blimpy
Posts: 115
Joined: Mon Nov 03, 2014 12:36 pm
Delivery Date: 0- 0-2014

Technical: How Does The Hybrid Heater Work - specifically ?

Sun Nov 20, 2016 2:43 pm

The purpose of this thread is Technical, to understand the components in the Hybrid Climate Control System, and how they function as a system.


my car is a late 2016 30KwH SV I have read through the Using the Heater Efficiently thread.

From that, I picked up some ideas that may or may not be correct about the Climate Control System,
what it is composed of, and how it may work.

What I think is true:

The heater is composed of 2 parts 1. A Heat Pump.. basically a Freon compressor/evaporator that can Heat or Cool.
2. A Resistance Type Heating Coil ( someone referred to as PTC heater ??)
essentially the same as the only heater in 11-12 and S models.

My understanding is:

A) The heat pump uses waste heat from the liquid cooled motor controller and DC-DC inverter to augment or provide heating/cooling.
Energy consumption appears to be about 500 watts 1/2 Kw. for the Heat Pump.

B. The Resistance Heater is also used at times during the heating or defrosting cycle. and Draws 1500 to 3000 watts
1.5 to 3 Kw.

C. The Auto Mode controls the above, plus vents and recirc air .

D. Both Resistance and Heat Pump work simultaneously at some times.

Q #1. Is any of the above incorrect.
Q #2. How do I prevent the Resistance Heater from coming on while driving ?
Q#3. Is defrosting possible without the resistance heater ?

Q#5. How does the system switch between Resistance, Heat Pump and combined Heat/AC operation..
and most important what controls or over-rides do I have ?

As an aside.. I was shocked when I saw the heater/defroster drawing 1500 watts and dumbfounded when I saw 3Kw !
of course this was when the car was stone cold. Foolish me.. I had no idea the car still had a resistance heater !
Spent big money over the S-30 just to ditch that !

anyway.. I would really like to understand the components in the system.. and how they are programmed to
function ( by Nissan) and how I can control them... with out the hot water bottle and lap blanket anecdotes. ;)
2016 SV purchased 11/2/16 With Subsidies From Sonoma Clean Power, North Sonoma Air Pollution Control District, Evergreen, and State of California, and $15,000 in discounts from Jim Bone Nissan Santa Rosa California. :D Color Me GRATEFUL Long Time Coming !

arnis
Posts: 753
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Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: Technical: How Does The Hybrid Heater Work - specifically ?

Sun Nov 20, 2016 5:06 pm

Mostly incorrect unfortunately.
viewtopic.php?f=27&t=15108&start=20#p475574
I made a post that answers some things you asked.

If you want to know how heat pump works then just google search how normal
air-air inverter split type heat pumps work.

Resistance heater is not heating water like on older Leafs. It directly heats air in the
heater box. Faster and little bit less losses.

Defrosting can be done without heating up the air after dehumidifying but is not that effective.
I rarely switch to pure clean-windscreen button. Just change airflow to windscreen and
double click recirculation button to "fresh air" mode. AUTO mode is recirculating ~30%.
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Scaramanga
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Leaf Number: 308884
Location: Tacoma, WA

Re: Technical: How Does The Hybrid Heater Work - specifically ?

Mon Jun 12, 2017 5:44 am

blimpy wrote:
As an aside.. I was shocked when I saw the heater/defroster drawing 1500 watts and dumbfounded when I saw 3Kw !
of course this was when the car was stone cold. Foolish me.. I had no idea the car still had a resistance heater !
Spent big money over the S-30 just to ditch that!


Ditto, I was surprised to find the same thing. Mind you I like the heater / A/C performance just fine, but I thought the whole thing was a heat pump with no resistance backup. I need a diagram I think.
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blimpy
Posts: 115
Joined: Mon Nov 03, 2014 12:36 pm
Delivery Date: 0- 0-2014

Re: Technical: How Does The Hybrid Heater Work - specifically ?

Mon Aug 07, 2017 3:51 pm

thanks arnis for link to tech thread with diagrams on heat /AC system.

mine uses progressively less power as the interior temp approaches the thermostat setting.
it will go from 3 kw to 1.5 kw pretty quickly.. and then step wise down to 500 watts.. and that cycles on and off
to maintain temp.

So it is a pretty smart and flexible system.

We haven't had driving temps below 40 F.. and set the cabin temp between 69 and 72.
no not the ice and snow some get in spades.

heat/ac is so good ( 2016) .. we just don't worry about using it with the 30KwH battery.
mostly.
2016 SV purchased 11/2/16 With Subsidies From Sonoma Clean Power, North Sonoma Air Pollution Control District, Evergreen, and State of California, and $15,000 in discounts from Jim Bone Nissan Santa Rosa California. :D Color Me GRATEFUL Long Time Coming !

LeftieBiker
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Delivery Date: 31 May 2013
Location: Upstate New York, US

Re: Technical: How Does The Hybrid Heater Work - specifically ?

Mon Aug 07, 2017 4:44 pm

A) The heat pump uses waste heat from the liquid cooled motor controller and DC-DC inverter to augment or provide heating/cooling.


NO. The Bolt scavenges waste heat from the electronics, but has no heat pump. The Leaf has a heatpump, but AFAIK it doesn't scavenge heat from the electronics. It gets it from the ambient air.
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