cabin heating

[snowathlete]

Well those are the arguments with regard to warm air in the cabin. But the issue is just as much about engine wear, DPF wear, and fuel economy as it is cabin heat for me now. A PTC is easy and effective, and cheap too, but you don't get those additional benefits that you get from warming the engine instead.

 

You're right about the blowers, people always put them on fast in a cold car but there's not a lot of point to it until there is some heat to have from the engine.

 

Regarding the VAG PTCs, they have three elements, 30, 60 and 80 amps (combined I presume), so quite a lot of power really. The smart ones have their own in built controller which takes account of the battery, alternator, and other loads and switches the three elements on/off depending on several factors. The dumb ones are controlled by the ECU (presumably you have to install software) but dont take as much into account.

 

The coolant heaters tend to be 2 or 3kw, whereas the contact heaters are much less, usually 200-600w, something like that. But of course these both run off mains so there are no car battery concerns, except some trickle charge the battery because they turn on the fan to pass heat to the cabin before the engine is even started. And Webastos are something like 4 or 5 kw uses some battery power but most of course comes from burning diesel.

 

 

Edited 1 February, 2018 by snowathlete

[langers2k]

A PTC heater uses a lot of power initially but quickly reduces as the element heats up.

 

Smart and dumb versions can use 1, 2 or 3 elements, the difference being whether the PTC heater or engine ECU makes that decision. Both the ECU and smart PTC are on the CAN-bus so will have access to the same data to decide.  The ECU should already have the software needed to control the PTC heater, it just need the additional wiring, a couple of relays/fuses and coding to say the PTC is fitted.

 

A properly fitted diesel power heater should monitor battery condition, fuel level and lots of other parameters. If any are out of range or low it will shut off.

[voxmagna]

Those power figures are impressive and explain why you need a lot of alternative power to get an engine and car cabin even warm when it's freezing outside. 60 Amps is serious wiring and safety protection. I guess the diesel fueled heater will only be using battery for fans, ignition and a fuel pump? That's the advantage of catalytic heating from propane, not much juice other than ignition, fan and control, but you need somewhere for the cylinder, although for just auxiliary cabin heating supplementing the car heater you wouldn't need much. I think boats are using these?  If I'm idling with a cold car in traffic, the alternator won't match those kind of high electrical loads. Then you need to drive faster and the engine will heat up anyway? If your vehicle is regularly parked and used near mains, that is the most obvious power source to tether. To keep things safe and wire sizes down, 110 Volt might be best. 12volt is just so lossy and copper hungry. At least the truckers have 24 volt.

 

I once considered getting waste heat from the exhaust down pipes on a motorcycle for heated clothing. Liquid through a coil with a heat exchanger somewhere offered the most compact solution, but I couldn't work out what to do once the liquid got over 100C other than designing to use steam as the heat carrier.

[snowathlete]

Diesel powered heater, also a coolant pump. That's the thing though right - the Superb can be fitted with a diesel powered heater which heats the coolant, so it must surely be possible to alternatively fit an electric coolant heater instead. Even if a diesel powered heater can reach 75C+ to open up the DSG stat, it isn't always going to because it might be too cold out or not switches on for long enough, yet the system is still fitted. This thinking does encourage me that an electric coolant heater should be doable somehow.

 

I'll be honest, I don't really understand voltages, or electrics that much. I would like to but I don't get it much. I only know that it matters :-)

 

I like your motorcycle exhaust idea, I can visualize all that steam coming off behind you.

 

[langers2k]

1 hour ago, voxmagna said:

Those power figures are impressive and explain why you need a lot of alternative power to get an engine and car cabin even warm when it's freezing outside.

 

PTC draws a maximum of 1KW and has a 100a fuse, there is a great graph in this post showing both current consumed and alternator load. When fitted properly, the PTC heater will shutdown if the alternator load is too great. The ECU can also raise the idle speed to help.

 

10 hours ago, snowathlete said:

No diagram I can find for the Superb

 

This shows the some of the parts used by a Superb with PR-9M9 (webasto aux heat) fitted: http://www.oemepc.com/skoda/part_single/catalog/sk/markt/CZ/modell/SUP/year/2014/drive_standart/768/hg_ug/819/subcategory/819070/part_id/2539843/lang/e

 

There is no mention of any engine restrictions which suggests that all should be fine, there are also plenty of autoscans online showing CFGB engines with both DSG gearboxes and diesel aux heaters fitted so I'd be surprised if it wasn't possible.

 

If you're seriously considering this, you should pay for a few hours access to https://erwin.skoda-auto.cz - you should be able to get all the wiring and other information needed so you can find out exactly what's needed to retrofit. If nothing else, it should confirm where the coolant is heated and if any other pumps/valves are used.

[amwphotos]

Has anyone tried the cheap electric parking heaters you can get off eBay and the likes? Like the one in the photo

[voxmagna]

Interesting, Russian text & shipped from China. A lot of heat to get rid of in a small space. I hope the pump is good and reliable? I liked the look of this one too, Being round it seems more the business and the body assembly sealing is circular. Cheaper too and open to offers:

https://www.ebay.co.uk/itm/220V-3000W-Automotive-Truck-Engine-Pump-Coolant-Heater-Preheater-w-European-Plug/112706260945?hash=item1a3dd10fd1:g:L-YAAOSw88xaPcgE

[snowathlete]

2 hours ago, langers2k said:

 

PTC draws a maximum of 1KW and has a 100a fuse, there is a great graph in this post showing both current consumed and alternator load. When fitted properly, the PTC heater will shutdown if the alternator load is too great. The ECU can also raise the idle speed to help.

 

 

This shows the some of the parts used by a Superb with PR-9M9 (webasto aux heat) fitted: http://www.oemepc.com/skoda/part_single/catalog/sk/markt/CZ/modell/SUP/year/2014/drive_standart/768/hg_ug/819/subcategory/819070/part_id/2539843/lang/e

 

There is no mention of any engine restrictions which suggests that all should be fine, there are also plenty of autoscans online showing CFGB engines with both DSG gearboxes and diesel aux heaters fitted so I'd be surprised if it wasn't possible.

 

If you're seriously considering this, you should pay for a few hours access to https://erwin.skoda-auto.cz - you should be able to get all the wiring and other information needed so you can find out exactly what's needed to retrofit. If nothing else, it should confirm where the coolant is heated and if any other pumps/valves are used.

 

Thank you for the link(s). There's also an item listed "solenoid valve for vehicles with auxiliary heater" which obviously has some control over the coolant flow when the Webasto is fitted. It's not in the Webasto diagram though, so hard to guess it's purpose. Does it allow coolant to bypass the thermostat, or does it shut off hot coolant to the cabin if it gets too hot, or something else?

http://www.oemepc.com/skoda/part_single/catalog/sk/markt/CZ/modell/SUP/year/2014/drive_standart/768/hg_ug/819/subcategory/819072/part_id/2561566/lang/e

Good idea about erwin if I go ahead.

 

[snowathlete]

2 hours ago, amwphotos said:

Has anyone tried the cheap electric parking heaters you can get off eBay and the likes? Like the one in the photo

 

This is the sort of thing I'd be looking to fit, though I may pay a little more for one that comes with a ready cable/connector etc. Would love to hear if anyone has already fitted one of these mains powered coolant heaters and if they had any problems.

Edited 2 February, 2018 by snowathlete