At 35,000 acres, Denver International Airport (DIA) is the largest airport site in North America, and the second largest in the world. More than 53 million passengers travel through the airport annually. With volume like that, the airport’s HVAC filtration system is extremely important.
By 2009, the airport’s system had become an inefficient patchwork of solutions that required frequent attention from the maintenance department. On top of needing to change its more than 3,000 filters approximately eight times per year (up to 24,000 filters a year), the existing system also demanded a lot of energy to run.
DIA put out a call for a standardized HVAC filtration solution that could help it reduce its labor costs as well as the waste stream involved in so many filter changes. The facility also hoped to reduce the energy consumption of its HVAC system, while at the same time improving or maintaining the particle capture efficiency of its filters.
Based on the airport’s requests, experts from 3M Purification proposed a solution that could meet each of the facility’s needs by replacing more than three-fourths of the airport’s total filtration system with a standardized MERV 14 high-efficiency 3M filtration system. According to 3M, the new standardized filtration system resulted in a decrease to the overall pressure drop by approximately 50%, in addition to a reduction of filter changes by approximately 75% per year.
The company also found that the solution standardized DIA’s filtration system in every concourse and achieved the desired air quality, while also substantially reducing energy consumption, labor, and waste disposal.
While many areas in DIA had been using a two-stage filtration system, 3M Purification suggested a single-stage system that would standardize applications to MERV 14 particle capture efficiency and reduce energy consumption.
3M Purification said it was willing to prove the effectiveness of its system in a series of on-site trials that lasted approximately three and a half years, with each trial building on the results of the one before. Performance of the filters and air handlers was measured using both handheld instruments and data-logging equipment to capture information on pressure drop, velocity, and particle counts. The final trial saw the installation of sensors that gave the team readouts every 15 minutes for six different air handlers in the concourses. Once complete, this trial yielded more than 200,000 data points — adding up to a clear demonstration that validated the system’s total cost of ownership and performance improvements.
The results showed that 3M’s solution performed well within DIA’s specifications for pressure drops, which will result in significant energy savings for the facility. In addition, the project’s goal of reducing filter changes to every six months was exceeded. Furthermore, the higher particle capture and unique integrated gasketing of 3M Purification’s filters will help keep the HVAC coils cleaner, thus providing improved thermal transfer efficiency over time, which also has the potential to reduce energy costs.
“With this solution, DIA has largely standardized its applications,” said Joe Dardis, regional sales manager for 3M Purification. “They’ve gone from using a multitude of different types of filters changed out frequently to a simpler solution using 3M filtration. The standardization has led to the maintenance staff managing filtration change outs based on performance and not a predetermined schedule. This gives them the flexibility to more efficiently manage the operational and energy costs associated with filtration.”
The airport’s achievement was recently recognized by the National Air Filtration Association, which included the project in its 2013 Clean Air Awards. These awards recognize the use of high-efficiency filtration products and good maintenance practices, and are presented to organizations and facilities that make outstanding efforts in maintaining a clean and healthy indoor work environment, while reducing overall operating costs.
“Denver International Airport is one of the most environmentally friendly airports in the world, and this project helps further decrease the airport’s environmental footprint,” said Denver International Airport’s deputy manager of aviation for airport infrastructure management, Dave LaPorte. “This new air filtration system not only improved our indoor air quality, it’s also more efficient, uses less energy, produces less solid waste, and reduces the labor costs associated with maintaining our heating and air system.”