Year-round Maintenance is the Key to Comfort

It may seem like ancient history but there was a time when, unlike today, traveling on a bus or subway train that was adequately cooled in summer or heated in winter was a luxury. Neither of the fleets were fully air conditioned and spotty maintenance practices made it less likely of customers were going to ride comfortably during the dog days of summer.

But three decades and four MTA Capital Programs later, we have vastly altered the comfort dynamics of MTA New York City Transit’s buses and subway trains. Riders now benefit from vehicle fleets that are 100% air conditioned, while improved maintenance practices ensure that the Heating, Ventilation and Air Conditioning (HVAC) systems are calibrated properly and working as designed.

Capital Program funding has made a huge difference, as it was the funding source for new and overhauled subway cars. Of the rebuilt railcars, nearly 1,400 were originally manufactured without air conditioning. Transit buses were designed with newly engineered systems which helped increase efficiency and reliability while improved maintenance practices keep the systems operating at peak performance.

“New York can certainly be a City of extremes and that especially goes for the weather. The range of heat and cold are enormously taxing, calling for HVAC systems that are both well designed and well maintained,” said NYC Transit President Carmen Bianco. “We work year round to make certain that the climate-control systems on our subway trains and buses provide the level of comfort our customers expect and deserve.”

Before buses were cool

Transit bus air conditioning has gone through two distinct phases and is currently in a third. During the initial stage, customers viewed a chilled bus interior as a novelty. A little later on, it attained luxury status meaning you were fortunate to board a bus where the A/C actually worked. Today, however, putting a bus on the street with a well-functioning climate-control system is a necessity that NYC Transit’s bus customers have come to expect.

“We look at our operation as “Buses as a Business,” and as with any business, you must give the customer what they are paying for. A well-functioning HVAC system is very much a part of what our customers expect,” said Darryl Irick, President, MTA Bus/Senior Vice President New York City Transit Department of Buses.

The HVAC system on board buses is inspected twice a year to help meet the bus HVAC performance and reliability expectations. A comprehensive preventative maintenance inspection is performed annually, followed six months later by a supplementary running” inspection. Air conditioning compressor belt tension and refrigerant state of charge are checked during both procedures.

Return air filters are changed out every thirty days during the summer and every 60 days throughout the rest of the year. All scheduled HVAC maintenance is performed between the months of September and June, ensuring that the systems are in top operating condition at the beginning of the A/C season.

This pro-active system tuning allows A/C-qualified personnel to quickly resolve any problems that may occur during the peak season. Periodically, audits of bus HVAC system operation are conducted. HVAC “target” decals are installed on every bus to ensure these audits are conducted accurately and consistently.

Fresh engineering to keep customers cool and the environment green

New buses are delivered with 407C and 134A refrigerant, which is more environmentally friendly than older R-22. HVAC system manufacturers have redesigned their entire systems for optimum performance. A/C units are now mounted on the roof of the bus instead of the rear. This results in less dirt accumulation, and makes it easier for maintenance personnel to replace filters.

Taking advantage of new technology, the HVAC systems on new buses have monitoring capabilities that can detect problems and send error messages directly to depots, which can speed up diagnostic and repair time. Other innovations designed to improve efficiency, fuel economy, and reliability are being evaluated, including an all-electric A/C system.

Cooling beneath the streets

Controlling the climate onboard NYC Transit subway trains was no less challenging than buses and the effort began in July, 1967 when a ten-car train of R38 model subway cars was placed into service along the F Subway Line. Subsequent orders of lettered-line cars were delivered with A/C, but the comfort feature remained elusive for riders on the numbered lines. In 1975 however, a pair of ten-car trains was placed in service on the IRT. This effort capped more than two decades of work to develop a unit compact enough to fit in the car body of the smaller IRT cars and powerful enough to keep a full rush hour passenger load comfortable.

Reliability is a major concern with any HVAC system and NYC Transit subway cars are no exception. Aside from regular routine inspection and maintenance, the systems undergo an extensive scheduled maintenance system overhaul every 14 years. This effort includes a detailed tear down of the subcomponents, replacement of long-term wear items, coolant and pressure testing, cleaning and lubrication of all moving parts and complete functional performance testing.

NYC Transit makes every effort to maintain customer comfort. When a fault with the system is reported, the train is removed from service and the problem repaired. On the newer car classes, however, a failed unit does not translate into a hot car. Transit’s “new technology” cars are designed with dual roof mounted units. This is a redundant design system which allows minimum cooling in the event one of the overhead units fail while the train is in service. Fast and efficient maintenance The units are also designed to be removed from the car as a single unit and replaced by another while under repair. “This design means that there is a minimum of downtime for the train. Swapping out a problem unit for a good one means that the train stays in the barn for the shortest time possible,” explained Joseph Bromfield, Chief Mechanical Officer, Department of Subways. So, as temperatures rise you can be certain that an army of men and women in NYC Transit’s maintenance facilities are working diligently to keep you comfortable as you travel around the City.

Newer AC system on top of subway car
Newer AC system on top of subway car
Older HVAC system
Older HVAC system