Tap into vehicle passenger cabin cooling/heating

Does anyone know how one might determine whether a Leaf has the liquid-based heating/cooling circuit I've seen mentioned in a few other posts? I'm curious how closely coupled the two systems are; is the heating liquid what circulates through the cabin heat exchanger, or are there separate exchangers for heating and cooling? How cold can the liquid coolant be chilled?

I ask for a very simple reason: I'm looking to dump up to a few thousand watts of heat through a liquid-liquid or liquid-gas heat-exchanger and need a way to chill the working coolant. You can probably guess what the source of heating is (or will be). Since I'll be linking to the vehicle CAN through one point or another (take a guess why) it would be much simpler (and cheaper, and safer, and lighter...) to tap into the vehicle's HVAC rather than install an entirely separate one elsewhere on the car.

If there are resources or schematics for the HVAC system available, it would be awesome to see!

Additionally, any information on controlling the HVAC through VehicleCAN would be very helpful. Things like registers for setting pump speeds, target temperatures, or for reading temperature sensors...

I hope to share more about this project going forward, and I think it's an idea lots of you will like.

Just found the service manual linked in the previous thread. Should be set!

The lousy, inefficient liquid based heating system is found only on the 2011-2012 Leaf. The coolant is NOT chilled.

LeftieBiker said:

The lousy, inefficient liquid based heating system is found only on the 2011-2012 Leaf. The coolant is NOT chilled.

Click to expand...

Later models have a single AC compressor capable of both heating and cooling, correct?

coleafrado said:

LeftieBiker said:

The lousy, inefficient liquid based heating system is found only on the 2011-2012 Leaf. The coolant is NOT chilled.

Click to expand...

Later models have a single AC compressor capable of both heating and cooling, correct?

Click to expand...

Some of the 2013+ Leafs have a heat pump, but it is an air system, not liquid-based. You could work with it, but you'd need to fabricate a heat exchanger.

LeftieBiker said:

coleafrado said:

LeftieBiker said:

The lousy, inefficient liquid based heating system is found only on the 2011-2012 Leaf. The coolant is NOT chilled.

Click to expand...

Later models have a single AC compressor capable of both heating and cooling, correct?

Click to expand...

Some of the 2013+ Leafs have a heat pump, but it is an air system, not liquid-based. You could work with it, but you'd need to fabricate a heat exchanger.

Click to expand...

Yup. A heat exchanger is already in the works, so it's no big deal, but still a bit disappointing for the first couple model years. Would technically need two separate heat exchangers for those if both heating and cooling were required!

The refrigerant in both variants is an HFC, meaning emptying and recharging the system for installation is necessary unless the heat exchanger can be bolted on (unlikely).

What are you trying to to do?

Oilpan4 said:

What are you trying to to do?

Click to expand...

This was just a final bit of fact-checking, see here: https://mynissanleaf.com/viewtopic.php?f=27&t=30503

I wouldn't.

More liberal use of the built in heater and a coating of AB foam would take care of most of the cold issues.
Just circulating some ambient air through the battery would be a massive improvement over the sealed box these cars come with now.

I would like to see a mod for some one to route the AC from the floor vent into or onto the battery. Not sure I would be willing to do it until I am off warranty, but even a mild help could do wonders for long distance summer travel.

Sub 50F travel the insulated battery is your friend.