December 19, 2018

PSTA pilots connected HVAC


For the Pinellas Suncoast Transit Authority (PSTA), onboard energy consumption on buses is of keen concern.

PSTA serves Pinellas County, including the coastal communities of St. Petersburg and Clearwater, with a fleet of 210 diesel and hybrid-electric buses. Furthermore, the agency recently received its first two all-electric vehicles. To provide the best maintenance and extend the driving range of its diverse fleet in the hot Florida climate, PSTA must pay special attention to the energy consumption of bus HVAC systems, said Joseph Cheney Jr., deputy director of fleet operations, “A big part of what we do includes tracking automated data,” Cheney said.

“We are always looking to increase the reliability of our fleet. Furthermore, analyzing maintenance data allows us to reduce downtime and identify opportunities for better energy efficiency — especially in the HVAC system, which accounts for more onboard energy consumption than any system on the electric buses as it also did on the conventional engine/drive system.”

With the rising cost of fuel inspiring a push to reduce energy costs in other areas, Cheney said that a conversation about data last year with Thermo King resulted in a perfect opportunity for PSTA.

Thermo King, based in Minneapolis, Minnesota, is an industry leader in transit HVAC, as well as in HVAC and refrigeration in other road, rail and marine industries. The company, which has a longstanding connected telematics solution for trailer refrigeration, informed Cheney that they were beginning user trials of a similar solution specialized for transit bus operations.

“We have a very good relationship with Thermo King dating back years, and they provide 100 percent of the HVAC systems at PSTA,” Cheney said. “When I heard about a pilot program for transit bus HVAC systems, I told our Thermo King sales representative Jeff Frachiseur that PSTA wanted to be among the first agencies to sign up.”


PSTA begins the trial

For the next three months after that initial conversation, Thermo King took existing intelligence used for the trailer systems along with survey data from transit agencies and custom configured a solution for transit buses. Cheney was informed that PSTA could begin undertaking a pilot program with the HVAC telematics system (at no cost to the agency).

“We tailored this solution for bus HVAC based on input from our customer operators,” said Steve D. Johnson, product marketing manager of bus HVAC at Thermo King. “Our telematics team created the model, so the next natural step was testing it in real-world operations.”

Thermo King made the necessary installations, implementing routers and cabling on 15 PSTA vehicles. Cheney said that training on the system was intuitive, requiring users to learn how to use a web-based portal to access the telematics system. Cheney and Rocky Macaluso, PSTA superintendent of training, learned the system and trained the rest of the staff.

Connected HVAC

The system allows PSTA technicians to see, in an easy-to-use graphical layout, the GPS locations, routes and system temperatures.

“This system lets us look at what the vehicle is doing in real time while it’s in service,” Cheney said. “We can see what HVAC mode the vehicle is running, as well as potential problems and opportunities related to energy consumption.”

Cheney said that, by analyzing the route profile of a given bus, PSTA can easily identify aberrations in performance and thereby mitigate errors before they cause serious problems.

In one example, he said PSTA recently pulled a bus from service after the vehicle showed temperatures abnormal for its route. After a diagnostics test on the bus, technicians were able to fix the problem in around 15 minutes.

“Being able to pull up that information from my office saved a road call, and it saved us from a potential larger failure,” Cheney said.

Since then, Cheney has been able to proactively diagnose issues on five different occasions.

The system reveals several critical data and potential events to Cheney and his team at PSTA, including evaporator coil freezes, air duct temperatures, failure logs, historical data and temperature variations.

“Another bus was experiencing HVAC issues which we then identified by searching through the previous day’s system history,” Cheney said. “We found a failed solenoid on one of the compressor’s loading valves which only fails when it gets too hot. Without the telematics system, we would have been chasing our own tail for a while to identify that issue.”

“Road calls involve taking a bus off the road mid-route,” he said. “Sometimes it even involves offloading passengers. It interrupts operations, decreases asset utilization and increases operating costs.”


Data yields benefits

Johnson said that Thermo King is gaining invaluable data in its pilot program with PSTA. 

“This the perfect fleet for the trial,” he said. “Although the sample size is only 15 buses, we are actually monitoring four different fleets, 2010, 2013 and 2015 hybrids using engine driven HVAC, and 2016 hybrids with all-electric HVAC.”

“We’re collecting a lot of data and beginning to analyze it, which is resulting in less road calls and more information about how PSTA’s buses are running and how the HVAC system is being used,” Johnson added. “I believe this system will contribute significantly to energy management and range of transit buses, especially as more electric vehicles are introduced to the industry.”

Though PSTA has only been using the telematics system for a short time, Cheney said the agency has already been impressed with the several averted failures and the overall lower cost of repairs. He has also provided some valuable feedback to Thermo King about improving the system.

“While we’re still learning the intricacies of the system, my initial reaction is that it’s great,” Cheney said. “We love data at PSTA, and this provides more data and information than has ever been available.”