I use the fan speed to adjust the temp when set to manual/recur <LO>. I would say the cabin temp is 70 to 72F. The older Model 3 cars with the PTS heaters used power while in AC Auto mode. The heat pump version probably works better, I will report back in a few months after I get my SMT up and running on the new rig. I have NEVER tried to get the cabin temp down to 60F.
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2023 M3 air conditioner using 70% of energy
Setting it to "LO" is telling the car to make it as cold as possible. (Some aftermarket companies use the Model 3 AC system to make a refrigerated van, so it is capable of maintaining a very large space at under 40F.)
It is possible that newer firmware versions don't throttle down the compressor as much based on fan speed, since that obviously doesn't achieve what is being asked for. (I know if I set the temperature to "LO" and it only got the cabin down to 72F I would say that it is failing hard.)
But really if you want it to be 70-72 why would you set it to "LO"?
It seems that this is continuing to be very difficult and confusing to figure out and analyze and solve because of this very factor of doing something that almost no one else does--using LO. I tend to be a very hot-natured person and like my car to be like an icebox when I drive, but that means I use a temperature setting of about 66 or something in the car. I think many of us would still really like to see some information on how it looks when using an actual temperature setting like that.
Also, the 9 mile super short trip thing was hard to learn anything from. Sure, I've seen over 1,000 wh / mile on short drives. That doesn't show if the HVAC will ever be able to settle down or not.
Also, the 9 mile super short trip thing was hard to learn anything from. Sure, I've seen over 1,000 wh / mile on short drives. That doesn't show if the HVAC will ever be able to settle down or not.
Given my 2019 A/B testing on our 2018 Model 3, as describe in my posts above, less energy was used with the <LO> fan speed method. Not saying this would be the same on the newer heat pump equipped models. The older models appeared to use the PTS heater to help maintain the Auto set temp. I am guessing this was done to dry the conditioned air (which should not be required with outside ambient temps north of 80F and humidity below 25%). The few times I travel to areas with very high humidity, I did sometimes run the AC in Auto mode with a set temp.
stopcrazypp
Well-Known Member
He's referring to reports of older PTC cars that still run the PTC heater even when cabin temps are 70. This adds up to around 1-2kW of draw. Using LO and the fan speed to throttle the compressor output eliminates that possibility. The heat pump cars however may operate differently.
I will say however when I do fan only, I do set the temp to LO, even in my heat pump car. This is because I'm in a mild environment where a setting of 70 can easily have the car start up heat (was true in my ICE car also). I've commented a bunch of times that I wish Tesla would follow the home AC convention where it is possible to turn off heat completely without needing to dial temps to the absolute coldest, instead of car convention where it is not.
Got it, so using a work-around intended to reduce energy usage on an entirely different system, is probably causing excessively more usage in the new system.
You may be absolutely correct. Even though the new heat pump model cars do not have PTS heaters, it could be possible AUTO switches back and forth between cooling and heating modes instead of ONLY cooling mode? I am not sure if SMT would be able to detect when the heat pump is cooling versus heating? Maybe there would be a power draw difference/change between heating and cooling modes? I am not loosing any sleep over this but just curious what happens behind the curtain when using Auto/Set Temp in both summer and winter months.
BTW, Thanks for the replies!
My understanding is that the heat pump system can heat and cool at the same time. No need to switch back and forth. (For example, in the winter it can provide heat and dehumidification at the same time.)
It would have to be able to show the mode the Octovalve is operating in. (Is it routing refrigerant to both the evaporator and condenser in the cabin at the same time?)
I don't see how that would even be possible. The way one of these creates the temperature change is by forcing fluid into a more compressed piping volume, which heats it up, or into a more expanded volume, cooling it off. I would be really curious how it could pump the fluid in opposite directions at the same time.
It has both an evaporator and condenser in the cabin, so it can route it to one or the other, or both.
Here is a video that shows how it works:
The in-cabin condenser is split such that it can be used for just the driver or passenger side. (And uses a expansion valve for each side so that a different amount of refrigerant/heat can go to each side to get different temperatures.)
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stopcrazypp
Well-Known Member
Long story short, along with the cabin evaporator all ACs have, there is a separate cabin condenser used for heat. If you look up pictures of the system taken out of the car, this becomes very clear (they are stacked right next to each other). This allows both to be on at the same time (necessary for things like defogging, where you need both heat and dehumidification at same time). It is not like most heat pumps where there is a single heat exchanger that serves dual roles with a valve to switch between the two functions.
This article does a deep dive based on patents. The details might be different from the production version, but the general idea should be the same.
How Tesla Heat Pump Works (vs HVAC Heat Pumps)
Tesla developed some of the most advanced technologies in the market including the heat pump...
aircondlounge.com
Service mode provides all the proper views to be able to tell which position the octovalve is in and how the coolant and heat pump system is operating.
There are numerous modes within the TMS. Dont think of it as heating and cooling. Think of it as, where is the heat transfer occuring and where is the heat being sinked to.
Pretty much the whole premise of the thread from the OP at the beginning is:
"I have a need to run my AC at max settings during the summer when I drive. Dont talk to me about any other settings. I dont understand why running the AC at full blast / max settings constantly is using so much of my range. Dont tell me to turn it to a number, I dont want to hear that".
When it actually does have significant impact on this question, since there is a difference in running the AC full bore at all times, and not.
I was in accident, just got a M3 LR. I was at max capacity 362 miles. After I got the car back I noticed about a week in it was sitting at 345 miles. In the Winter when I bought the car. 2023 AWD LR it was getting between 280-300+ miles per charge (in the winter). After accident I saw max range decrease to 345 miles and for some reason I am burning 300 KW/H going speed limit or roughly, towards the top half of the charge. Yesterday coming home after a brief stop at a charging station, I was getting 217 kw/h, but the battery was at 25%...Did not use maps, honestly just from memory (do we really remember how long we drive unless clocking it). Phoenix is just a widely spreadout open city, unlike most cities travel speeds are 50mph and usually only one or 2 red lights per mile at worst. So going 9 miles takes very little time. However, I found an interesting article from 2020 while searching google all this about tesla air-conditioner power usage - too bad I find nothing like this from tesla.
This article conflicts with what the service center told me that the AC was single stage, this tech says it is variable speed, which means the temp setting is going more greatly impact the power used. A single stage is just on or off and always draws the "about" same power. Variable speeds do better with less demand.Case for Tesla Pilot Mode: Tesla Model 3 Energy Efficiency & Use of HVAC
How do we find out how we are doing in any endeavor in a complex machine? The need is for specific performance data that allows an informed decision — at least, if we wish.cleantechnica.com
some other blogs...
Energy usage of the AC in very hot cliemate
I did some tests today measuring the power & energy of the AC in very high temperatures. It was 106 / 41 today in Northridge, CA. It used a little over 1 kW to keep the car cool. Here is a short video about it. I also did some testing driving. While I didn't include that in the video, the energy...teslamotorsclub.com
None of these are anywhere close to my range problem. thy are talking :Battery performance with air conditioner
Curious as new Y model owner. I’ll be living in Florida next year. I was curious to know what’s the battery performance like when you’re consistently running your air conditioner? How long does the buttery last, and how often do you need to charge?
"How much power does a Tesla AC compressor draw?
The compressor's power use can be only ~1 kW at low speed (4 range miles lost per hour) against up to 6 kW (24 lost miles of range per hour) with the compressor running very hard at full fan and at high compressor speed." My losses are much much more than those figures.
I will post more long range stats from my car with wh/mi etc..- hopefully tomorrow.
In winter 270-310 miles depending factors.
In summer after collision I am getting about 240-250 miles with much better weather.
I was averaging around 250-260 kw/h.. I noticed lately right after I leave a charging station I am using 300+ Kw/h being a slow good driver.
Its all wierd. I am taking it into the SC for a ticking sound in the front end, residue of accident but I am not sure WTF is going on. Its got 18K miles, not doing alot of fast driving. Most likely accident related.
Any thoughts?
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After reading this thread maybe its the AC unit. I have kept mine circulating warm air, although it doesnt explain why its using higher KW/H after I am done charging it at lower battery %, especially after its all cooled off. I will give the AC unit thing a try.
It was the AC unit consuming high energy. I turned off the open air vent to a closed air vent, and it fixed the high energy consumption. Got about 290 miles today on 90% charge. With AC on closed. Case closed.
Except for the 5% over night drop off. From 362 to 345 over night after accident. Still going to SC.
That was all high way too, which is even more impressive.
So we're currently on a quick road trip from Chandler to Pinetop and the energy consumption is off the charts. I've done this trip a few times in this Y and the range calculator has always been pretty accurate (and closely matched ABRP), but today it was wildly off.
Leaving from Chandler at 100% charge to the Payson supercharger, it said I should arrive with 50% and I arrived with 39%. I've never used that much energy doing this drive. Note: ABRP calculates arriving at 46% when leaving with 100% and is closer to what I usually arrive with.
Then while charging, it was showing a much lower arrival battery % to my final destination in Pinetop than I'm accustomed to, so I had to charge longer to make sure I would make it.
When finally leaving the supercharger at 94%, it said I should arrive with 37% and then jumped to 50% when I started driving. It then slowly adjusted back down to arriving at 37% during the drive. Note: ABRP calculates arriving at 43% when leaving with 94%. Not as big of a difference, but still pretty far off.
You might be on to something here. My AC never seemed like it got to an efficient state, constantly blowing the fan at high speeds. If it was never in recirculation mode, it would be trying to cool a cabin down to 70° while sucking in 100° air. I'll try manually going into recirc mode on my trip home tomorrow and see if it changes anything.
We drove home today from Pinetop to Chandler via Globe. We left at about 92% charge and the Tesla initially said we should arrive with something around 40% without stopping for charging.
As soon as we started driving, the estimated arrival % started dropping 1% every mile or so. It finally settled around 23% for awhile. We ended up getting home with 17%.
I drove very gingerly once I saw the % dropping, as I was afraid I wouldn't make it home because there aren't any superchargers along my route. I accelerated very slowly, drove the speed limit, and tried to stay under 65 as much as possible. I even turned my AC to 72, low fan, and recirc on. It was over 100 degrees during a large part of the drive.
I've attached the energy graphs to see if anyone sees anything out of the ordinary.
Some notes/questions:
1) Did Tesla change the algorithm for calculating estimated energy usage? It seems like it's calculating estimated energy based on ideal conditions instead of using the actual conditions (which I thought it used previously). It knows the speed limits (knows how fast I'll be driving), knows the elevation changes (so should know usage based on uphill and downhill driving), knows the weather and my current AC setting (so should know climate system usage), and knows my previous driving habits. It displays the wind affecting my range on one of the screens, so why doesn't it calculate that in the beginning instead of showing it as a delta at the end?
2) This can be a dangerous problem if you start out a trip assuming you can make it but get in the middle of nowhere when your range starts dropping rapidly. In the almost 3 years I've owned this Y, I've never had the estimated range be this far off. I'm not a new owner with range anxiety/shock. I'm driving the same vehicle on the same drives and it's suddenly changed. Something's not right. I used to be able to trust what my arrival % would be, now I have no idea.
Gauss Guzzler
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