Air Conditioner Test Drive at 98F

[ArthurL]

Ive been having fun doing some hypermiling lately. Since my last full charge I had driven 251 km using 27.9 kWh and had 287 km remained mid marker for a combined potential range of 538 km. Pretty sweet but I had to do a full charge because I had a long distance run last two days of a 370 km out and back if I didn't have to deviate from route. Plenty of chargers along the route so I knew there were no issues.

After a full charge she showed a 533 km mid range marker. I'm shocked but I know that was because it was basing that on the previous hypermiling test and knew that was not gonna hold up on the trip. I'm thinking it 98 F outside so AC is a must (wife and grandson on board) and I can get a real test of the effect of AC usage on mileage. I set the AC at 68 F and away we went. I finished the trip with 385 km traveled with 80 km remaining for a potential total of 465 km. The energy usage also told me 93 percent of energy was propulsion and 7 percent accessory (AC).

When I got home I took the Bolt down to my local free level 3 (thank you BC Hydro) charged to 80 percent then back home to top her off to full on my level 2. Right now she shows 448 potential range on the mid marker.

For a car with EPA rating of 380 km it's pretty incredible I think. Never babied her. Over mountains and through a few towns. Cruise control when I could and a maneuvering burst when needed. AC chilled the whole way. Just the way I would have driven an ICE. I know the heat helps and winter will be a whole new ball game but I'm more impressed by this car every day.

What's your experience with AC over long distance?

 

[gpsman]

My experiemce is similar to yours.
A/C much to my surprise takes only 1 kw on high setting. Since I'm in CA will probably use A/C more than heat. Although being in coastal CA it may be 50/50.

On the other hand, why should it take more than 1kw? Those 120 VAC window air conditioners plug into a standard socket and cannot draw more than 1.8 kw.

My QUESTION is, which is better?

Run Full Cold (Lo) with low fan?

Or run 68-70'F with fan on medium or high?

On an ICE car, when you pick an intermediate temperature, the car BLENDS 42 degree air from the A/C evaporator with hot air from the engine to "make" 72 degree air.

I want to make sure the Bolt is not blending cold air and hot air to make mild air. That would waste energy.

 

[DaveInAvl]

A/C much to my surprise takes only 1 kw on high setting.

That would account for one aspect of our test drive a couple of weeks ago. The temperature was in the upper 90s and it seemed a long time before the air from the vents was noticeably cooler. Our LEAF cooled off much more quickly than that...

Wonder if Chevrolet might be limiting the amount of power the A/C can draw, to improve the EPA mileage rating? Does that test involve A/C use?

 

[devbolt]

A/C much to my surprise takes only 1 kw on high setting.

That would account for one aspect of our test drive a couple of weeks ago. The temperature was in the upper 90s and it seemed a long time before the air from the vents was noticeably cooler. Our LEAF cooled off much more quickly than that...

Wonder if Chevrolet might be limiting the amount of power the A/C can draw, to improve the EPA mileage rating? Does that test involve A/C use?

I've seen A/C on high pull as much as 3 kW when initially cooling down the car. Opening the windows to vent out the hot cabin air helps a lotto get the cabin cool. It does quickly settle down to ~1 kW for normal usage after that.

 

[GetOffYourGas]

Generally speaking, EVs take a much smaller hit from A/C than from heat. This throws a lot of people, since ICEVs (which we are all used to) are the opposite. An ICE has lots of "free" waste heat to use. But the A/C adds a mechanical load to the engine.

One of the things I love about an EV is that the A/C is not mechanically driven by the motor, but has its own motor. What this means is that the car actually provides full performance with the A/C on full blast. In my old civic, turning on the A/C would noticeably slow down the car. I would sometimes have to turn off the A/C if I wanted to pass another car on a two-lane road for example.

I want to make sure the Bolt is not blending cold air and hot air to make mild air. That would waste energy.

I'm not convinced this is true. By mixing cold and hot air, the car has to cool a smaller volume of air in the first place. Efficiency of the compressor aside, it takes the same amount of energy to remove X joules of heat from the air as it does to remove 2X joules of heat from half as much air, and then mix it with uncooled air.

 

[PV1]

That's great to hear. My 238-mile EV might turn out to be a 280-290 mile EV (as my i-MiEV has accustomed me to conservative driving on longer stretches).

In regards to the A/C, the i-MiEV has a manual temperature dial. Fan only operation is indicated by a green dot position between heat and cool. The further away from the green dot, the larger the temperature change provided by the heater or A/C. If I push the A/C button while on the green dot, it cycles the A/C unit between its lowest speed and off to maintain a very small temperature difference (although its usually enough to keep the car from getting hot). The further I turn the dial towards C, the higher the pressure difference the system maintains, which translates into colder air. It doesn't blend air at all, but instead varies the compressor to make the coil colder or warmer based on the setting.

The same occurs with the heater. The first notch into the red heats the coolant to about 90 degrees, which is enough to maintain a pre-heated interior, but the top notch heats the coolant to about 140-150 F.

I would imagine the Bolt's HVAC system works similar to this, but I haven't had much of a chance to play with it yet. What I've noticed so far, is that a manual fan setting and a 70 F set point puts out some COLD air that doesn't really vary in temperature. During test drives, the fan seemed to just slow down without changing the airvent temperature.

 

[ArthurL]

Apparently Consumer reports agrees. Bolt out distances the exaggerated range of all Tesla tested. I'm not into trashing Tesla. But this is very interest.

https://www.consumerreports.org/2017-chevrolet-bolt/chevrolet-bolt-sets-electric-vehicle-range-record/

 

[GetOffYourGas]

Apparently Consumer reports agrees. Bolt out distances the exaggerated range of all Tesla tested. I'm not into trashing Tesla. But this is very interest.

https://www.consumerreports.org/2017-chevrolet-bolt/chevrolet-bolt-sets-electric-vehicle-range-record/

This is worth discussing, but warrants its own thread.