[OneEV]

So because it was too hot, you went and crippled the Bolt's HVAC system by turning on recirc.

Which I've already established will IMMEDIATELY (within seconds of pushing the button) spike the heater's power way up.

Thus making comparison of the Bolt's system against your setup COMPLETELY invalid.

In your shot, you've got an ambient temperature of 43F ambient. There's no way in **** you're seeing 2400W average unless you either opened the windows or disabled recirc.

I get far lower average power consumption at only 20F ambient.

what the h are you talking about ... I have tried with recirc without recirc...the only thing recirc does is uses the interior air and "recirculates" it . Using LESS energy to maintain heat best it can


When I turn off recirc on PTC then I also leave it off Cars heater... all things equal.

 

[PLP]

I happen to be the only person that has provided proof on something that isn't exactly rocket science. I max out at 1,000 watts... the Bolt max es out at 7,500 watts... so no shaat sherlock I am going to get better range.

But you are not comparing same scenarios. That where it hurts most folks here.
You will shout in ALL CAPS, with large Bold letters that you accomplished something, but the data you compare between OEM setup and your PTC are two different scenarios.

Besides, however you want to word it - there is no logical explanation why your 1 kW would be enough for doing same job what 7.5 kW does.
Energy of 6500 W is huge loss. There is no explanation for it, meaning I cannot find any plausible explanation for it.
Even assuming OEM system is poor design, and it is, it is still not as bad to simply drop 6500 W somewhere in between.

Yes, I see, you gained 18 miles on full charge. Is it a lot or not? That is debatable. One could say - drive a bit slower. No can do here. I get it.

All possible problems you created with your setup (strains on the DC/DC converter, OEM 12 V battery, lack of filter, possible melting of the blower, no cabin filter...).
And the investment of time and money.
Yes, that is how great ideas are born.

To really prove it, you would have to spend at least two days of same driving, same weather and settings, one with PTC the other with OEM, while doing extensive data tracking and logging.
Almost laboratory setup like.
I can see that even with -10 C (+14 F) on a longer day of driving I get the OEM system down to 1500-2000 W on most times. Sure, hard to prove a point here.

 

[MisterJJ]

I max out at 1,000 watts... the Bolt max es out at 7,500 watts

Sounds like you are doing the equivalent of forcing the stock system to run at only 1,000 watts, which uses less energy, of course. With an additional side benefit of more instant heat.

I wonder if limiting the power of the stock system would create similar results with less possible issues.

 

[PLP]

Sounds like you are doing the equivalent of forcing the stock system to run at only 1,000 watts, which uses less energy, of course.

But that is the bad side of it.
Any power to OEM heating system is a big waste due to the fact it must first warm up the whole system and coolant within. This is a big heatsink.
Surely, at lower power load the coolant is at lower temp, so you experience less heat exchange with ambient, what overall results in less losses. Yet still, ideal would be NOT to deploy OEM at all.
Use PTC only.

 

[EV Engineering]

I have wondered - might propane be simpler for this application? (no need for a pump for example). Biggest issue with any combustion approach is you need to add some exhaust plumbing, and also potentially air intake plumbing.

Also probably some condensate plumbing for a highly efficient system - acidic condensation is a problem for high-efficiency condensing systems.

Solve the exhaust/combustion air intake challenge and you've probably also got an opportunity to use the same solution for a less effective (but also much less extreme) HRV system to maximize ability to stay on recirc without fogging.

That is what I'm working on using fuel exhaust as heater for battery... it will not have a lot of power but it will keep more than happy battery in cold weather....flow true coolant something similar to what boiler is doing but I will be using venture pipes for maximum exhaust heat transfer and I have already variable pump that will keep coolant flow for battery in check....
Propane is not my favorite fuel....living in the Midwest bio diesel is easily obtained....Unit I will be using has altitude and combustion chamber sensors for optimal burn rate....and it is certified for all 50 states....also it has catalyst converter for near zero emissions. It is very expensive Unit that I use for other projects and marine applications....
Pump will still be necessary for cabin heater and battery heater... I will have independent control over my setup and it will not interfere with my setup.... For now I'm playing with when air conditioning is called to cool down battery....and once I find it I will adjust my calibration for battery heater loop. Exhaust when pushing 5000 watts of heat to coolant is producing on exhaust side 6 inches from exhaust outlet 128°F hot air and from my calculations it is giving around 400-750 watts of heat transfer to coolant using exhaust heat... I could get even more but I don’t want to eliminate catalyst converter....

 

[EV Engineering]

If I did the math right, we are talking about 85% efficiency.
Biodiesel is about 34 MJ/l and from the above it looks like 8000 W from a liter of fuel.
Joules per s is a W, 3600 seconds per hour, and here and there - about 29 MJ in 8000 W during 60 minutes.
28.8/34.0=84.7%.

That is quite good.
If it is quiet and does not smell badly, might be a decent alternative to electric energy.

Reason for not getting over 85% efficiency is because this unit uses catalyst converter and for this to operate properly they have to make it less efficient ( more heat to exhaust instead of combustion chamber coolant heater)
It has no fumes and no smell ( but what they say it is not killing you what you can smell but what you can't)
And you are right on the money with your calculations.... I could get better efficiency with dinosaur diesel or kerosene...but bio diesel is what my setup will be running.....
I do still agree that cleanest heating is electricity but using 5-8 kWh for 2 hours of driving is no go with battery size in Bolt EV.
I have 4 EV projects done this way for customers ...
Now my new idea is to harvest exhaust heat on top of fuel coolant heater .

 

[gonnabolt]

A test I have not seen trotted out to distinguish stock heater range vs PTC heater range would be run the car all day from full to empty with stock heater, and again with PTC heater. Taking notes each day, even better with multiple days of each, along with ambient temp and cabin temp noted (hopefully identical for each run). Do that and report back, please. Using the infotainment display for short runs tells nearly nothing.

 

[OneEV]

Yes, I see, you gained 18 miles on full charge. Is it a lot or not? That is debatable. One could say - drive a bit slower. No can do here. I get it.

No not debatable.. 18 Miles and NOT having to slow down is significant.


BTW Looks like once we get temps near 50 then the PC heater won't make as much difference because running either heater will only be for short time anyway.

 

[OneEV]

A test I have not seen trotted out to distinguish stock heater range vs PTC heater range would be run the car all day from full to empty with stock heater, and again with PTC heater. Taking notes each day, even better with multiple days of each, along with ambient temp and cabin temp noted (hopefully identical for each run). Do that and report back, please. Using the infotainment display for short runs tells nearly nothing.

So we can ignore everyone's Posts about their range then unless they ran their Bolt to empty..yeah OK then

 

[Entropy512]

A test I have not seen trotted out to distinguish stock heater range vs PTC heater range would be run the car all day from full to empty with stock heater, and again with PTC heater. Taking notes each day, even better with multiple days of each, along with ambient temp and cabin temp noted (hopefully identical for each run). Do that and report back, please. Using the infotainment display for short runs tells nearly nothing.

Yup, and running the Bolt in the most efficient manner possible when using the builtin heat. For example, recirc on and only tapping the defrost/defog button when fog appears just long enough to clear the condensation. Log heater wattage used by the Bolt for the entire run, and also monitor AC wattage in case the AC kicks on for whatever reason.

Reason for not getting over 85% efficiency is because this unit uses catalyst converter and for this to operate properly they have to make it less efficient ( more heat to exhaust instead of combustion chamber coolant heater)
It has no fumes and no smell ( but what they say it is not killing you what you can smell but what you can't)
And you are right on the money with your calculations.... I could get better efficiency with dinosaur diesel or kerosene...but bio diesel is what my setup will be running.....
I do still agree that cleanest heating is electricity but using 5-8 kWh for 2 hours of driving is no go with battery size in Bolt EV.
I have 4 EV projects done this way for customers ...
Now my new idea is to harvest exhaust heat on top of fuel coolant heater .

Based on how I understand how you're describing it:
The coolant heat exchanger and the combustion chamber are integrated with each other, then followed by a catalytic converter, then by exhaust with no further HX?

Yeah, putting an HX that preheats the coolant from the cat exhaust should increase efficiency, but you need to be careful that when starting to condense out the exhaust, you handle the rather acidic condensate properly. (This is a challenge with high-efficiency condensing boilers that are so efficient they condense the water vapor out of the exhaust.)

You might possibly find better efficiency improvements at that point for total system effiiciency than just making the combustor more efficiency - most notably as I've mentioned before by maximizing recirc by finding ways to control humidity without losing heat. As I've mentioned, either a dehumidifier or an HRV ( see DIY Heat Recovery Ventilator (HRV) Plans for one example of an HRV - one to handle the Bolt efficiently would likely be much smaller. Take a look at Dan Achim's setup in the comments that was coincidentally posted only a day or two ago, I like his geometry that gets proper counterflow over a greater percentage of the unit, although I wonder if the tape he's using to seal the joints is going to create gaps that kill efficiency without a huge amount of thermal paste or similar material...

 

[EV Engineering]

Yup, and running the Bolt in the most efficient manner possible when using the builtin heat. For example, recirc on and only tapping the defrost/defog button when fog appears just long enough to clear the condensation. Log heater wattage used by the Bolt for the entire run, and also monitor AC wattage in case the AC kicks on for whatever reason.


Based on how I understand how you're describing it:
The coolant heat exchanger and the combustion chamber are integrated with each other, then followed by a catalytic converter, then by exhaust with no further HX?

Yeah, putting an HX that preheats the coolant from the cat exhaust should increase efficiency, but you need to be careful that when starting to condense out the exhaust, you handle the rather acidic condensate properly. (This is a challenge with high-efficiency condensing boilers that are so efficient they condense the water vapor out of the exhaust.)

You might possibly find better efficiency improvements at that point for total system effiiciency than just making the combustor more efficiency - most notably as I've mentioned before by maximizing recirc by finding ways to control humidity without losing heat. As I've mentioned, either a dehumidifier or an HRV ( see DIY Heat Recovery Ventilator (HRV) Plans for one example of an HRV - one to handle the Bolt efficiently would likely be much smaller. Take a look at Dan Achim's setup in the comments that was coincidentally posted only a day or two ago, I like his geometry that gets proper counterflow over a greater percentage of the unit, although I wonder if the tape he's using to seal the joints is going to create gaps that kill efficiency without a huge amount of thermal paste or similar material...

Thanks I will look into it...

 

[OneEV]

So 121.8 / 36.7 = 3.31 miles/kWh I ran Just the PTC today. As you can see plenty warm inside the vehicle at 78 degrees. (Climate settings 1%)


I had 26 total Stops, passengers getting in and out, and waiting for passengers. so 3.3. excellent ..temp was 32 when I started 38 when I ended

On a Ful 60kWh battery I could have gottne a total range of 60 - 36.7 = 23.3 kWh left = 23.3 x 3.1 = 72 More miles . 121.8 + 72= 193.8 ...for a average 35 degree day , 26 stops and running snow tires.


So I took photo of my home charger 3783 kWh ...lets see what it says in the morning /later tonight .. it should ad 36.7 or thereabouts ...total 3819.7

 

[phuber]

Thanks for a great idea EV One. After three tries, I was able to purchase a 2,000 watt inverter (Amazon sent two 230 volt versions of the one you purchased). I placed the bluetooth controlled invert under the floor mat where the passenger's feet would be placed and ran 5-feet of 4AWG wire to the battery. The negative terminal of the inverter is connected to a dash mounted display showing how much current is being drawn from the 12-volt battery.

I figure that the 2,000 watt modified sine wave inverter must be more efficient than the 1,200 watt pure sine wave unit I has previously been using as the 1,200 watt version kept cutting in and out.

I mounted the heater to a piece of aluminum and filled in the gaps on either side of the heater. The heater works well and I look forward to seeing how this approach helps my long-range driving. I plan to preheat the car before leaving an reheating when charging. I hope to be able to skip a stop in the 290-mile trip from my home to Northern Virginia. I very much appreciate your original post and the great idea.

 

[phuber]

I also insulated the plumbing going to the stock under the hood heater and plan to also insulate the stock heater as well. Judging from how hot they are to the touch, there is bound to be a significant loss of efficiency going on there which may explain part of the difference between your solution and the Bolt heater.

 

[OneEV]

Thanks for a great idea EV One. After three tries, I was able to purchase a 2,000 watt inverter (Amazon sent two 230 volt versions of the one you purchased). I placed the bluetooth controlled invert under the floor mat where the passenger's feet would be placed and ran 5-feet of 4AWG wire to the battery. The negative terminal of the inverter is connected to a dash mounted display showing how much current is being drawn from the 12-volt battery.

I figure that the 2,000 watt modified sine wave inverter must be more efficient than the 1,200 watt pure sine wave unit I has previously been using as the 1,200 watt version kept cutting in and out.

I mounted the heater to a piece of aluminum and filled in the gaps on either side of the heater. The heater works well and I look forward to seeing how this approach helps my long-range driving. I plan to preheat the car before leaving an reheating when charging. I hope to be able to skip a stop in the 290-mile trip from my home to Northern Virginia. I very much appreciate your original post and the great idea.

Morning Phuber It's really nice having the heat come out of the same vents. I am finding that using recir I am still getting fogging when I have a passenger in the car ... when I am alone I can use recir and crack the passenger window ..just a tiny bit. Actually, with temps in the 30's don't even need recirc on as the heater warms the car enough anyways

So best results seem to be .... temp set off (LO) , fan at 3.


VERY IMPORTANT.. Make sure you ALWAYS TURN IT OFF if you are going to be out of car for long periods of time with the car off. 1 .. You don't want the heater still running with no air passing through and 2. you run the risk of draining your 12volt if you forget to turn it off.

IF ..you get the Battery Charging Message is simply because you are running too many watts ... so if the Fan is at 7 turn it down to 3, you may need to turn the rear heated seats off , or steering wheel heat ... I haven't had the message in a month .. I can run 1 rear heated seats, 1 front heated seat, heated steering wheel , fan set at 3 with the ceramic heater running without any issues.

The only thing that concerns me about your setup is the 5 foot long cables..keep us posted how it is working.


Have you checked the temperature of the heater .. ?




I'm already trying to sort out how to run it's own fan instead of the Cars fan...I want to turn the Cars HVAC COMPLETLY off . wondering if there is enough room to add a high-powered fan on top of the Heater.. ?that plumbing I believe just extends another foot into the "engine bay" . At that point we have the Air Inlet.. which is also an area to look at .. can we point the air inlet at those HOT electronic ..so to kind of preheat the air coming in ?

Or can we figure out how to get another 300 watts from the Car to run a small 300 watt PTC heater right at the air inlet to preheat the in coming air?

 

[phuber]

Here is a link to the inverter. It fits very nicely under the floormat at front part of the passenger footwell: Amazon.com: Kinverch 2000W Continuous/ 4000W Peak Power Inverter 3 AC Outlets 12V to 110V Car Converter with USB Port and Bluetooth APP Remote Control: Car Electronics

Here is a link to the 4AWG wire used to connect to the battery:

Amazon.com: WNI 4 Gauge 10 Feet Black 10 Feet Red 4 AWG Ultra Flexible Welding Battery Copper Cable Wire - Made in The USA - Car, Inverter, RV, Solar: Electronics

Amazon.com: WNI 4 Gauge 10 Feet Black 10 Feet Red 4 AWG Ultra Flexible Welding Battery Copper Cable Wire - Made in The USA - Car, Inverter, RV, Solar: Electronics

www.amazon.com

Here is a link to the current guage used to keep up with the current draw and voltage in the 12-volt battery

Amazon.com: bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt: Industrial & Scientific

Buy bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt: Multimeters & Analyzers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[phuber]

Good morning OneEV, I'll take some measurements next time I am on the road for any extended time (most of my driving is local these days). Also, our temperatures are fairly moderate compared with what you face. I am no expert but it seems it would be fairly difficult to install much of any meaningful fan or get more juice from the car. You identified a key area of inefficiency on our Bolts with the design of the heating system. I would doubt that the fan itself provides as much room for improvement. Only possible additional savings may be in the efficiency of the inverted. A friend of mine found an efficiency curve for an inverter that showed it to be less efficient as it neared capacity. Thus, I oversized the 2,000 watt unit and degraded from pure sine wave to modified sine way on purpose in hopes that these changes would improve the efficiency of my set up. I'll let you know how things go on the wire. If I had it to do over, I would probably install 2 AWG rather than 4 AWG.

Hope this helps.

 

[GJETSON]

So best results seem to be .... temp set off (LO) , fan at 3.

I'm already trying to sort out how to run it's own fan instead of the Cars fan...I want to turn the Cars HVAC COMPLETLY off .

OK. Now I am confused. You say you have the temperature knob turned to LO, and you would like to have the cars HVAC completely off. There is a button that does exactly that. On my 2017, the HVAC button on the screen should be unlit. If it is not lite, the AC, and cabin heater, do not run. The fan, and recirculate flap, work without the HVAC system on.

 

[OneEV]

OK. Now I am confused. You say you have the temperature knob turned to LO, and you would like to have the cars HVAC completely off. There is a button that does exactly that. On my 2017, the HVAC button on the screen should be unlit. If it is not lite, the AC, and cabin heater, do not run. The fan, and recirculate flap, work without the HVAC system on.

interesting Gjetsen... the Only way fan works for me is if HVAC power "on" button is activated... So I turn "ON" then turn the temp knob all the way to the left to "LO" ..


If the HVAC is off and I turn to turn just Fan on then Power ON comes on ...

 

[GJETSON]

The ON button is for the recirculate flap, and fan too, not just the HVAC. As long as the orange light for the HVAC is off on the touchscreen, it doesn't matter where you set the temperature knob, the HVAC is off.

Don't tell me you haven't got Torque Pro? If you did, you would know this!

Just went out and took these two shots. Sorry for the overhead light glare on the touchscreen. That was the only way the orange lights on the touch screen would show up.