Meet the Fleet: Improved climate control highly anticipated on new trains


Meet the Fleet: Improved climate control highly anticipated on new trains

meet the fleet graphic of new train

By MELISSA JORDAN
BART Senior Web Producer

The Fleet of the Future train cars that begin arriving later this year for testing will have state-of-the-art climate control technology that's not only more comfortable, but more energy-efficient as well. 

Hot cars are a common complaint from riders on BART's oldest-in-the-nation trains. From July 1, 2014 - June 5, 2015, more than 200 riders took the time to call or email customer services with climate complaints, and many more used social media to vent with tweets like "hot as the devil's toenails" (one of the milder ones). 

BART has worked to maintain the aging HVAC -- heating, ventilation and air conditioning -- system on current cars, but major relief will come with the new cars, scheduled to begin passenger service in 2017. (The Board of Directors receives a semi-annual update on the new cars at its meeting this Thursday, June 11, to be webcast at www.bart.gov/board)

"An unbelievable amount of effort has gone into designing these cars to have a large number of improvements for riders," said Ben Holland, manager of vehicle systems engineering.

Holland explained that in the current cars, the HVAC duct system is placed underneath the floor of the cars. You may have felt cool air at your side if you had a seat by the window. 

"It was a very different level of ridership when BART first started," said Mike Healy, retired longtime spokesman who was with BART since its early days. "The ideal was promoted that every rider would have a seat, and there would be this cool, comfortable air conditioning at every seat."  A November 1965 article in the San Francisco Examiner cited BART's plan to "Pamper the Passenger," with the pledge that "Transit passengers will ride in great comfort, with room, light and air conditioning." 

Today, as Healy noted, ridership is bursting at the seams with an average of more than 420,000 trips per day. Standees don't get much of that precious cool air, and even less personal space than riders with seats. 

BETTER AIR FLOW, MORE EFFICIENT

In contrast, the HVAC system on the new train cars will be housed under the car, but the fresh air will be distributed from the ceiling of the cars, providing better air flow throughout the space overall and bringing relief to standees with vents at the top of the car. The heating and cooling system on the new trains will be more energy-efficient, as well. 

The new cars will be equipped with an energy saving mode, during which time doors will open at stations only when a passenger is standing in front of them. By opening doors only when necessary, the energy saving mode will help reduce the amount of lost heat or A/C from the cars. The doors will have redundant sensors to detect persons wishing to enter or exit the train.

WHITE ROOF DEFLECTS LIGHT

In addition to an aluminum exterior, which reflects light to help keep cars cool, the new cars also will be equipped with a white roof to further deflect heat and light away from the interior of the train. The white roof will help lessen the load on the interior cooling system, keeping passengers more comfortable and decreasing energy consumption. Finally, when all the new trains get here as they're rolled out over time, there will be greater capacity to the system -- cutting down on the body heat generated in crowded cars. 

BART gets some, but many fewer complaints about train cars that are too cold  than about those that are too hot, possibly because savvy travelers know about  the roller-coaster ride of temperatures in the Bay Area.

THE LAND OF MICROCLIMATES

graphic showing temperature differences
 

A factor contributing to the challenges of comfortable air on BART is the Bay Area's notorious microclimates.

"It's not unusual to have a 40-degree temperature difference in 40 miles," said Jan Null, lecturer and researcher at San Jose State University in meteorology and climate science. "There are very few places in the United States, if not the world. with such a differential in such a relatively short space," said Null, also a former lead forecaster with the National Weather Service. (See graphic above of sample possible temperatures in BART service area, from data provided by Null.)

The "natural air conditioning" that comes from the unique geography of the region keeps it relatively mild overall year-round, but with wide ranges among microclimates of different areas. (Often misattributed to Mark Twain, a famous quip from an unknown author is, "The coldest winter I ever spent was a summer in San Francisco.") 

The high-tech sensors of the new trains are designed to keep the inside comfortable for passengers, no matter what's going on outside -- from the sun-drenched hills of Walnut Creek to the pea-soup fog of Daly City.

WHAT YOU CAN DO NOW

Meanwhile, if you're stuck in a hot car before the new trains arrive, here are some things to keep in mind:

* The climate on each train car is individually controlled, so if yours is hot, you can try moving to another car. (An empty car on a hot day is often a clue that the air isn't working well inside that car.) 

* The train operator can't adjust the temperature; however, they can put in a service call for a technician to check it out. Use the phone at the end of each train to speak with the operator and note the number of the car you're on (located above the doors at each end of the car).  If a technician isn't available right away, the problem can be logged for maintenance later. A hot car typically would not take a train out of service -- most riders would rather BART keep a hot train running on time than to delay everyone by taking a train out of service.    

*  BART is required by a California Public Utilities Commission order to maintain a high level of circuitry overload protection. Electronics are subject to damage when they become hot, and the critical functions are propulsion and communications. When potential of overload occurs, such as when it is extremely hot or extremely cold outside, the non-essential functions (such as heat and A/C) automatically shut off to preserve the critical propulsion and communications features.The blower will continue to deliver a "flow" or "vent," but there is no heating or cooling. 

Meet the Fleet is an occasional ongoing series looking in-depth at different aspects of BART's new train cars, which are due to arrive with the first of 10 pilot cars for testing in late 2015. The first cars to carry passengers are expected to begin service in 2016. For more details visit www.bart.gov/cars