Cold Climate Auxiliary Heat From Harvester ICE

[Last_Fun-tier]

One aspect for consideration with the Harvester range extender, is the free availability of heat generated by running the ICE.

My suggestion, especially for those like me who live in cold climates, such as Alaska, where temperatures can hover in the -15 to -40°F range for long periods on end, the ability to heat the cabin of the vehicle while using the range extender would be a huge benefit. Plus, the heat is already freely produced when using the range extender to charge the batteries.

A feature like this could reduce trepidation with purchasing an electric vehicle in cold climate locations. Thank you.

 

[dsoul79]

Additional option for the heat, warm the battery packs in colder climates for better range etc. Could this be done similar to radiant floor heating? And actually radiate the heat on up into the cab?

 

[J Alynn]

Additional option for the heat, warm the battery packs in colder climates for better range etc. Could this be done similar to radiant floor heating? And actually radiate the heat on up into the cab?

This has been tossed around before but never heard anything from SM or other EV smart people that could say if it was doable. I was a big fan of this but not sure how it works. One suggestion was if the cooling tubes get warm enough on return flow through heat pump could the return route be directly on floor bottom to do as you said.

 

[Last_Fun-tier]

This has been tossed around before but never heard anything from SM or other EV smart people that could say if it was doable. I was a big fan of this but not sure how it works. One suggestion was if the cooling tubes get warm enough on return flow through heat pump could the return route be directly on floor bottom to do as you said.

Thank for the reply. I used to have a class B motorhome that had a hot plate attached to the engine block with supply and return waterlines that served as an auxiliary water heater. After a long day of driving one could take a hot shower just from the hot water supplied by the engine. Of course there was a secondary hot water heater, but the hot plate is one example of capturing the waste heat from the engine for warming purposes.

 

[JohnT]

One aspect for consideration with the Harvester range extender, is the free availability of heat generated by running the ICE.

My suggestion, especially for those like me who live in cold climates, such as Alaska, where temperatures can hover in the -15 to -40°F range for long periods on end, the ability to heat the cabin of the vehicle while using the range extender would be a huge benefit. Plus, the heat is already freely produced when using the range extender to charge the batteries.

A feature like this could reduce trepidation with purchasing an electric vehicle in cold climate locations. Thank you.

This is my concern as well, live in Montana and worried about battery usage. I heard they lose up to 30 to 40 percent of capacity at colder temps. Thanks

 

[DaveGunter]

This would indeed be a nice feature for those of us in colder climates.

Not sure how this could be executed since Scouts are coming with a heat pump standard. Adding this feature would require some interface between the standard heat pump and a traditional heater core or an entirely separate heating loop using only a traditional heater core. Also, I’m guessing the majority of Scout customers do not live in a climate where this feature would be needed very often if at all.

 

[Last_Fun-tier]

This would indeed be a nice feature for those of us in colder climates.

Not sure how this could be executed since Scouts are coming with a heat pump standard. Adding this feature would require some interface between the standard heat pump and a traditional heater core or an entirely separate heating loop using only a traditional heater core. Also, I’m guessing the majority of Scout customers do not live in a climate where this feature would be needed very often if at all.

You’re probably right, and that the numbers might not justify it as a standard addition with a harvester package. Just thinking out loud, an Arctic option with an add on heater, core, supply and return coolant lines, and making use of the existing blower motor and ducting/vents would be really cool to see. Similar to adding a block heater from the factory for cold climate vehicles.

Or if there was a simpler way to capture heat released from the harvester engine, coupled with the heat pump plumbing would be maybe more feasible.

I’m sure there are plenty of trade-off decisions for the production model that have to be made, and this may not be worth the cost, space, or weight penalty involved.

 

[DaveGunter]

You’re probably right, and that the numbers might not justify it as a standard addition with a harvester package. Just thinking out loud, an Arctic option with an add on heater, core, supply and return coolant lines, and making use of the existing blower motor and ducting/vents would be really cool to see. Similar to adding a block heater from the factory for cold climate vehicles.

Or if there was a simpler way to capture heat released from the harvester engine, coupled with the heat pump plumbing would be maybe more feasible.

I’m sure there are plenty of trade-off decisions for the production model that have to be made, and this may not be worth the cost, space, or weight penalty involved.

Arctic package would be cool, and maybe something EV companies should consider as the use case for EVs is so different in cold weather.

 

[bwdavis7]

These are good ideas, but for the sake of simplicity and cost, I would prefer that SM make it simple for a DIY'er or aftermarket company to provide solutions, at least for aux cabin heat. If the Scout were to have a "port" or blank flange in the floor, let's say a 6" diameter hole that went from inside to outside the cabin, this could provide various options (not only for aux heat) for aftermarket companies to explore. This would be near zero cost for Scout production and simplify aftermarket solutions.

Apologize for repeating from a similar topic...but for aux heat this would allow two easy options. A package 2kw diesel heater (< $100) could be connected inside the cabin only needing 12VDC power (low battery drain) and an exhaust port (through the "port" mentioned above). These heaters can run up to 24 hours on less than a gallon of fuel. The second option would be to use the "port" as simply an opening to allow forced heated air into the cabin. This would be for stationary or camping mode only. The package heater would be outside the vehicle. Several companies like Vevor offer these self contained diesel heaters that you would only need to haul around to extend your mileage in extreme cold or extended camping in cold weather.

Being in South Carolina, the Scout would likely provide all my heating needs so my personal preference would be to keep it simple. However, if the need were to arise, I would like the option consider some temporary and simple aftermarket solutions.

 

[Crazychicken563]

Looking to revive an older thread as I had the exact same thought. Having the harvester running just to charge the batteries which would then immediately discharge that back into an electric heater just seems like such a waste. Battery heating for charging aside - just maintaining cabin temperature using the harvester would already by a huge plus.

I don't know what the cooling loop for harvester will actually look like, but surely the radiator will be near the front of the car which means a heater core could also be added for cabin climate... Unless I'm totally off base and the radiator for the harvester is entirely contained in the rear of the vehicle and they're doing some clever underbody areodynamics to get cold air back there for cooling.

We'll have to wait for more news to get specs and such, but just wanted to toss some more thoughts at this idea.

I also think the direction this thread took with arctic climates and winter temperatures feels a bit niche. There's plenty of reason to have heating in the car in other seasons - for example, if you go overlanding and camp in your scout in the spring / fall there is plenty of reason to want climate control running in the car overnight. Draining the batteries with an electric heater seems like it makes very poor use of the harvester.

The more integrated the harvester is with the functionality of the car - the better. It give so much flexibility to the entire package and it would be a shame to have it limited to an isolated range extender with zero additional benefit. If there's one thing ICE engines do exceptionally well - it's generating heat.

 

[Logan]

Looking to revive an older thread as I had the exact same thought. Having the harvester running just to charge the batteries which would then immediately discharge that back into an electric heater just seems like such a waste. Battery heating for charging aside - just maintaining cabin temperature using the harvester would already by a huge plus.

I don't know what the cooling loop for harvester will actually look like, but surely the radiator will be near the front of the car which means a heater core could also be added for cabin climate... Unless I'm totally off base and the radiator for the harvester is entirely contained in the rear of the vehicle and they're doing some clever underbody areodynamics to get cold air back there for cooling.

We'll have to wait for more news to get specs and such, but just wanted to toss some more thoughts at this idea.

I also think the direction this thread took with arctic climates and winter temperatures feels a bit niche. There's plenty of reason to have heating in the car in other seasons - for example, if you go overlanding and camp in your scout in the spring / fall there is plenty of reason to want climate control running in the car overnight. Draining the batteries with an electric heater seems like it makes very poor use of the harvester.

The more integrated the harvester is with the functionality of the car - the better. It give so much flexibility to the entire package and it would be a shame to have it limited to an isolated range extender with zero additional benefit. If there's one thing ICE engines do exceptionally well - it's generating heat.

If the harvester is in the back of the vehicle, I doubt that we'll see a front mounted radiator (those coolant lines would be loooooooong). Particularly given the frunk. But in the back they also have the spare tire to deal with (supposed to be underbody on the Terra at the least).

FWIW heat pumps are quite efficient at heating and cooling, way less power usage than resistive heating. But they also only work up until a certain temperature (generally not extremely cold. But that "extreme" cold seems to depend a lot on the model we're talking about. But sometimes its as warm as ~35f, and other times it can dip into the -5f range). And of course -40f is wayyy colder than that. So I doubt the heat pump is even in the discussion here. And resistive heating isn't very efficient.

All that said, I agree. I'd hope for harvester models, they would have a heat exchanger between the combustion engine coolant loop, and the battery/cabin warming loop. Otherwise that's a lot of wasted heat/energy.

I'd assume/hope that for sleeping in the vehicle while camping/etc, the normal use would be to use the heat pump if possible (ie, its still effective). If that doesn't work, it might fire up a backup resistive heater (ie, a "toaster"). And if that is insufficient for the heating needs (and/or the battery is too low and needs charging), then fire up the harvester and both charge the battery, and provide some heat (both to the cabin, and the battery if needed).

Another interesting idea might be to do cylinder deactivation when in camping/heating mode. IE, you might not need all the heat of all cylinders firing all the time. So running on 1-2 of them when in "heating/generating light load? mode might also get your fuel to last longer.

 

[Bertotti]

I'm holding out for the sodium ion adoption. Lighter and way more durable in cold cold climates. Much less expensive as well!

 

[Crazychicken563]

If the harvester is in the back of the vehicle, I doubt that we'll see a front mounted radiator (those coolant lines would be loooooooong). Particularly given the frunk. But in the back they also have the spare tire to deal with (supposed to be underbody on the Terra at the least).

Packaging will definitely be tough with everything they're trying to fit in there... Gas tank, engine, rear tire, and a useable truck bed all while maintaining sufficient ground clearance. That's why I assumed the radiator would be near the front, even with longer cooling lines.

You're likely correct about packaging - but also I thought the heat pump was not confirmed?

I mainly want to avoid the issues I have with my current 2021 Polestar 2. No heat pump and so range drops like 40% in the winter.. and that's before I crank the resistive heater. Mine you, I live in Ohio where the winters have not even been that harsh recently.

Since the harvester needs to be run once in a while anyway to maintain lubrication, clear out gas from the tank so it doesn't go bad, etc, I'd really like to see benefits from doing so.

 

[Logan]

I'm holding out for the sodium ion adoption. Lighter and way more durable in cold cold climates. Much less expensive as well!

AFAIK, sodium ion batteries are 20-30% heavier than LFP batteries for the same energy storage capacity.

And LFP batteries are also heavier than NMC batteries.

The harvester is confirmed to be using LFP batteries (they handle charging to 100% every day better than NMC, great for the smaller range harvester). And they have confirmed NMC for the Battery version. (More energy dense means less space/weight used by the battery).

 

[SpaceEVDriver]

There’s a virtual certainty there will be at least one heat pump for managing the battery and motor thermal environment; there’s no other way to do that efficiently.

There’s a pretty high likelihood that there will also be another heat pump for cabin environment control. Resistive heating is great when it’s directly applied (seats, steering wheel, etc), but it's pretty poor when applied as a radiative element. It won’t make sense to use a single heat pump for both the battery thermal management and the cabin environmental controls.

To manage the Harvester thermal environment (mostly to cool the engine, but it should also be able to warm the engine on a cold start), it makes sense to loop in the Harvester coolant to the cabin or battery thermal management subsystem. Personally, I’d loop it into the cabin environmental controls because I would want to have as little extra load on the battery thermal management system as possible. And because I would want to use the waste heat from the engine to warm the cabin in cold climates.

Both the cabin and battery thermal management will have an air-source heat exchanger (radiator) as the primary method for pulling or dumping heat to the ambient environment. The radiator(s) will likely be under the frunk. The current face of the vehicle is likely, IMO, to be more open for airflow than it is in the concept vehicles, at least for the Harvester.

Relatively new technologies such as vapor injection and internal heat exchangers have brought the usefulness of heat pumps for heating to -30 ºC ambient. You can get lower with other tricks, but the COP stats to approach 1.0, and in some cases can drop below 1.0, which means a resistive heater would more efficient.

I would much prefer to camp in a silent BEV than with a Harvester. The heating/cooling needs while camping aren’t all that high, especially with a couple of layers. I’ve seen less than a 0.7% battery use per hour for heating and even less with AC.

 

[J Alynn]

If the harvester is in the back of the vehicle, I doubt that we'll see a front mounted radiator (those coolant lines would be loooooooong). Particularly given the frunk. But in the back they also have the spare tire to deal with (supposed to be underbody on the Terra at the least).

FWIW heat pumps are quite efficient at heating and cooling, way less power usage than resistive heating. But they also only work up until a certain temperature (generally not extremely cold. But that "extreme" cold seems to depend a lot on the model we're talking about. But sometimes its as warm as ~35f, and other times it can dip into the -5f range). And of course -40f is wayyy colder than that. So I doubt the heat pump is even in the discussion here. And resistive heating isn't very efficient.

All that said, I agree. I'd hope for harvester models, they would have a heat exchanger between the combustion engine coolant loop, and the battery/cabin warming loop. Otherwise that's a lot of wasted heat/energy.

I'd assume/hope that for sleeping in the vehicle while camping/etc, the normal use would be to use the heat pump if possible (ie, its still effective). If that doesn't work, it might fire up a backup resistive heater (ie, a "toaster"). And if that is insufficient for the heating needs (and/or the battery is too low and needs charging), then fire up the harvester and both charge the battery, and provide some heat (both to the cabin, and the battery if needed).

Another interesting idea might be to do cylinder deactivation when in camping/heating mode. IE, you might not need all the heat of all cylinders firing all the time. So running on 1-2 of them when in "heating/generating light load? mode might also get your fuel to last longer.

I recall Scott K stating they have a creative cooling solution so I suspect whatever it is it will be a new approach so maybe there will be possibilities