerboard effect when viewed from the street, thus reducing curb appeal.

How did you research the options? And how did you arrive at the final decision?
We contacted John Parker, president of the International Window Film Association (IWFA) and partner at National Security & Window Filming, based in Oak Forest, IL, to meet to evaluate what application of window film would be best for the hotel. We researched options using the dealer locator on the IWFA website. Once we met, we determined National Security & Window Filming had the experience needed for the job.

The atrium lobby provides natural daylight into the hotel’s central space.
The atrium lobby provides natural daylight into the hotel’s central space. (Photo: Holiday Inn Chicago Mart Plaza River North).

John and his team came up with a solution and presented it to me. The plan was to install exterior solar control film designed to the skylights in the 4,200 square foot atrium. As noted earlier, due to exposure to the elements in this space, solar heat and glare was impacting the lobby.

Another type of film was applied in the guest rooms. Older existing window film was removed and new, advanced film was installed. The product chosen provides protection from solar load and sun damage without darkening the city views from those rooms. The film offers heat rejection—up to 80%, while allowing 50% of visible light to enter. There is also glare reduction and 99% of UV rays blocked, with a low reflectivity.

We agreed on the plan, and John’s team began the installation.

What have the results been?
I tracked the window film installation progress by measuring various areas and substrates to determine temperature gradients and noted as much as a 20° delta in surface temperatures. Reducing solar load and glare were achieved. Overall, we have reduced the temperature in the lobby area significantly since the installation was completed in that area. Now on hot summer days, the HVAC system can easily handle the cooling load while maintaining electrical consumption; we have extra cooling capacity.

Another benefit was reducing ultraviolet degradation of our wood flooring, carpeting, fabrics, and window treatments. And it has also reduced the exterior checkerboard appearance from window treatments being set at varying levels.

With the window film project and other renovations completed, the Holiday Inn Chicago Mart Plaza achieved LEED Gold-Operations & Maintenance: Existing Buildings certification from the U.S. Green Building Council in 2009.

We are now considering installing window film on the north side of the building. This will not only deliver a uniform look around the entire hotel, it will capture additional energy savings by blocking the sun’s ultraviolet rays.

Visit the Holiday Inn Chicago Mart Plaza River North website. For more information from the International Window Film Association, visit www.iwfa.com.