If you ride several different subway lines, you might have noticed a recent trend: one subway car model seems to have more busted A/C units than any other type. "The majority of the hot cars that we've seen over the past couple of days have been the R62As," said MTA spokesman Kevin Ortiz. You probably know them as the 1 and 6 trains — as does the riding, tweeting public: @NYCTSubway just FYI, car 2432 on the 1 doesn't have AC this afternoon — Chris Lorenz (@Tophala) July 25, 2016 @NYCTSubway No air conditioning in car #2405 on the 1 Train. — Chris O'Leary (@ohhleary) July 26, 2016 @NYCTSubway can you PLEASE fix the air conditioning on the 1 trains? 2nd time time today my commute has been covered in sweat. — Emily Nash (@NasherME) July 25, 2016 The R62As date back to the Reagan Administration, and therein lies the problem. "The technology at the time provided for one compressor for each of the air units in the car," Ortiz said. "So if you lost that one compressor, you basically lost all of the air for that entire car."

Newer cars — or older cars that have been overhauled — are built differently. "They have separate HVAC systems, where if one fails, you can use another within that car," said Ortiz. And repairing them is simpler: the HVAC systems "are easily removable from the top of the trains." Almost like Lego, a broken HVAC unit can be popped off a train, repaired, and popped back on. But "that's not the case with the older technology cars," he said, "where you have to work on the entire component as a whole to address it." Meanwhile, the city is in the thick of a heatwave, which usually exacerbates so-called "hot car" complaints. "Yesterday we had 12," said Ortiz. Which may not sound like a lot of complaints, when you consider that the system has more than 6,300 cars. But when the percentages work against you, it's miserable: boarding a train with broken A/C feels like walking into a wall of hot, molten misery. But you are not powerless, sweaty, beleaguered subway rider.

If you experience a hot car, make note of the car number, line, and time of day, and let the MTA know: Tweet at NYCTSubway, email the agency through the portal on its website, or call 511. "Once we receive notification that there's an issue with a car," Ortiz said, "then we will take it out of service at the completion of its next run."what is the best window ac units Where the Hot Subway Cars Arehome ac unit prices Another factor dogging the R62As: they're reaching the end of what the MTA calls its scheduled maintenance cycle. how much for a ac unitEvery four, seven and 14 years, all subway cars, regardless of model, receive major overhauls. New A/C units typically get put in during the year seven maintenance work. And this is the year that the R62As are undergoing their seven year overhaul.

So relief is coming — albeit slowly, like a local train on crowded stretch of track. Ortiz said it takes about 20 days to overhaul and test a car. And with over 800 R62As in service, the process of fixing them will take "a couple of years." Read more Gas Pains coverage: Destination: 35 MPG We wanted to determine which is a greater detriment to fuel economy: driving with the windows down or driving with the air conditioner on. The results of this test were surprising. We figured that the fuel economy of a modern car would suffer more from the extra aerodynamic drag that comes from driving with a vehicle’s windows open than by the additional load on the engine from running the A/C compressor. With the sedan we tested, that wasn’t the case at all.If you buy into global warming being caused by humans and think that melting ice caps will be detrimental to the habitat of arctic wildlife, then insisting on frosty comfort in the cabin of your car will kill far more baby seals than does rolling down the windows.

The losses caused by running the A/C decrease at higher speeds because the engine produces more power as revs increase, reducing the burden on the engine of running accessories such as the compressor. Driving with an open sunroof and closed windows is also wasteful, although not as much as windows-open mode. And while driving with the windows down is more fuel efficient than running the A/C, you could lose an arm hanging it outside of the car like that. In a couple of forums where we are working on kit cars with VW air cooled engines and therefore little room for conventional air con compressors etc we are looking at electronic means of getting cooled air into the interior and peltier devices have been mentioned. There is the advantage that we have small two seat cabins, about 2,5 cubic meters so not a lot needed but with ambient external summer temperatures of 30c to 42C and a large, almost horizontal windscreen, internal temps can get as high as 60c+. I have looked at a few kits and assemblies and I can see where we could use and even utilize these but how COLD if one could expect from say a 6.5A to 10A unit using something like a CPU cooler heat sink and fan.

Alternative idea is to cool the fluid with Peltier devices in an insulated container (like a cool box) and then use that to construct a pumped cooled fluid system passing the pipes through the cooled fluid and a matrix in the car with a fan as normal and again use the heated side when needed for warming the car, when not needed the heat would be vented away or the whole thing just switched off. A/C using peltier devices, is it feasible' Any brain storming ideas would be very welcome as I can get my head around the engineering side but electronics are limited to 12vDC car systems. My Mercedes air con delivers as low as 5c at the vents but that is too cold and it is a much larger area. May be possible, but not viable. Have a look at the Datasheet of a TEC1-12714S from Thermonamic Module. This is a 62x62x4.9mm³ PE, maximum current 14A, maximum voltage 17.2V. It is one of the most powerful devices on the marked. The first problem a PE has is that it also conducts heat from the warm to the cold side, and this linearly depends on the temperature difference.

While the heat pumping power is about constant, this means that the effective heat pumping power has it's maximum when there is no temperature difference. As soon as the difference rises, heat is also conducted backwards, and at some point, this "back-flow" equals the pumping power. So, the first diagram shows a linear dependency between temperature difference DT and effective pumping power Qc: However, as long as it's really hot inside the car, the full pumping capacity will be available. Note also that the maximum pumping power is about 140W for 14A and DT=0. If you have a look at the second diagramm, this current occurs at about 12V. So the PE consumes 12V*14A=168W of electrical power, already more than what it pumps. If there is a temperature difference, effective pumping power decreases while power consumption increases due to higher voltage. So, if t's really hot outside (40°C) and you want 20°C in your car, this PE will only have an effective pumping power of 100W. Also, you have to dissipate pumping power plus consumed power at the outside, so 268W for the last example.

Up to now, we did not say much about how much power you need. A hair dryer typically has about/above 1000W, which heats your bath room only slowly. 100W may me much for a solder iron, but it's quite negligible for heating a room. The sun heats your car about 1000W/m². I did not find numbers about car ACs, but is well-known that an AC takes some kilowatts from your engine. You may not notice it on most cars, but I do. I've only about 50kW, and on the highway with a slight slope, I sometimes call the AC switch my "inverse turbo boost". For sure, the AC takes about 2-5kW. As the pumping power can be higher than the consumed power (see this discussion, though not answered yet), you can estimate the pumping power to at least 3kW. 3kW, that's 30*100W, so 30 peltier elements each consuming 168W, being 5040W or 420A at 12V. Furthermore, you have to dissipate 30*268W=8040W of heat somehow. I think, the numbers of my last paragraph show that it would be better to think of a compressor-based AC solution...