Class 185 air con issues

[Tracked]

Wait.... Underfloor heating? Do other trains have that?

180s, but not intentionally?

Did Chesterfield to Bristol on a HST July 2018 where the aircon had failed in my carriage, Voyager on the journey back was absolutely rammed due to a thunderstorm taking out the signalling centre at York, so I was stuck in the vestibule with a few dozen others and no aircon (and the toilet ) from Birmingham to Chesterfield via the Derby diversion.

Can't remember ever having had an issue with aircon on a 185, despite getting them on the way to/from work for a few years before this pandemic thing happened, it's usually TPE's overlong announcements that get my blood boiling

 

[ic31420]

If it was below the carriage it was most probably the radiators. On a hot day they work extra hard keeping the cooling system for the engines cool. The HVAC is on the roof and isn't normally loud.

Seemed to be coming from the roof. Probably not helped by the trainshed roof and the fact I don't usually encounter them in covered stations.

 

[Llama]

Are you sure it's actual underfloor heating on 195s and not the coolant pipes that run along the lower side of the saloons. A little bird on Newton on the Heath told me that those pipes had to be drained very soon after entering service due to coolant leaks, and the associated coolant pumps isolated to stop them running 'dry' (hence all the 'HVAC CB' faults on the TCMS and circuit breakers taped open)...

And yes the air con is weedy on 195s as it seems it has been modified to only cool by a maximum of ~7°C compared to ambient temperature. The temperature sensors are not the most reliable - I've had two coupled 195s in multi with one unit reading external temperatures more than 10°C apart, one was 'cooling' from what it thought was 35°C down to 28°C in the saloon, and yes it was that that warm in that unit, perfectly fine in the other one which was 21°C inside, actual outside temp was about 25°C. Traincrew have no way of altering the temperature of the saloon aircon on 195/331 units.

Plus if a 195 is left berthed but running without a drivers key in for 15 minutes or more it'll go into 'sleep mode' which knocks off the air conditioning throughout the unit - all very sensible but then the air conditioning needs to be manually switched on again otherwise it'll just be on 'vent' - that little detail is lost on a lot of drivers. The same happens if a unit has been put into 'ECS' mode - A/C then needs manually switching on. The 195 training course never mentioned stuff like this.

 

[MattRat]

Are you sure it's actual underfloor heating on 195s and not the coolant pipes that run along the lower side of the saloons. A little bird on Newton on the Heath told me that those pipes had to be drained very soon after entering service due to coolant leaks, and the associated coolant pumps isolated to stop them running 'dry' (hence all the 'HVAC CB' faults on the TCMS and circuit breakers taped open)...

.......

Plus if a 195 is left berthed but running without a drivers key in for 15 minutes or more it'll go into 'sleep mode' which knocks off the air conditioning throughout the unit - all very sensible but then the air conditioning needs to be manually switched on again otherwise it'll just be on 'vent' - that little detail is lost on a lot of drivers. The same happens if a unit has been put into 'ECS' mode - A/C then needs manually switching on. The 195 training course never mentioned stuff like this.

This just sounds like an overly complicated system that was obviously going to cause problems.

 

[Bletchleyite]

As someone who has years of experience using 185s, I can safely say failing air con is not a new issue at all. They're probably second behind the 158s if I'm honest. It's never aided by traincrew insisting on leaving saloon end doors open to try and circulate air across carriages, which simply makes the aircon on the neighbouring vehicle work even harder to minimal effect on the next carriage.

Yet the 350 aircon is very reliable. Same units, no?

I think, ultimately, you're asking a lot for a diesel engine to drive an aircon unit of the size required. EMUs seem to have issues far less often, I suspect due to the readily available, consistent supply of electricity.

These things have roughly twice the engine power of other comparable 100mph units (i.e. Turbostars). I don't think this should really be an issue at all.

 

[Llama]

This just sounds like an overly complicated system that was obviously going to cause problems.

The issue I was told was poor quality plumbing of said pipes causing coolant leaks into the saloon.

I'm fairly sure there wouldn't be actual underfloor heating on 195s. If there is, it's unnecessary by testament that the HVAC saloon low-level coolant circuits have been largely isolated/drained pretty much since new and there aren't reports of poor saloon heating.

The cab heaters weren't effective enough when it got really cold last winter though, but they're not coolant/waste engine heat related - there's an electric fan heater which emits warm air from the lower desk panels and the cab HVAC will pump out warm air just as the saloon HVAC can do. Even putting on the demister for the radiated heat that provides made an improvement to the cab temperature when it was really cold.

 

[driverd]

Yet the 350 aircon is very reliable. Same units, no?

...These things have roughly twice the engine power of other comparable 100mph units (i.e. Turbostars). I don't think this should really be an issue at all.

I never worked 350s so I can't really comment - I'm just comparing to other units I have worked, as a rule of thumb, EMUs are relatively reliable in terms of the auxiliaries vs DMUs, although I'm sure there will be exceptions too.

170s aircon isn't brill either, they just seem more reliable than 185s, in my experience. It's certainly not rooted in any known fact that EMUs have more reliable aircon, just personal experience and a rough idea of how the system works. In the summer, you're asking an engine that's already working hard and often battling to cool itself (which requires further use of engine power) to then drive a hefty air con system in addition. EMUs, conversely, are only limited by the power available in the grid. As I say, it's a suspicion, not a fact - more than happy to be corrected!

 

[Llama]

Judging by the frequent alternator faults on 195s I'd say that's a pretty reasonable observation.

 

[ic31420]

I suppose an emu generally vibrates less, has a smoother power supply and perhaps, in general, run over better track that doesn't rock and bash them about as much.

 

[Llama]

Not sure that's necessarily the case for 331s which bang and crash about due to the poor ride even on decent track.