Heat Pump Efficiency at 110degrees

[h82fuel]

I'm concerned if the heat pump will keep the car cool when the Arizona temperature is at 110 degrees. I live in Arizona. My understanding is the heat pump doesn't work well at really low or high temperatures. Anyone with experience with heat pumps?

 

[mboni]

When cooling the car, a heat pump is essentially identical to a regular air conditioner of the same size. I think you'll be fine, but I'd suggest you don't get a black car if you need to park in the sun.

 

[RichAZ/CapeCod]

When cooling the car, a heat pump is essentially identical to a regular air conditioner of the same size. I think you'll be fine, but I'd suggest you don't get a black car if you need to park in the sun.

Yeah, white would be the most logical color (wife and I are in AZ). But wifey wants a blue MY, so there you are!

Rich

 

[dhrivnak]

A heat pump IS an air conditioner that can also run backwards to make heat.

 

[garrett5688]

The reason you don’t see heat pumps in ICE is because you’d have to run the crank backwards

 

[MY-Y]

One video indicated it didn't work well in every cold weather. It would be great to have the vent temp measured on a very cold day.

 

[Jeff3820]

All an air conditioner, and any refrigeration system, does is take energy like heat and move it to another location...usually outside the cabin or outside a refrigerator. Air conditioners don't make cold, they remove heat from one location and move it elsewhere. Condenser is outside the cabin/refrigerator cabinet and the evaporator is inside the cabin or refrigerator. Heat moves from evaporator to the condenser.

Heat pumps are more advanced...they also move energy/heat from one location to another but they can be equipped with multiple evaporators and condensers...one of each inside the cabin, and another pair outside. In some systems with appropriate valving an evaporator or condenser (just a heat exchanger) can do both jobs but lets keep this simple. So if a heat pump moves energy/heat from the cabin to outside then it is cooling. If moving heat from outside the car to the cabin it is heating. So think of a heat pump like your heart moving blood from one organ to another. That is how Tesla uses it according to their patent. So in the winter where does the heat pump get energy when it is 0 degrees outside? Well, it can get some from outside but the heat pump can also get heat from the motors, and the battery. All of the energy systems are interconnected and the octovalve in conjunction with the heat pump directs energy/heat where it is needed. The heat pump can also heat the motors and the battery. To get rid of excess heat/energy there is a radiator in the front of the model with electronic louvers that can open and close to regulate efficiency and aerodynamics. This is really a very advanced temperature control system!

 

[Evoforce]

I'm concerned if the heat pump will keep the car cool when the Arizona temperature is at 110 degrees. I live in Arizona. My understanding is the heat pump doesn't work well at really low or high temperatures. Anyone with experience with heat pumps?

Don't worry, enjoy it because it will make you too cold.

 

[MY-Y]

All an air conditioner, and any refrigeration system, does is take energy like heat and move it to another location...usually outside the cabin or outside a refrigerator. Air conditioners don't make cold, they remove heat from one location and move it elsewhere. Condenser is outside the cabin/refrigerator cabinet and the evaporator is inside the cabin or refrigerator. Heat moves from evaporator to the condenser.

Heat pumps are more advanced...they also move energy/heat from one location to another but they can be equipped with multiple evaporators and condensers...one of each inside the cabin, and another pair outside. In some systems with appropriate valving an evaporator or condenser (just a heat exchanger) can do both jobs but lets keep this simple. So if a heat pump moves energy/heat from the cabin to outside then it is cooling. If moving heat from outside the car to the cabin it is heating. So think of a heat pump like your heart moving blood from one organ to another. That is how Tesla uses it according to their patent. So in the winter where does the heat pump get energy when it is 0 degrees outside? Well, it can get some from outside but the heat pump can also get heat from the motors, and the battery. All of the energy systems are interconnected and the octovalve in conjunction with the heat pump directs energy/heat where it is needed. The heat pump can also heat the motors and the battery. To get rid of excess heat/energy there is a radiator in the front of the model with electronic louvers that can open and close to regulate efficiency and aerodynamics. This is really a very advanced temperature control system!

I agree with you. I'm still concerned about how warm it blows on fridged days. My home heat pump has a massive resistive heater when it gets too cold. If the MY still had the ~7kw resistive heater as backup, I'd have no concern. It'd be great if a MY owner that still has a real cold morning to experiment would report on duct temperatures. Even a subjective "it blows toasty warm in less than five minutes" would be reassuring.

 

[Jeff3820]

The patent describes a small resistive heater it’s probably there if needed. However, the patent also describes operating the motors in a special mode to also produce additional heat...basically a less efficient mode that produces some waste heat...just like an ICE vehicle.

 

[animorph]

Our Model 3 and Model X are great for A/C in the summer in Scottsdale. Trust that Tesla knows what they're doing with the Model Y.

 

[destructure00]

The reason you don’t see heat pumps in ICE is because you’d have to run the crank backwards

That's not quite right...

 

[MY-Y]

The patent describes a small resistive heater it’s probably there if needed. However, the patent also describes operating the motors in a special mode to also produce additional heat...basically a less efficient mode that produces some waste heat...just like an ICE vehicle.

With the resistive heater being small and the special mode being something novel, a real world experience would be good to hear. One of the YouTube videos mentioned didn't get that warm when they were driving with the outside temp in the 20's. It was just a casual comment though.

Anyone experience duct temps in the cold? If we dont find out soon, it'll be six months before we know.

 

[h82fuel]

Thanks for all that responded. I think I have my answer.

 

[Georgia_Y]

I'm sure you guys do it in AZ, but a good window film will help a lot. The Y (as well as other Teslas) will moderate the cabin temperature which means less time spent cooling it down so that the HVAC system only has to maintain a temperature.

 

[Uncle Paul]

Tesla does include resistance heater as well with their new heat pumps.

In very cold weather they will generate internal heat by taking waste heat from their electric motors or from discharging Li Batteries.
Heat pump will scavage this heat to make their heat pumps more effective.

They can either apply some current to the motors to warm them up or direct regenerative braking heat to the Heat Pumps.

Think they got this all figured out.

Computer will shunt any available heat source to make your heat pump more effective.

 

[mongo]

I agree with you. I'm still concerned about how warm it blows on fridged days. My home heat pump has a massive resistive heater when it gets too cold. If the MY still had the ~7kw resistive heater as backup, I'd have no concern. It'd be great if a MY owner that still has a real cold morning to experiment would report on duct temperatures. Even a subjective "it blows toasty warm in less than five minutes" would be reassuring.

Per the patent, the compressor can be run in a lossy manner such that it becones a heater. Same sort of thing as using the drive unit to heat the pack.
One embodiment has the electronics/ stator boiling the refrigerant before it is introduced to the compressor mechanism.
The mechanical work done by the compressor also generates heat.
The cabin blower could also be used that way, and there are two low voltage heaters for dual zone control plus aux heat.

 

[Uncle Paul]

I believe the main job of the Octovalve is to shunt heat/cooling where ever it is most needed and most efficient.

Believe Tesla is far ahead of their competitors in this regard.

 

[jeffpaz]

it blows toasty warm in less than five minutes.
Got mine in March and live in Minneapolis. It went from 20 degrees to 65 in 5 minutes.

I agree with you. I'm still concerned about how warm it blows on fridged days. My home heat pump has a massive resistive heater when it gets too cold. If the MY still had the ~7kw resistive heater as backup, I'd have no concern. It'd be great if a MY owner that still has a real cold morning to experiment would report on duct temperatures. Even a subjective "it blows toasty warm in less than five minutes" would be reassuring.

 

[Mike MY]

Thanks jeffpaz. First actual feedback like this I’ve been able to find. Glad to hear it works well in 20 degree temps!