2013 and forward heat pump questions

[kieranmullen]

Household heat pumps have heating strips or coils that operate as a backup when there is not enough heat to extract from the air.

Does anyone know if there are backup heating strips and what the size of them are? (compared to say my 2012 heating strips )

Thank you

 

[TomT]

The backup is a resistance heater in the fluid loop ala the 2011, 2012 Leaf...

 

[knightmb]

Household heat pumps have heating strips or coils that operate as a backup when there is not enough heat to extract from the air.

Does anyone know if there are backup heating strips and what the size of them are? (compared to say my 2012 heating strips )

Thank you

They have backup resistive heaters if the heat pump can't function from being too cold. That is where 6 kW of energy can go in that example. If you live in climates where the temperature outside is often colder than the heap pump can handle, you'll notice a bigger power drain when the heat is running.

 

[kieranmullen]

So in terms of size it is the same heater just with a heat pump then? I was told that the 2012 did better in colder climates but it would not seem likely if the heater is the same size. Thank you!

Household heat pumps have heating strips or coils that operate as a backup when there is not enough heat to extract from the air.

Does anyone know if there are backup heating strips and what the size of them are? (compared to say my 2012 heating strips )

Thank you

They have backup resistive heaters if the heat pump can't function from being too cold. That is where 6 kW of energy can go in that example. If you live in climates where the temperature outside is often colder than the heap pump can handle, you'll notice a bigger power drain when the heat is running.

 

[LeftieBiker]

So in terms of size it is the same heater just with a heat pump then? I was told that the 2012 did better in colder climates but it would not seem likely if the heater is the same size. Thank you!

The resistance heater seems to be, IIRC, exactly the same model used in earlier Leafs. Also, it works with the heatpump at lower temps, not just alone when the heatpump can't function.

 

[cwerdna]

So in terms of size it is the same heater just with a heat pump then? I was told that the 2012 did better in colder climates but it would not seem likely if the heater is the same size. Thank you!

It was probably because of the forced features on the '12: http://www.autoblog.com/2011/07/19/2012-nissan-leaf-higher-price-tag-standard-equipment/" onclick="window.open(this.href);return false;. I doubt the heater changed at all on between the '11 and '12.

 

[RonDawg]

I was told that the 2012 did better in colder climates but it would not seem likely if the heater is the same size.

Except for the addition of heated seats and steering wheel as standard equipment, I had never heard of the 2012 models having a superior heating system.

It has been mentioned a few times in this forum that the 2011-2012 cars seemed to have a better air conditioner than the later heat-pump-equipped models.

 

[TomT]

Yes, if you live in a primarily warm climate, the system on the 2013 and forward was actually a step backwards as it is less efficient. It could have been made nearly as efficient as the AC on the 2011 and 2012 but that would have required a more expensive proportional valve...

It has been mentioned a few times in this forum that the 2011-2012 cars seemed to have a better air conditioner than the later heat-pump-equipped models.

 

[bradbissell]

I found out the hard way what happens when the resistive heater fails and the temperature is too cold for the heat pump to function. The heat pump will completely turn off when the temp is below 15F. In my case, I drove to work when it was -3F. Thank goodness I had heated seats and steering wheel.

 

[johnrhansen]

Old style residential heat pumps do indeed have resistance strips or a backup gas burner. In fact the whole system is usually centered around a standard electric or gas furnace. The heat pump condenser coil is just inline with the air fed from the furnace. When the outdoor coils are operated in a damp environment, the coils will begin to ice up due to the moisture in the cool damp outside air hitting the cold evaporator coils. The heat pump can sense this, and operates a reversing valve reversing the flow of refrigerant. This heats up the outside coils and cools down the inside coils. the resistance strips come on so that the occupants of the home remain comfortable and don't experience a blast of freezing air from the ductwork. The ice melts off and falls away. Then the system reverts back to a heat pump. You can turn off the strip heaters and the system will still function, but you will feel that cold blast and the deice cycle will last longer.

More modern systems, (ductless mini splits) do not have resistance strips. It just turns off the inside fan and just lets the waste heat of the compressor heat the outside coils, therefore the deice cycle takes longer, and all you feel is a lack of heat, just like the system is off.

I have no idea how the leaf system works, but I'd bet its more like the second system than the first.

 

[LeftieBiker]

The old resistance-strip-based systems weren't much good below freezing, so the Leaf obviously uses the more modern configuration. There is a whole second heater rather than a heating element for the heat pump. I've looked into the modern systems now, and the mini-splits aren't the only type of low-temp heat pump system available - there are also full-sized, whole-house ones that will provide useful heat to about 18F.

 

[Nhinman]

I have a 2015 SV Leaf, and it does not use a water circulation system with the electric heating element.
I don't what year they quit using the water circulating system.

 

[johnrhansen]

I've been told my 2013 s model uses an air heater system.

 

[knightmb]

I've been told my 2013 s model uses an air heater system.

I have one and it's true, no duct-work for anything other than AC. The heater is all self-contained and will easily bbq you after a few seconds when you start the vehicle. Feels great when it's really cold outside, but plays hell on range as that 6kw heater literally knocks off 10 miles from the GOM just by turning it on or off for fun. :mrgreen:

 

[LeftieBiker]

We need a description of the current hybrid heating system, obviously...

 

[johnrhansen]

I was told its the same. Just the ac system has the ability to reverse itself.

 

[TomT]

Correct. All they did was add reverse cycle capability which essentially requires the addition of a valve...

I was told its the same. Just the ac system has the ability to reverse itself.

 

[johnrhansen]

I wonder if converting a s to a heat pump would be as simple as adding a reversing valve and another expansion valve on the heat pump side. I think you'd also need some kind of system to detect icing on the evaporator coils outside when running in heat pump mode and reverse it to melt it off again..

 

[GerryAZ]

I don't see any liquid lines and water heater tank under the hood on my 2015 like the 2011 had. Therefore, I suspect it is a dry heating element in the duct work somewhere. Also, it has been warm enough to use the A/C the past couple of days and I cannot tell any difference in efficiency compared to the 2011 (in cooling mode).

Gerry

 

[LeftieBiker]

The gen I AC is more efficient, but it isn't as if the heat pump A/C is an energy hog. I only lose about 2 miles of range to A/C on a typical 30-40 mile trip. Really hot weather might take an extra mile or so.