-
Skin cooling system info
-
Skin cooling system info
updated 1 week, 6 days ago
46 Members
·
81
Replies
-
@David Pastorek – The belly of the Aptera is an aluminum heat sink. See the red circle, below.
As @Tim Dean said, the upper surfaces of all Apteras will be either black, solar panels or glass.
Aptera vehicles are air conditioned and heated so the cabin temperature is adjustable.
When parked in the sun on a hot day the basic solar package will power the flow-through ventilation system to keep the interior of the vehicle at the ambient temperature: No more climbing into a 120° car on a 90° day!
The battery pack is inside the body shell and is, therefore, somewhat insulated from exterior temperatures. I’m sure, like all EVs, if the pack temperature starts to rise the vehicle will automatically attempt to cool it.
-
My 2021 M3 can lose as much as 30 miles in a few hours of trying to cool the interior. This is on a 98* day while the setting is on HIGH temp of cooling the interior. That’s above 80* on the inside. Venting the windows doesn’t help.
Solar panels get hot. Since venting the Aptera’s windows will only release heat from the mid point of the interior it would seem lots of heat would get trapped inside from the mid-arm upwards. Do we leave to leave the hatch cracked open when parked? I suspect that with the gull wing doors most of the heat would be released once you open the door. Is there a way to leave the door windows down and not have anyone get into your car?
How much range is lost in the 8 hour day while at work? Will the solar charging compensate for it and what solar package is needed to accomplish this in order to have a gain at the end of the day?
-
This reply was modified 1 year, 10 months ago by Steven G. Bueche.
-
The plan is for the vehicle to circulate interior/exterior air without using cooling power (Basically powered venting), to allow the cabin to remain at the outside air temperature and avoid the typical vehicle heating from direct sunlight. (The cause for excessive heat in a parked car.) This will be far less power sapping then trying to cool the trapped air, which is what standard A/C entails. This plus the insulation provided by the thick composite walls, should make for a very efficient system.
-
This reply was modified 1 year, 10 months ago by OZ (It's OZ, Just OZ).
-
This reply was modified 1 year, 10 months ago by
-
This reply was modified 1 year, 10 months ago by
-
I Hope the Aptera engineers are designing the HVAC system to maintain the cabin temp at 70 deg F when 2 people are either parked on asphalt with no air movement across the belly pan when in 120 deg F sun or during a -20 deg F snow storm.
The Aptera HVAC system needs this capability for traffic accidents, camping & a roadside snooze for as long as the batteries maintain power.
-
Having owned two 1950’s vintage British cars, I am familiar with inadequate cooling when caught in slow traffic. One of the advantages on an EV is that the batteries only heat while being used. My question is, what will cool the battery packs when the car is sitting in a stalled traffic jam in 100F heat and running the heat pump?
-
Aptera doesn’t have a heat pump but maybe you mean the air conditioner. There is no official statement i can remember regarding how it will dissipate heat. My guess is the a/c system will be separate from the battery and use its own fan to pull air thru the gaps in the front suspension.
For the battery, the plan is to use a large metal heatsink located on the belly to keep the battery at ambient. This will work perfectly fine sitting in traffic due to the car not generating any heat.
-
I’m bored so I’ll contribute to the idle conjecture. In a recent (June 2022) video from Aptera Owners Club showed a photo of the new redesigned motor from Elaphe. It was strikingly different from previous photos in that it showed hollow gaps where metal had previously existed plus it did NOT show any tubing or connections for motor cooling. Also keep in mind that the base Elaphe motor model is/was their M700 (for 70 HP) which Aptera is detuning down to 50 HP. So it very well could be that the production Apteras will use air cooling for the motors. So an Aptera idling in Phoenix in summer won’t need much cooling for the batteries since the Aptera is barely moving. The outboard front wheels would benefit from increased airflow available to them.
-
@BRUCE MENGLER Remember, it’s only a rendering – that also doesn’t show brake lines or any of the other cabling shown in images of the Beta motor. Aptera is not going to switch from a liquid-cooled to an air-cooled motor.
-
-
-
I’m also concerned about the color of the car having a negative impact on the skin cooling technology, personally I would love a black car, but my preference is function and efficiency over form so I’d love some clarification on whether a black car has a negative impact on the cooling, as well as if it has a positive impact on solar charging.
-
As I understand it, “Skin cooling” is only on the belly pan under the batteries. I doubt that area is even covered by the wrap. The Aptera is all about K.I.S.S. Heck, even the wiring harness is designed for simplicity & lightweight. Truly a ground-up redesign of transportation.
-
Black is a better radiator than white. A black belly pan and a white body would give you the best result. Add 3M radiative cooling film to the solar panels and you will get more power due to the lower temperature. No point adding the 3M film to the belly because it does not face the sky.
Look up https://www.3m.com/3M/en_US/energy-conservation-us/applications/passive-radiative-cooling/
-
This reply was modified 1 year, 9 months ago by Llewellyn Evans.
-
This reply was modified 1 year, 9 months ago by
-
-
Info from a reliable source indicates the aluminum belly pan will be black
-
I have read in different discussions that battery cooling will not be active when the Aptera is not moving. That is disturbing. I live in Deming NM and my driveway is concrete. Will it be better to park my Aptera on sod or dirt in the summer when I’m sun-charging it?
-
This reply was modified 1 year, 8 months ago by Lane Costilow.
-
Parking in a kiddy pool so the belly pan is in water may be your answer! Seriously, a lot of us have had questions about stationary cooling via the belly pan. The answer is that no one knows. This is an area we have not received much information about from Aptera.
-
This reply was modified 1 year, 8 months ago by
-
In case you missed it mentioned in another thread, an Aptera engineer did a live stream at the Fully Charged event a few days ago and answered tons of questions, including one on the cooling system. He revealed that there will be a radiator inside the vehicle to help with cooling loads when the skin cooling through the belly pan can’t meet the cooling demand, particularly at low speeds.
Here’s the full quote:
“Skin cooling is awesome for high speeds — not awesome for low speeds. Skin cooling is incredible at high speeds, you don’t need a radiator. At low speeds we actually do suck air in from the outside of the vehicle through holes like this (points at the bottom of the windshield) and we have a low-speed radiator specifically for this so that the vehicle can’t overheat when it’s parked or anything. And it’s gonna vent right out here (points at the back of the vehicle, next to the license plate holder). These are vents for the secondary radiator.”It’s in this video right at the 9 minute mark: https://youtu.be/xvdmVFu4HgE?t=540
I was super relieved to learn this, since I was pretty certain that skin cooling via the belly pan would not be sufficient by itself, and I wasn’t sure if they would have enough free space inside the belly of the vehicle to package an extra radiator and associated components. But I’m still looking forward to learning more about the nitty-gritty details of how the whole cooling system integrates together.
-
Does having a radiator necessarily mean that it will need to be maintained – periodic top off, periodic fluid flush, hose replacements, etc.?
-
@Jeffrey May – The young man in the video you posted isn’t an engineer – he’s a member of the marketing team. The video below features the engineer responsible for the wheel pants but he explains (at 10:12) how Aptera will use the air conditioning radiator and ventilation exhaust to cool the battery during charging. https://youtu.be/vI7kegmY6e8
-
Here’s the interview with the engineer for the battery cooling.
-
-
-
Are there still micro channels present in the CPC BinC bodyshell involved in skin cooling? If not, this could be one reason why DCFC is MIA on the LE.
-
The skin cooling is done via the belly pan. It is made of aluminum, because aluminum conducts heat better than composite.
-
That was my original question thread earlier. Whatever happened to the much discussed before “micro channels” involved in skin cooling? I think it disappeared, once the solid BinC composites were considered. The curved aluminum belly pan is insufficient for any adequate battery cooling for DCFC (obviously finless, for aerodynamics).
Aptera is radiator-less afaik. I hope I am wrong, but I am afraid to say…DCFC will never happen (unless there is a true radiator retrofit for DCFC battery cooling), at the very least. I hope CA wasn’t serious (no gaslighting) when he said that the Aptera does not need DCFC.
-
The micro channels were never going to be in the composite body, only in the belly pan. The early video was unfortunately poorly executed.
-
-
Can vertical cooling fins be added to the top side of the aluminum belly pan? (This would be in the interior of the vehicle.) Then additional air blown over these fins and out the back for additional cooling.
-
The more power you draw to the batterys for charging, the more cooling you need. Very sad that aptera always mentioned a slowish 50kwh charging solution, and now does not even offer 20kwh. 6.6kwh is the max……
-
The core of Aptera’s design advantage is aerodynamic efficiency. A traditional radiator would destroy that. That is why skin cooling is sacred.
I am confident, though not certain, that Aptera will find a way to make it work. The missing link for now, maybe, is a heat pump that can be integrated into the cooling system somehow.
Aptera has assured us that all Apterae will be upgradable to DCFC when they work it out.
-
Did anyone watch the Gamma not get up a hill on a tv interview? That looked like a serious cooling problem to me.
I like to be able to drive up a hill whenever I need to its kind of a big deal.
Think we all need a bit more assurity our vehicles dont or wont overheat
-
@paul-newton Things to remember: Gamma is a hand-built design prototype, not a fully-functional vehicle. Gamma does NOT have a production battery pack. Gamma’s battery pack. Gamma does not have a belly-cooling radiator so its motors, power electronics and battery are all trying to use a tiny radiator that is NOT exposed to outside airflow. Remember the little radiator on the front of Beta? That’s pretty much what Gamma has…
-
Thanks mate – jeez then why the hell are they touring it then? Seems a very risky thing to do with some spectacularly bad publicity potential just waiting to happen. Lucky it hasn’t had a thermal runaway event…
Cant wait to see the solution tested and working robustly and breezing up the tallest hills, as Ive got a few I need to drive through when I get mine.
-
-
-
This reminds me of the wobbly wheel pants with Jay Leno. If something is not ready for prime time don’t put it on and make excuses for it. Instead of searching for a billionaire maybe time should have been spent upgrading the Gamma. I do not believe this Gamma even had the new motors, which are not as powerful. What would have happened with them? If this whole review had started out with ‘ this is still a prototype’ it would not have been as bad. Makes Aptera look like a Moped.
-
I’ve voiced the concern that people should withhold calling this vehicle a “sports car” because of how little information is available about its cooling system currently. One of the issues with Aptera’s enclosed wheel design, at least from a performance perspective, is the thermal management double whammie of have two major sources of waste heat generation, hub motors and and brakes, in close proximity and being enclosed. Day to day it might not be that much of a problem with regen braking but once you start pushing the limit and using the actual brakes you’ll be generating massive amounts of waste heat that will need to be extracted from those enclosed spaces through the cooling attached to the hub motors. Can Aptera’s supposed belly pan system handle that? Is the belly pan cooling idea still even being worked on? Questions to be answered, though the fact that there is little to no information about it is concerning.
-
The “belly pan” remains the ultimate liquid-to-outside-air heat transfer surface of the real design. NONE of the prototype vehicles have had that installed. They have all had little “traditional” radiators somewhere. The surface area available for the belly is quite large, compared to radiators. I also have faith that the liquid circuits for load (battery/inverter/motors and AC) to sink (belly pan) is reasonably straightforward and being done with adequate margin. Could they have included such a system for a demonstration prototype system? Sure. SHOULD they have? In hindsight, probably. But a flat-plate heat exchanger, which they DID prototype, really is not rocket science, nor are liquid cooling paths and systems.
-
-
I wonder if Aptera will use battery coolants like LiquiMoly EV200? Supposedly these (and other fluids like brake & gear oil) are designed to help dissipate heat in EV use. It will be interesting to see what Aptera recommends.
-
At one time Aptera indicated the use of plain old propylene glycol for the cooling system. I would not use this kind of advertised product until it has gone threw some third party testing to validate some significant benefit over the current fluids. Could be charging more for no significant benefit. Not that anyone would try to capitalize on EV owners……
-
A bit more info about the system in Steve’s latest video:
Aptera’s belly cooling patents shed some light and bring up some questions – YouTube
-
A patent application for the system.
-
Thanks for sharing that! They’ve been talking about using a heat exchanger instead of the belly pan for cooling recently, hope this indicates that they are much further along in the development of belly pan cooling.
-
The design is done but don’t have the capital to implement it, hence the cheaper/easier heat exchanger.
-
The short-cut to implement a traditional radiator is a real drag. Literally. In my view, it is a mistake because design will be tricky. They are going to select an off-the-shelf unit and may err on either the side of too big, and too much drag, or too small, and we all know where that heads. This efficiency loss, along with avoiding silicon inverters, is signs of chipping away at the efficiency-first mantra. I fear they have failed to prioritize top-notch engineering. Concepts, OK, but the devil is in the details. (I can’t believe I used that old saw.)
-
-
The car that over heated was not hooked up to any thing just filled with coolant and cap. The under panel should be all the cooling the motors need for most conditions. And my guess is that the others are A.C. And heat pump. I am so happy they went with aluminum for the under belly cooling. I have had some experience with composite panel’s for heating and cooling we went with aluminum much easier to connect to. Better heat transfer. More durable. Far less charge of leaking. I would not worry about over heating unless you’re where it’s over 110 f but then every thing over heats at that temperature. You might have to slow down or stop and let it cool down just like a I.C.E. (No worries)
-
I hope the skin cooling system is active and functioning by the time I take delivery.
Difficult to hear more details but I got that there’s three cooling circuits;
1. Inverters and Motors
2. Batteries
3. HVAC
-
If I can remember they are going to use a forced air method plus a regular radiator in the front. They are going to pull in air where the windshield wipers and force it through a radiator and then along the top of the battery then out the back on each side of the license plate. I believe they will use the forced air when you use the ac or the car is needing extra cooling from a extremely hot day or your pushing the car which heats the battery and motors more than normal. I think the skin” cooling will handle everything when its a nice day out and your driving normal, don’t think enough heat will be created to need forced air. But once temps start to get to high that forced air will be able to handle whatever your putting it through and if it cant keep up it should just do what every other EV does and limit how much power you can use or are able to charge at. I suspect they will make the cooling strong enough to handle 50kw fast charge speeds on a hot day and if its extremely hot they might need to throttle it back to 30-40kw speeds. Skin cooling should handle everything till it cant and the forced air needs to take over.
-
Here, at about 5:20, sounds like “base” in his question is referring to belly cooling and Chris’ answer makes me think skin cooling, those channels, are not there, currently or maybe I’m just breathing into this more than I should.
.
https://m.youtube.com/watch?t=320&v=utgdsvm8tAo&feature=youtu.be
-
-
-
Another related patent application:
