[Chickster]

In my 2020 e-Niro the lowest temperature you can set is 17 degrees. Does anyone else think this is not low enough? Previous car was 16 and other car which is a Honda goes to 15 degrees.
Maybe there's a reason in an EV? Would use up too much battery to cool so low?

 

[Gif]

I think most cars when switched to the minimum setting just run the air con pretty much full on constant anyway. What you want is called a fridge

 

[EV Adopter]

In my 2020 e-Niro the lowest temperature you can set is 17 degrees. Does anyone else think this is not low enough? Previous car was 16 and other car which is a Honda goes to 15 degrees.
Maybe there's a reason in an EV? Would use up too much battery to cool so low?

I cant see why you would want it anything like that low. I find 21deg is perfectly could enough. What is more important is the quantity of heat that can be removed to get down to a comfortable temperature..

 

[graememk]

I cant see why you would want it anything like that low. I find 21deg is perfectly could enough. What is more important is the quantity of heat that can be removed to get down to a comfortable temperature..

Some people just prefer colder temperatures, I usually don't have it above 18 or 19 even in the winter.

That being said, there is no "low" setting like we had in our Sportage, which would have icicles hanging from your nose! We have found that getting into the car after it sitting out in the sun all day, it can take a while to cool down.

Thankfully precooling from the uvo app is an option now and that usually does the trick

 

[80698]

Just to be clear. Are you unhappy with the temperature of the air coming out the vents? Or are you unhappy just becase the number is one degree warmer than you used to be able to set?

As has been said, when you have the AC running at a temperature lower than it currently is, the compressor will be running as full power and blowing out the coldest air it can possibly manage to bring it down to, and maintain the selected temperature. After a short while of running, with the fans brlowing directly at you it should still feel very cold and comfortable even on a hot sunny day.

(As a side note, the lowest temperature I can select on my home air conditioning is 18. I have absolutely no problems with that and have even found it to be too cold at times)

 

[Gdank]

In my 2020 e-Niro the lowest temperature you can set is 17 degrees.

It probably means once you set it to 17 deg the aircon is already running at max. Any lower it will just pull outside air in as that would need to be lower than 16deg.

My Kia only goes down to 16deg, then beyond that it's "LOW" ... there is no difference between it at LOW, 16, 17, or 18deg ... the fans and AC is running at MAX power - assuming outside air is around 24deg.

 

[Ian]

Is it 17°C minimum with the car mode set to Eco, Normal or Sport? You can change the air-con effectiveness In the setup.

 

[Chickster]

I just like it cold but on a lower fan speed setting rather than warmer but trying to make it cooler by having fan on higher speeds.
There has to be a difference between low, 16, 17 and 18 otherwise manufacturer would have lowest setting as 18.
I haven't tried to see if the lowest setting is different in the drive modes, I'll try.
Thanks

 

[Ritzspark]

But it doesn't make the air coming out of the vents any cooler, just the end temperature.

 

[80698]

But it doesn't make the air coming out of the vents any cooler, just the end temperature.

This.

So many people don't seem to understand that thermostats, be that for air conditioners or heating in their homes and cars are simply an on/off switch for hot/cold depending on the current temperature. Setting it to the highest or lowest setting doesn't make the temperature change any faster or slower. It just gives it a target temperature to aim for before it stops heating or cooling further.

OP - You're getting too worried about the numbers and not the effectiveness of it. If you set it to 17 you will still feel nice and cold just like you would in any other car.

 

[Gif]

Setting the temperature lower doesn’t make the air con unit any colder but it does increase the circulation of air as the fan speeds are temperature differential dependant if that’s a phrase. So the greater the difference between the internal temp and the setting on the control, the harder the fans will work to try to rectify the difference (in Auto mode of course!)

 

[Greg Elmassian]

home air conditioners are an on-off compressor switch... true.

In cars, the system modulates the temperature with normally an air mixer valve, and also modulates the compressor on and off to maintain temps.

Car systems are one of the few HVAC systems that are not either full on or full off (not counting fans)

So the systems are indeed different. At the extreme low point, depending on the ambient, the system is most likely on as much as it can be, within the limits of pressure (protects itself from icing)

Greg

 

[DragonQ]

home air conditioners are an on-off compressor switch... true.

In cars, the system modulates the temperature with normally an air mixer valve, and also modulates the compressor on and off to maintain temps.

Car systems are one of the few HVAC systems that are not either full on or full off (not counting fans)

So the systems are indeed different. At the extreme low point, depending on the ambient, the system is most likely on as much as it can be, within the limits of pressure (protects itself from icing)

Greg

I'm not sure about the US where there are far more older units around, but modern A/C systems for buildings are almost all inverter units in Europe. It might even be forced by EU regulation since they are generally more efficient and quieter (and better at keeping a steady temperature), not sure.

 

[Greg Elmassian]

Yes, you are correct, newer units do have effectively variable compressor speeds, and the inverter is the electronics that allows this.

Was keeping more to the "norm" in the US, and also more focusing on the variable systems in cars.

Very few home and business installations have this, most are old school. More people in the US are adopting the "mini split" systems popular in other countries, I first saw these in Japan years ago.

Greg

 

[Phevourite]

In my 2020 e-Niro the lowest temperature you can set is 17 degrees. Does anyone else think this is not low enough? Previous car was 16 and other car which is a Honda goes to 15 degrees.
Maybe there's a reason in an EV? Would use up too much battery to cool so low?

I had exactly that thought for a moment. I changed my mind.

Here's how I think it works. In normally-priced cars the aircon is in no way sufficient to actually cool the car. It is not a volume cooler like a fridge would be. The way it works, I think, is that the chilled, dried air has a cooling effect when it hits your skin. If you are not sat in the draft of the vents, you will feel little effect. Your Honda will not be able to cool the interior down to 15 - even if it claims that it can. Not on a warm day. While your fridge will only run its compressor occasionally, in your Honda it will run continuously and still never hit 15 measured say in the back seats on a hot day.

During the very hot days we had recently I noted that after a very long drive, when we stopped and took items out of the boot of our Kia e-Niro they were cool. I have never noticed that in an affordable car before. I believe this suggests that the AC is more able to chill the interior volume than many other cars. I still don't think it is an effective volume cooler, but I reckon that 18 degrees of chill in our Niro gets the car colder than 16 or 17 in other cars I have owned.

This might be, I think, because EVs have run their a/c from a motor at constant speed, not like the ICE which has to make it work over a wide range of engine revs.

 

[Greg Elmassian]

I don't know why you are trying to make up a new type of cooling.

Yes, of course air hitting your skin will have a cooling effect if you are perspiring...

With the system in recirc mode, it's just like a fridge EXCEPT that the fridge compressor is either full on or full off. The units in our cars can either vary the compressor, or use air mixing to control temperature, and I have not seen an authority on this yet as to exactly which modes our cars can do.

But all if this is moot if you are running the system in max cool, where the compressor is flat out.... I like the system in the car, it is good, but not as effective as my Fiat EV, but I suspect that this is from the smaller volume of the car and more upright windows and no sunroof.

Of course the internal temp is always affected by the outside temp in any HVAC system.

Greg

 

[Phevourite]

With the system in recirc mode, it's just like a fridge EXCEPT that the fridge compressor is either full on or full off.

No. Cars are not like fridges. This was my point. My fridge runs for a few hours per day. It maintains its target temperature (5 degrees C) within roughly a degree. I tested a midsize car a/c system thoroughly once. With an outside temperature of 28 degrees, it managed to cool the interior to just 27 on average by running continuously. The thermal loss hugely exceeded the the capacity of the compressor to cool. The differences are that my fridge is not outside in direct sunlight, does not have windows and has effective thermal insulation.

A car's a/c system cannot chill its volume on a warm day in the way that a fridge does. Under these circumstances, the numbers on the car's temperature control dial much below ambient are pointless.

Yes, of course air hitting your skin will have a cooling effect

Despite the a/c being ineffective at reducing the temperature of the car's internal volume, in hot weather it is more pleasant to sit in the flow of chilled air than to be in its path and not have the compressor running. When the thermal losses are great, then being directly in the flow of chilled air becomes the benefit of having the a/c on.

Yes, of course air hitting your skin will have a cooling effect if you are perspiring...

With the possible exception of Prince Andrew, all people perspire when their core temperature is raised.

I don't know why you are trying to make up a new type of cooling.

Why do you say this? I am not.

Of course the internal temp is always affected by the outside temp in any HVAC system.

No it isn't always affected. If the thermal loss from the enclosed space is significantly less than the cooling power of the system, then the internal temperature is determined by the control system. In this case the system will operate like a well-well-functioning fridge.

Only if the loss is significant does external temperature have an effect on the internal temperature. For cars, the losses are massive and so they do not work like fridges, at least in warm weather. For buildings, there is a range of operation. Many buildings have large thermal losses and so relatively inadequate a/c power of course, but by no means all.

 

[Greg Elmassian]

I said the cooling system was like a fridge, not a car is like a fridge.

I'm talking about how the system works, not it's btu capacity, nor the thermal loss of the "housing".

You are getting silly about your theories. I will stop arguing with you, and I challenge you to take your theories to an actual HVAC engineer.

By the way when you quoted me:

I don't know why you are trying to make up a new type of cooling. (greg)

You asked:

Why do you say this? I am not. (whoever you are)

Because you said this: Here's how I think it works. This is clearly you making a theory about how it works, and your statement:
The way it works, I think, is that the chilled, dried air has a cooling effect when it hits your skin.

Duh! of course cool air will chill what it is in contact with. One heckuva theory.

Just silliness... I'm not playing anymore... talk to an engineer, a physicist, or someone who understands HVAC systems, not just someone who repairs them.

Greg

 

[prawlin]

Whoa, steady here chaps please😉.

Just a few facts to throw in here fwiw. Both my Prius cars over 19 years had CC AC systems. The first was conventional crankshaft driven compressor and the last was an all electric HV 3 phase sealed compressor with fully variable modulated RPM speed (presumably ENiro is similar?) . The entire car (in both cases) could achieve the target temperature inside the cabin. Even if the outside was say 30°C, the cabin insides would reach say 20 or even 18°C No doubt about it. I have a separate thermometer always inside the car away from the cooling air vents.

In both cases, the AC cooling was way more powerful than the insulation losses. It naturally would take longer to achieve the target temperature but it would always get there sooner or later. The earlier car would start to pulse the magnetic clutch on off with the duty cycle reducing as the cabin nears the set target temperature. The later one would run the compressor continuously and then reduce both the compressor and the circulation fans RPM as it nears the target. When it achieve the target the compressor would cycle on off as needed to maintain the achieved temperature and to de ice the evaporator core.

IMHO, if a car with a proper CC system cannot cool the main volume of the car atmosphere fully to the target temperature then the AC system is either of poor design or (more likely) requires servicing or regassing.
I certainly hope my new E Niro (next month) can achieve the above, no matter how hot it is outside. If it can’t I will be somewhat disappointed and dismayed.

Not taking any sides here guys, just throwing in my twopence worth, from my engineering/scientific background standpoint. If anyone disputes any of this, let’s just agree to differ and move on.

cheers
Peter

 

[Gif]

Not taking any sides here guys, just throwing in my twopence worth, from my engineering/scientific background standpoint. If anyone disputes any of this, let’s just agree to differ and move on.

Not until everyone's waved their proverbial willy I'm afraid