Climate Control Solution - Gain Control of your Heater!

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jclemens said:
There is a little vent under the start button, that is where the sensor is. If/When i get a 12v heater, i was going to try this, but please post your result here if you can get it to avoid turning on the main heat.

edatoakrun said:
Even simpler. The next cold and wet day, I'll try using my 12 V accessory heater. It should be able to heat up that area above 60 degrees, to "fool" the sensor, quite easily.

Could you more precisely state the sensor location(s?), for those without the service manual?
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Well this guy never replied, since then, I got my own 12V mini-heater and yes, when you warm up the sensor, the main heat shuts down.
This implies that the heat can be controlled by a simple switch and resistor wired into the sensor to spoof the system into thinking the car is warmer than it actually is.

Forcing the defrost fan to recirculate instead of taking air from the outside is another matter however, and it runs a chance of creating more fog if it blows moist warm air onto a cold window.

It is possible, but we would have to not only re-wire the air valves, but the sensors that indicate the position as well. Probably not worth the effort.
 
Well, if you check the service manual, it describes how the sensor works and what resistance values it has.
(see posts on previous page of this thread for which page)

resistance goes down as the temperature increases.

The best way would be to put a resistor in parallel to lower the resistance of the sensor, and then have a switch in series with the resistor to enable or disable it. You could even use a potentiometer to adjust the spoofed temperature to control if/when the heat comes on. Chart# JPIIA1862GB has the data on the in-vehicle sensor (in HAC section)

I thought about using a switch to completely disable the sensor while switching over to a fixed resistor to spoof a fake temperature, but if the climate control was set to a higher temperature, it would stay on maximum and may not turn off until the input temperature is manually set to a lower number. You'll want to keep the sensor in the circuit at all times, (even when the switch is momentarily between contacts when switching, but not an issue if using a simple open/close SPDT switch)
 
Please keep us posted. I for one are very interested in trying something like this since apparently the new chip that was supposed to fix it all fell through, or at least I assume so since nothing has been said for weeks.
 
I live in South Florida where we have had cool weather lately (down into the low to mid-seventies). However, it is too warm to drive around with the windows up, and the noise is too much when I am on the interstate. I wish I could run the fan only to get outside air, but that starts the climate control drain on the mileage, even if I turn off the "auto" mode and do not turn on the air conditioner. Is there any way to just get the fan to run without the climate control kicking-in automatically? :?:
 
TonyWilliams said:
N1ghtrider said:
Is there any way to just get the fan to run without the climate control kicking-in automatically? :?:
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No
Click to expand...

Yes - most times. Just turn the temp setting down to 60 and leave it there. Then you can turn the fan on. Make sure the auto and A/C lights are off. The climate control (heater) will not come on unless it's so cold outside that the inside of the car is less than 60. The A/C will probably come on when you turn the fan on. Just turn it off, no problem.
 
the mode foot to vent works OK if there is only one person in the car and the need is slight, but with four I am forced to turn on the fan and that brings the climate control on. I had hoped the new software upgrade would address this problem, but it doesn't. What is the status on the kit to give control back to the user.
 
Looks like I'll be able to Demo the upgrade at next weekend's BayLEAFs meeting in San Francisco. I should also be able to offer upgrades to a few people that want to become the first to receive it. (I can assist with the installation after the meeting if you like.)

-Phil
 
Do we have a price yet? What is involved in the install?

Ingineer said:
Looks like I'll be able to Demo the upgrade at next weekend's BayLEAFs meeting in San Francisco. I should also be able to offer upgrades to a few people that want to become the first to receive it. (I can assist with the installation after the meeting if you like.)

-Phil
Click to expand...
 
Ingineer said:
The final version of the upgrade differs a little from the prototype, you will now NOT have heater operation, regardless of set temperature / car temperature, unless at least one of these is true:

1. A/C button is illuminated.
2. Rear Defroster is on.
3. Climate Control timer engages.

I found that controlling the heater with the A/C button is the best and most intuitive.
Click to expand...
Sounds great, but (sorry!) - one known issue is that the heater will come on with the A/C when the system isn't working hard to cool. You can see this typically when ambient temps are 65-75* and the interior of the car has cooled off already. HVAC will register 500-750W or so, but if you drop the temperature a degree you will actually see power draw go down.

I presume that this is done to help dehumidify the air, so humidity levels probably play a role here as well.

It doesn't sound like there's a way to keep the heater from coming on in this situation where you want a small amount of A/C but no extra dehumidification with your mod? Am I missing something?
 
drees said:
Sounds great, but (sorry!) - one known issue is that the heater will come on with the A/C when the system isn't working hard to cool. You can see this typically when ambient temps are 65-75* and the interior of the car has cooled off already. HVAC will register 500-750W or so, but if you drop the temperature a degree you will actually see power draw go down.

I presume that this is done to help dehumidify the air, so humidity levels probably play a role here as well.

It doesn't sound like there's a way to keep the heater from coming on in this situation where you want a small amount of A/C but no extra dehumidification with your mod? Am I missing something?
Click to expand...
Yes, I did not see this happen as you say when I had the Leaf fully instrumented. It will sometimes run the A/C for dehumidification when the heat (especially for defog) is on, but I've *never* seen it run the heater when the A/C is called for! I had instrumentation in the car to tell me the current heater PWM values, and I did not see this. I suspect for whatever reason, this is actually just the A/C running at a low idle to keep the system's high side/low side pressures at their optimum balance to ensure the expansion valve is doing the most efficient transfer. Disturbing the temperature may make the system back off for a bit to reset the algorithms. If you can come up with an exact and reproducible set of test parameters, I'll be happy to test it both the PTC duty cycle as well as the compressors and see if I can confirm it. Maybe it's due to our fair Bay Area weather here!

If I am somehow wrong and this turns out to be true, and you simply can't tolerate the heater, the "fix" is to just turn the A/C off for a bit until the delta T is a bit larger and then turn it back on. Or, if you that concerned about the power, you probably don't want anything using extra power!

If you can propose a better way to implement this without needing to drill holes and add switches, I'm all ears!

-Phil
 
Definitely interested in this upgrade; I wish I lived close enough to be one of your first guinea pigs! I agree that the AC button is an intuitive choice for the main heater control and have often wished that pushing it would knock out the heater as well as AC.

Thanks to preheating and the steering wheel/seat heaters, I am finding that I almost never need the cabin heater while driving save for occasional defogging (and that could likely be accomplished if I could just blow unheated air on the windshield/side windows).
 
dgpcolorado said:
Definitely interested in this upgrade; I wish I lived close enough to be one of your first guinea pigs! I agree that the AC button is an intuitive choice for the main heater control and have often wished that pushing it would knock out the heater as well as AC.

Thanks to preheating and the steering wheel/seat heaters, I am finding that I almost never need the cabin heater while driving save for occasional defogging (and that could likely be accomplished if I could just blow unheated air on the windshield/side windows).
Click to expand...
I did a DIY install of seat heaters in my 2011, and I too find that most of the time I can get by by with the A/C button off, but I like a little fresh air on my face. I like that I can adjust the fan and don't have to worry about anything turning on I don't authorize. Wish I could easily add that wheel heater though! :mrgreen:

-Phil
 
Neat idea, I like how simple and inexpensive it is. One issue I've had when precooling on a mild day is even though it's sunny out and warm my garage can stay cool from the night before and so the precool will actually cause the heat to run. Is there any good way to control that?
 

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