Estimated EV penalties for various heating cooling and lights

Of course, it is highly dependent on the ambient temp. I would think the Heating and the Colling in the prime using the heat pump works at the same efficiency under identical conditions. After all, both are using the same components just in opposite directions. If it is 90F outside, you really can't heat the cabin using the heat pump. Likewise, if it is 20F outside, you can't cool the cabin using the AC.

 

That's what I would think too. But even though my heating needs are much less than cooling needs, heat puts a noticeably bigger dent in my EV range. I rarely use heat but sometimes, when I start out, the AC will be on Auto and set to a couple degrees higher than the cabin temperature from a warm day the day before. It'll be heating for a while until I notice that my battery level is dropping too fast. When it's cooling, even on a hot day, I don't see as much impact.

 

Not that I really know how the heat pumps work and the physics behind it, but I can see why you are seeing more EV dent on the heat side compared to the cool side in that situation. In reality, you are trying to extract heat from the very small cabin space to cool it down for cooling function. But for heating function, you are trying to extract heat from the vast space outside. In essence, the heat pump is trying to cool down the outside air.

I would think the ideal condition to test would be ambient temp at the middle of the operational range of the heat pump. Say if I assume it works from 14F to 100F, then somewhere around 57F. And test the current draw in heat and cool setting with all doors and hutch opened, and maybe even set up a few portable fans to exchange the cabin air to equilibrate the temperature with the outside. If you do that, my guess is that setting the temperature on HVAC to the lowest temp (high cool) and to the highest temp (high heat) would use a very similar amp draw.

That being said, I can see with the closed environment of the cabin, for the same temperature change, say raising the cabin temp 2F vs lowering the temp 2F, it may be true that heating always uses more energy than cooling.

 

It kinda makes sense when looking at it from the computers perspective. It takes time for the computers to adjust for efficiency from new inputs. If the car has similar data points most of the year, than those typical (user defaults) are well defined to the system and the system preforms as usual.

Making changes like going from 300 days of using A/C per year, to the 65 days of using heat per year, it takes the computers a while to readjust to the new data it gets 65 times a year. Most of us think that those adjustments should be immediate, much like we humans adjust to the changes we are used to on a daily bases.
ie: trying to imagine how many things the computers in the car are monitoring to make the car as efficient as possible - than try to imagine which ones need to be optimized when switching from A/C 300 days a year to heat 65 days a year. One obvious (kinda to me anyways from up here in the northern wastelands) is pack temps, at least from what I've seen during hot summer ambient temps that last more than a week and the length of time it takes to cool the pack that's been heat soaked above 100^ F.

 

One must also consider the "delta t" -- i.e., difference in temperature -- that the heat pump is trying to achieve. In the summer when it's 90F outside and you want the comfort of a 70F cabin, the difference is only 20 degrees. But in the winter, then it's 30F outside and you're satisfied with a cabin temperature 60F to be moderately comfortable, the difference is 30 degrees. So the heat pump is going to have to move 50% more heat into the cabin in winter than it has to remove in the summer.

There is no doubt that climate control is an energy intensive endeavor. Many people are not aware of how much energy is consumed by buildings (including houses) primarily for heating and cooling:



And, consider that buildings don't move around like cars and trucks!

 

It seems complicated but it's really not. A heat pump is a kind of refrigerator, or a freezer, or air conditioner. Energy compresses chemical refrigerant, & that creates heat during compression. Decompressing the refrigerant causes cool. Reverse the unit to use as heat and you have the system.

The only downside of a heat pump is when temperatures get down below freezing there's not much heat left to pump.

 

The other part of the equation besides the efficiency of the amount of fuel consumed for any particular process and which most of us are very familiar with, is the amount of waste produced by any particular process which is what most engineers are most concerned with, until it's time to explain the cost runs of any particular process to the bean counters.

@Old Bear agreed, but in real life - how many times when it's 90*F outside is it also 90*F inside the car?

 

When our well insulated garage is 90° (or 45° or 70°) & the car's windows are down? then yea that's the cabin temp too.
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and the temps of most other parts of the car that have had enough time to heat up or cool down.
Yeah, I see your point, it's nice to have a comfortable nest for the car when it's really hot or really cold outside.

 

Many of our neighbors have giant four-by-four diesel pickups. When the temps are 0 or below, they all have their engine blocks plugged in - sitting in their driveways - so they can start the darn things. Warm them up inside or outside .... pick your poison

 

I wonder how much power the main touchscreen display uses (11'' VS 7'')?

 

Me too !
But whatever the diff is, I'm just glad they are both LED screens and not CRT screens.

 

Can't be much. My 14" MacBook Pro with M1 Pro cpu only uses maybe 10 watts for the computer & the 14" screen unless I'm pushing it hard.

 

The traction pack coolant heater on our plug-in minivan can pull up to 7kW. Put your foot into it on a below freezing day? The ICE will do THE rest of the 5 - 10 minute warm-up for you (turning on how cold it is) - instead. Nothing wrong with burning a bit of gas when it's clearly the best way to go.
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Thanks for sharing such a great information