Electric airco on hybrid / side effects ?

[haelewyn]

Hi guys,

Was testing the airconditioner on my hybrid Auris at temperatures outside 30 degrees and switched to automatic inside about 21 or 22 degrees.

It seemed the HV battery was draining faster.. Could be normal as it is an electric system. That would mean it is not using fuel but drains the HV Battery extra when in use which would cause urban driving worse MPG.

I saw the ICE didnt switch off like usually but most of the time stayed on. Even when no throttle at 15 km per hour.

Could see 2 reasons for that.  The Battery is easier on low charge and so the ICE kicks in. Because heavy drainage the mimimum treshold for making the ICE run could be set on a higher percentage. Also thinking maybe the ICE will keep running more when the airco is needing power to cool the car.
Was driving in ECO but short trips which needed the airco to cool all the time. 
I saw the ICE only switched off at times when there was a high HV Battery charge.

Anybody can confirm by own experience ? Is it really using a lot of the HV battery charge ? Or can anybody give some extra theoretic information to confirm this ?

My idea or feeling was sometimes that the HV battery was not working properly but this car is less than 3 years old with low mileage so that would be unlikely.  Would still be under warranty anyway..  I am thinking the airco was just taking a big bite of electricity..Toyota gives some warnings, altough not very well explained.

[YarisHybrid2016]

It's because you set the temperature to 21/22 deg. C.

Counter-intuitively, it will run the engine to warm the coolant for the heater, even though the cabin is easily at this temperature.

I find it best to set the AC to LO, set the fan to minimum, and manually control the direction of the airflow.

This way, the engine won't run despite the temps, and you won't freeze yourself out!

Don't worry about ice formation on the window - this is normal!

[haelewyn]

Normal,  just as any aircon car losing a few drops of condense water while aircon is working..

Will check the settings in the way you advised.  I guess that would solve it. Switch aircon off would have been a test too.

This is my first warm week in the hybrid car. I remember that one of the reasons for not switching off ICE could be high temperature of the Battery pack. Inside of the car can get rather warm when parked in full sunlight exposure. Driving away on Battery power could maybe cause the Battery temperature to rise fast. No idea if that threshold is reached often and easily in summer.

[martin68]

I had a similar issue but in my case, last week i headed off for a 6 mile trip and the first two miles of this trip is down hill coasting, and all of my previous trips i was in ECO mode and driving electric, mainly charging the Battery, but on this occasion, the ICE never switched off and on the monitor the red arrows were driving the wheels, even though the Battery was nearly full.

It was in a coldish evening, so the heater dials were up to about 22 degrees and the fan speed was on first notch in the display, AC was off.

So is it simply because i tried to keep myself warm that the ICE stayed on for so long? Ide hate to find how this system works in the deep winter coldness.

[haelewyn]

In winter, it takes quite a while to warm up the engine.

Once it did, if you drive on electric, the ICE will still kick in as the engine temp easily goes down a few degrees.

This influences the mpg quite a bit. My classical daily ride is about 6 miles. Traffic lights at 300 meters. I changed the trip to avoid that traffic light as it ruins my mpg thoroughly. The 2 minutes I lose at 1400 revs stationary can not be erased in the rest of the 6 miles... I sometimes end up at about half (or even 1/3) the mpg I will do in summer on an ideal trip.

[martin68]

so basically you get about the same MPG in winter as you would with a conventional petrol only car? thats disappointing to learn, this makes diesel the winner once again.

[haelewyn]

Mpg changed after excluding the traffic light after 300 meters from my trip. I take an other route of about the same distance and that helps a bit. I try to make a distance while the ICE warms up.

There are other ways to get a better result in winter. Like : if you have a garage, use it (I don't have one) so the engine is a little less cold. 10 degrees or -2 already makes a large difference.

Try to do as many things as you can with a warm engine by combining your trips. For me this means taking the car out a few times a week and combine destinations. The car burns a lot less fuel on a warm start than on a cold one.

I take a bus more often and for the short occasional distance, I use my feet.  

I dont deny that the warming up of the ICE wastes some fuel. But I don't agree with your conclusion. Diesel cars pollute a lot while the engine is cold and with the dpf / egr problems on doing many small drives, they wouldn't be much fun nor cheap for you or me either. Or the car would try to regenerate constantly without success, so repeating the cycle every ride. That would also cause higher consumption.

The  hybrid car does have a worse mpg in cold weather compared to warm temperatures.. outside temp of 10 compared to 0 °C is a big difference on mpg as in freezing temperatures the engine will cool down while on electric driving,  being turned on to reach minimum threshold maybe several times. Also there is little or no benefit on highways where it easily goes to more than 6 liters per 100 km, depending on your speed. Those are the characteristics of the hybrid car.

Compared to diesel : my hybrid car does about 5 liters per 100 km at 100-110 km per hour. My corolla diesel did about 4,5 at 120. I solve this by doing 100 km per hour and using 4,5 to 5 liters per 100 km. At low highway speeds, the electric engine still assists and makes a difference. Speeds here are always real km per hour, measured on ultragauge device. I improve the mpg by ending up in stop and go traffic or 50 km per hour zo een before reaching my destination.

Sometimes hybrid characteristics can be used to your advantage.  Whenever there is a traffic jam, I do 0 liters per 100 most of the time and I feel very relaxed compared to before, driving the automatic gears. . I dont know what you expected but if it sounds too nice to be true, things are often not true.

[YarisHybrid2016]

The big killers in winter are the heater and the cold.

The advantage of hybrids (ability to drive all-electric) is also a problem because during periods of electric only operation, the engine cools, so it runs more frequently, and longer.

From what I can tell, the heater causes the engine to need to run warmer than when the heater is off (LO). I think I read somewhere that minimum coolant temp on these engines is 40 deg. C but this is increased to drive the heater. It seems to be the higher the set temperature, the longer the engine runs (higher temps are needed). In this way, even the heater is optimized as the engine doesn't get warmer than necessary.

If you really want to harm fuel economy, set the heater to HI. The engine runs almost constantly!

During the warm-up phase (now, this still takes a couple of minutes), you basically can't do anything to affect fuel economy. I've tried lots of things, and pretty much average 35-40 MPG in the first couple of miles, with one junction 2 miles down the road. Driving at 30 MPH or 60 MPH basically makes no difference, nor just how quickly you accelerate (I accelerate gently simply because everything is cold and I don't want to hammer the Battery or engine). Generally during warm up I accelerate at the tick mark one below POWER band. This gets me to speed without harming anything, and MPG at this point is pretty much fixed.

I'm not on a busy road during the period of warm-up so I limit my speed to 40-50 MPH. The car is noticably slower (less performance) when cold, so I limit my speed simply to limit how long I'm accelerating (it just burns fuel and the car doesn't really accelerate).

Another thing to know is the warm-up phase is timed (at least, it appears to be). CONSISTENTLY I can not exceed around 50 MPG until approximately 5 minutes after starting a journey. At pretty much the same point every time, I watch the fuel economy slowly increase (instantaneous figure) over a period of about 30 seconds. Once I start seeing instantaneous figures over 60 MPG, I know the warm-up is completed.

It is possible to get good economy in winter, but you need to do a couple of things:

* run the heater slightly lower than you might like (I find 19 C is good when it is freezing outside - it keeps the windows clear and the cabin is cool but not cold - note that I blast the heater initially, setting it to HI).

* Limit your speed to around 53 MPH. Faster just requires more use of the ICE, which only has a negative effect on consumption. 53 MPH seems to be the optimum speed for economy regardless.

* Ensure your tyres are the correct pressures! In winter I set them about 3 psi over normal to allow for colder temps.

* Use the climate control in AUTO.

This last point takes a bit of explaining:

If you run the fan at a high setting when trying to warm up the heater, it actually takes longer. In winter, in AUTO, the system can do something you can't do manually: IT SWITCHES OFF THE FANS COMPLETELY. This is NOT the same as you selecting OFF, as that switches off the entire system.

It depends if the cabin is misting up, but if it isn't, to get heat as fast as possible, I set the heater to HI and AUTO (fans switch off), and start driving. Eventually the system will start slowly increasing the fan speed. When it does, I then set the temperature I want. It seems to work effectively.

If the car is misting up, I set the heater on HI and AUTO, and wait about 5 minutes. I usually go back inside and watch the car as I'd only be adding to the humidity problem while it warms up!

I've also found the heater to be marginally more effective with recirc OFF. Does anyone know why this might be?

EDIT: Just noticed I'm posting in the Auris forum. I don't know how different the Auris system is from the Yaris, but I guess they would be similar (the heater works the same way).

[Anthony Poli]

12 hours ago, YarisHybrid2016 said:

The big killers in winter are the heater and the cold.

The advantage of hybrids (ability to drive all-electric) is also a problem because during periods of electric only operation, the engine cools, so it runs more frequently, and longer.

From what I can tell, the heater causes the engine to need to run warmer than when the heater is off (LO). I think I read somewhere that minimum coolant temp on these engines is 40 deg. C but this is increased to drive the heater. It seems to be the higher the set temperature, the longer the engine runs (higher temps are needed). In this way, even the heater is optimized as the engine doesn't get warmer than necessary.

If you really want to harm fuel economy, set the heater to HI. The engine runs almost constantly!

During the warm-up phase (now, this still takes a couple of minutes), you basically can't do anything to affect fuel economy. I've tried lots of things, and pretty much average 35-40 MPG in the first couple of miles, with one junction 2 miles down the road. Driving at 30 MPH or 60 MPH basically makes no difference, nor just how quickly you accelerate (I accelerate gently simply because everything is cold and I don't want to hammer the battery or engine). Generally during warm up I accelerate at the tick mark one below POWER band. This gets me to speed without harming anything, and MPG at this point is pretty much fixed.

I'm not on a busy road during the period of warm-up so I limit my speed to 40-50 MPH. The car is noticably slower (less performance) when cold, so I limit my speed simply to limit how long I'm accelerating (it just burns fuel and the car doesn't really accelerate).

Another thing to know is the warm-up phase is timed (at least, it appears to be). CONSISTENTLY I can not exceed around 50 MPG until approximately 5 minutes after starting a journey. At pretty much the same point every time, I watch the fuel economy slowly increase (instantaneous figure) over a period of about 30 seconds. Once I start seeing instantaneous figures over 60 MPG, I know the warm-up is completed.

It is possible to get good economy in winter, but you need to do a couple of things:

* run the heater slightly lower than you might like (I find 19 C is good when it is freezing outside - it keeps the windows clear and the cabin is cool but not cold - note that I blast the heater initially, setting it to HI).

* Limit your speed to around 53 MPH. Faster just requires more use of the ICE, which only has a negative effect on consumption. 53 MPH seems to be the optimum speed for economy regardless.

* Ensure your tyres are the correct pressures! In winter I set them about 3 psi over normal to allow for colder temps.

* Use the climate control in AUTO.

This last point takes a bit of explaining:

If you run the fan at a high setting when trying to warm up the heater, it actually takes longer. In winter, in AUTO, the system can do something you can't do manually: IT SWITCHES OFF THE FANS COMPLETELY. This is NOT the same as you selecting OFF, as that switches off the entire system.

It depends if the cabin is misting up, but if it isn't, to get heat as fast as possible, I set the heater to HI and AUTO (fans switch off), and start driving. Eventually the system will start slowly increasing the fan speed. When it does, I then set the temperature I want. It seems to work effectively.

If the car is misting up, I set the heater on HI and AUTO, and wait about 5 minutes. I usually go back inside and watch the car as I'd only be adding to the humidity problem while it warms up!

I've also found the heater to be marginally more effective with recirc OFF. Does anyone know why this might be?

EDIT: Just noticed I'm posting in the Auris forum. I don't know how different the Auris system is from the Yaris, but I guess they would be similar (the heater works the same way).

No difference between the two, of ours. In the Yaris we have the air con set at 21 using auto. With the Eco driving mode, In the warmer weather, we haven't seen much of a dip compared the air con switched off. still getting 75mpg on the A road with a 50 mph limit and 6 sets of traffic light for a 10 mile trip. On my short commute to work in the Auris, Have the air con/ heating off for my 3.5 mile commute in the mornings. As the engine never gets warm enough to heat the cabin, just like my previous non hybrid car. When I worked at my previous job, one of the other engineers used to block off the radiator grill to help speed up the diesel van to warm up the cabin.

The air con on gen 3 hybrids uses less fuel than the gen 1 and 2, since the compressor is electrically driven. 

[Anthony Poli]

I forgot to add, on Auto the air con switches off once the temperature has been reached and switches back on once the temperature changes.

 

[YarisHybrid2016]

Interesting. I was under the impression that having the heater set resulted in additional fuel burn any time, as heat from the ICE is needed (and it needs to be way above ambient to function).

Does the air blow cold or cool in this situation? Obviously with running LO, I get freezing cold air!   It does mean however that the ICE isn't running for heat.

Does your Yaris have the glass roof? Maybe you can answer something I wondered: do you find any amount of sunlight, or just daylight in summer, is sufficient to warm the car? Even in winter during the day I don't need the heater. However, any time of year (unless it has been 25+ C in the day), as soon as the sun drops below the horizon, I feel a distinct drop in temperature. In winter this necessitates turning the heat up. I feel the cabin temp drop over the period of a minute or two. It's really quite interesting.

[Anthony Poli]

1 minute ago, YarisHybrid2016 said:

Interesting. I was under the impression that having the heater set resulted in additional fuel burn any time, as heat from the ICE is needed (and it needs to be way above ambient to function).

Does the air blow cold or cool in this situation? Obviously with running LO, I get freezing cold air!   It does mean however that the ICE isn't running for heat.

Does your Yaris have the glass roof? Maybe you can answer something I wondered: do you find any amount of sunlight, or just daylight in summer, is sufficient to warm the car? Even in winter during the day I don't need the heater. However, any time of year (unless it has been 25+ C in the day), as soon as the sun drops below the horizon, I feel a distinct drop in temperature. In winter this necessitates turning the heat up. I feel the cabin temp drop over the period of a minute or two. It's really quite interesting.

For me 21 is a comfortable temperature for both summer and winter, in winter the trips in the Yaris are long enough to allow the engine to warm up and keep warm while still allowing it to switch to EV. the downside is less mpg. Around here we haven't had any really cold winter in the 12 months of having the Yaris. So the mpg hasn't been below 50.

Last weekend, I still managed to get 73mpg despite going into the power zone a few times for less than a minute each time and stopping for traffic lights.

The Auris is quicker 1.8 v 1.5, but the results aren't that much lower. With driving both cars, it has helped me fine tune my techniques more.

 

[YarisHybrid2016]

I'm weird - I like the cold! Minus 10 C and I'm that nutter in shorts and t-shirt! 

I only use the heater in winter to stop the car misting up! 

[haelewyn]

Recirc on or off, I see 2 differences :

- Cold outside air contains less humidity than the one inside. In general, cold air is not capable of containing as much humidity as warm air. That's why cookies and cake keep fresh or crispy longer inside the fridge. I can imagine that the climate control has less work on conditioning moisture from outside air compared to recirculated air.

- While driving, outside air flows inside easily. Driving 30 mph already facilitates the air to come inside quite a lot.  In recirculation position,  the system needs to suck up and blow back in the air in the car which is less efficient. 

I personally try to select Recirc off as much as possible and would only use this feature in tunnels.

In winter, 17 or 18 degrees is warm enough for me in the car, as I am wearing warm clothes at that time. I must concentrate more on not asking the car to blow warm air when doing short drives. I switch the fan to low but still the temperature I select (18) will make the engine heat up.  I have the heated seats and simply love that function. Keeps me warm even if i dont use the heater. 

I didn't even notice there was a LO position for winter. Thought there were only numbers. I will select that one later and try it out.

My Auris has the glass roof but I keep it covered not to be damp so much it would drip on me. I did use aircon on long drives to get the moist off and that took quite a while. I felt no warmth from it in winter when it was open. A lot of light coming inside though, which I noticed while opening it in darker weather. On warm days, it does add heat though. And it started making a noise from vibrating. That sucks a bit as I hate it.. The dealer says they can fasten it again and it's caused by the rail. They would have to do the same thing every year to stop the noise. It's known to start when first heat comes..

What is the difference in choosing left and right , f.e. 20 degrees, with or without switching automatic on. I usually don't use auto in winter but I do in summer. Might change that if I understand things better.

Selecting a temperature that is more than 8 degrees difference to the outside one seems to me like causing adaptation problems after driving. In winter, could solve that by wearing extra clothes outside the car. In summer... there is no real solution.

Aircon is electric, but the engine will run more often, longer and the Battery will drain more when real cooling of the interior is asked.

[Anthony Poli]

Recirc on or off, I see 2 differences :

- Cold outside air contains less humidity than the one inside. In general, cold air is not capable of containing as much humidity as warm air. That's why cookies and cake keep fresh or crispy longer inside the fridge. I can imagine that the climate control has less work on conditioning moisture from outside air compared to recirculated air.

- While driving, outside air flows inside easily. Driving 30 mph already facilitates the air to come inside quite a lot.  In recirculation position,  the system needs to suck up and blow back in the air in the car which is less efficient. 

I personally try to select Recirc off as much as possible and would only use this feature in tunnels.

In winter, 17 or 18 degrees is warm enough for me in the car, as I am wearing warm clothes at that time. I must concentrate more on not asking the car to blow warm air when doing short drives. I switch the fan to low but still the temperature I select (18) will make the engine heat up.  I have the heated seats and simply love that function. Keeps me warm even if i dont use the heater. 

I didn't even notice there was a LO position for winter. Thought there were only numbers. I will select that one later and try it out.

My Auris has the glass roof but I keep it covered not to be damp so much it would drip on me. I did use aircon on long drives to get the moist off and that took quite a while. I felt no warmth from it in winter when it was open. A lot of light coming inside though, which I noticed while opening it in darker weather. On warm days, it does add heat though. And it started making a noise from vibrating. That sucks a bit as I hate it.. The dealer says they can fasten it again and it's caused by the rail. They would have to do the same thing every year to stop the noise. It's known to start when first heat comes..

What is the difference in choosing left and right , f.e. 20 degrees, with or without switching automatic on. I usually don't use auto in winter but I do in summer. Might change that if I understand things better.

Selecting a temperature that is more than 8 degrees difference to the outside one seems to me like causing adaptation problems after driving. In winter, could solve that by wearing extra clothes outside the car. In summer... there is no real solution.

Aircon is electric, but the engine will run more often, longer and the battery will drain more when real cooling of the interior is asked.

 

The air recirculating is controlled automatically, when auto is selected.

 

 

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[haelewyn]

Fan is working automatically while in auto position, the temp of the air is controlled by f.e. setting 20 degrees. Would the climate control make the output air warmer and colder again to reach 20 in the interior on manual while the fan is just on the speed that was selected ?

I find most cars are ok in getting there the first time but not afterwards.. in maintaining the temperature. That's where my doubts lie..

I often select the front window "defrost" sign in winter. I think if I do different, it will get damp half of the times I drive the car. 

I love the system ford uses, with the heating wires in the front screen. Wish toyota used those too.

[st901]

For short trips in the winter we usually use the  seat warmers   with the heater switched off ,  provided the windscreen is clear .

In the summer driving with the  windows wound down  rather than use the a/c will also save fuel at speeds below 30mph .

[YarisHybrid2016]

Curious you get water dripping off the roof! Wow.

LO setting means no heat - if the AC is on it will be freezing. In day time this is fine, especially if you direct the air so it's not blowing directly on you with the fan on min. It's enough to keep the glass from misting.

I use recirc heavily as traffic, even going down a busy road away from built-up areas, is such there are very strong smelling fumes from other vehicles. Tests have shown that cars concentrate pollutants, so I clear out the cabin in the countryside then use recirc to try and keep the nasty stuff out. Despite this, I still find I can smell diesel fumes sometimes, but not nearly to the extent that I would if recirc was off.

If the air is clear, then I sometimes switch off the aircon completely (OFF), and open the recirc directed into the face vents. The ram air effect is incredible! It's the most effective I've experienced, so I'm guessing Toyota really thought about this! I find I can't do it for long though, as the car eventually mists up.

[haelewyn]

Dripping : didn't have that yet, but rather a lot of water is accumulating on the inside of the roof when i leave the cover open. No idea what happens when it is closed.
Until now the water didn't drip down yet.  I want to avoid that ... I think it's a not so nice idea :)

[Anthony Poli]

10 hours ago, haelewyn said:

Fan is working automatically while in auto position, the temp of the air is controlled by f.e. setting 20 degrees. Would the climate control make the output air warmer and colder again to reach 20 in the interior on manual while the fan is just on the speed that was selected ?

I find most cars are ok in getting there the first time but not afterwards.. in maintaining the temperature. That's where my doubts lie..

I often select the front window "defrost" sign in winter. I think if I do different, it will get damp half of the times I drive the car. 

I love the system ford uses, with the heating wires in the front screen. Wish toyota used those too.

When the climate control is on Auto, it will provide heat or cold as required. once the temperature is reached it will turn off until it needs to warm or cool.

[haelewyn]

I am under the impression that it makes a difference if i switch 'AUTO' off and low fan speed.   At time of my small test, it was 21 degrees outside (hot in the car cause there was a lot of sunshine) and selected 20 degrees;   Battery still draining fast on AUTO.   A little later (most of the work done by then), on manual and low fan speed, there was a lot less Battery consumption.
I guess it makes a big difference if the car needs to be cooled down from 30 to 20 degrees or just needs to be kept on temperature.

Also in the hybrid : big difference between city and highway driving. On highway, one could always add more power to the HV batt than what we take. On driving towards the highway, I am usually already consuming a lot of power from the batt as I would be driving 50 km per hour on electric engine only. Add the aircon powercooling the car down, that is too much for the thing..

Also wonder if driving 5à or 60 + powercooling is not asking too much power from the Battery at once, but I guess it's protected on that and a maximum power demand is programmed. Maybe there is also the reason why the engine doesn't switch of in these circumstances (looking at it from an other angle).

[Anthony Poli]

On a short test, you might not see the benefits of using auto, but on longer journeys it will adjust accordingly and it will even switch off while the set temperature is reached.

 

If I am stuck in stationary traffic, I prefer to open all 4 windows a little. Then close the windows and put the ac back on, once the traffic starts moving freely.

 

 

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