Easy Climate Control Fan-Only Solution - 5 cents, 5 mins

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hyperlexis said:
I can't understand this. Why in the world is there no 'ram-air' system were one can jut get flow-through air from the dash vents without running the fan at all
It's there right now! Turn off the CC, make sure flow-through is on and press Mode until you get dash air. I use it often.
 
chortle said:
Let me have that same system for the heater, run for a few minutes, off for a few minutes.
Just build a small dial resister and switch with a 555 timer into the power circuit.
Is it that easy or am I missing a whole bunch of important stuff?
Bill Matley

Yes, that would work if that is what you want. You can connect the output of the NE555 directly to the gate of the MOSFET.

I'm not sure if it will actually save you a lot of energy because the PTC heaters in the Leaf heat up water to around 160F. So as we all know, it takes a while until you will get usable heat in the interior. During the off periods the water cools down again, so on the next on-cycle you need to put in more energy than if it would have been running continuously.

BTW have you seen the picture I took of the hot water pipes in the engine compartment? The insulation is a joke with parts of it completely exposed. It really dates back to the ICE age where heat can be wasted.

When I find the time I will add some more insulation. That should improve the efficiency of the heating system. It should also improve the effectiveness of your idea.
 
This is awesome!! Thanks so much for posting this, I have been planning for some time to put a switch on the cabin temperature sensor for some time, but I havn't gotten around to it. I am so glad there is another circuit bender who is willing to share information here! I'd bet you are the type to upgrade your own EVSE (or build openEVSE)
 
BetterLeaf said:
camasleaf said:
I would also be interested in being able to run defog in recirculation, I realy miss having this option.

I've just tested that. It works in my Leaf. With defog on, I can still switch between fresh air and recirculation.


That is strange, whenever I am on any mode that has anything to do with defog, it will not let me chose re-circulation, i have to change the mode away from defog for the button to work. If I switch mode to defog ( or feet+windshield), it forces the re-circulation to switch to fresh air. Did you do a different mod?
 
FYI folks, not all CC units are the same in all countries and in all model year US cars, there are multiple units. I would caution folks not to assume this is the same as Phil's modification and that there can be functional differences between units that are not evident. Even if this works on some US cars it does not mean that it wil not impact some aspects of the system. Phil goes to great lengths to test his modifications under many conditions and variables not just "it worked for me". Messing with various aspects of the car because it seems to work on one car can result in some regretful mistakes. Adding fog light and doing horn mods is one thing but these complex modifications require testing of other related systems. The CC circuit board is also quite intricate and can easily be damaged.
 
i turn on the fan without the heater by doing this.
press auto
press AC to turn it off
adjust fan as desired

heater is not on.
 
thankyouOB said:
i turn on the fan without the heater by doing this.
press auto
press AC to turn it off
adjust fan as desired

heater is not on.
Dude, you live in LA. ;)
If it's 50° F or lower, the heater starts up if you have the fan on at all, even with the temperature setting at the lowest (60°).
 
garsh said:
thankyouOB said:
i turn on the fan without the heater by doing this.
press auto
press AC to turn it off
adjust fan as desired

heater is not on.
Dude, you live in LA. ;)
If it's 50° F or lower, the heater starts up if you have the fan on at all, even with the temperature setting at the lowest (60°).

ha!
oh, you mean it starts up when you need heat?
---
Yea, garsh, i getcha. you are in a range battle (choose between heat and getting home). we forget that a hoodie isnt a winter coat all around the country.
 
thankyouOB said:
garsh said:
thankyouOB said:
i turn on the fan without the heater by doing this.
press auto
press AC to turn it off
adjust fan as desired

heater is not on.
Dude, you live in LA. ;)
If it's 50° F or lower, the heater starts up if you have the fan on at all, even with the temperature setting at the lowest (60°).

ha!
oh, you mean it starts up when you need heat?

I had a car full of people the other day. It was a chilly and sunny 45 degrees that morning. After we ate brunch out we walked back to the car, which had been sitting in the sun for a few hours. Outside temp was still around 45 and the cars inside temp was well above 70 because it had been sitting in the sun. I turned Mode to blow air without Auto/AC on and temp set to lowest level of 60... even with no lights illuminated, the car still fired up the heater - I presume to get the outside temp up to 60 degrees before having it enter the cabin.

I want to do the deluxe version but need to find someone who had the experience. I really appreciate the writeup - thanks!
 
aminorjourney said:
Can I just check if there are any particular power ratings on the components you've listed? Any specific wattage of resistor?

thinking its just signal voltage so pretty small one would probably do. i notice the range is pretty large i am guessing to compensate for ambient temperature differences?
 
This is a clever idea that I would never thought of. Since I have no mosfet's on hand I used a CD4016B CMOS IC.

Everyone that builds things has their own preferred method of construction but to me space wiring is like fingernails on a blackboard! I mounted the circuit on a small vector board. It seems to work really well and it cost me nothing. Even buying the parts would be well under five dollars.

heatermod_zps333570a1.jpg
 
EricBayArea, I first built the circuit using an NTE490. The unit did nothing! Over the years I have found NTE is hit or miss. I have no doubt it world work fine with the proper part but I just decided to use the other approach.
 
DaveinOlyWA said:
Very interesting. Can you post pix of these pipes? Sound like an ready step most of us can take easily

If you look at the two pictures that I posted at the beginning of this thread you can see the pipes. On the second one you can see the non-existent insulation.
I will try to post better pictures shortly.
 
jclemens said:
This is awesome!! Thanks so much for posting this, I have been planning for some time to put a switch on the cabin temperature sensor for some time, but I havn't gotten around to it. I am so glad there is another circuit bender who is willing to share information here! I'd bet you are the type to upgrade your own EVSE (or build openEVSE)

Thanks and yes I've designed and built two different low cost EVSE. More on that later. :)
 
aminorjourney said:
Can I just check if there are any particular power ratings on the components you've listed? Any specific wattage of resistor?

The one with the "highest" power will be R1 here 1/8 of a watt will do. The rest can be almost anything.
 
I did a quick experiment. Preheated the car for about 10 mins. Outside temp was around 26F.

Here are some pictures that I took with a thermal imaging camera. All from the driver's side perspective.

30kpwfb.jpg


Upper left shows the center vents where the warm air blows out at about 91F. (You can also see the heated steering wheel)

The other pictures show the engine compartment.

Upper right shows the primary hot spot. That's the junction where the heater fluid sensor is located. No insulation!
You can also see the "quality" of the insulation that reduces the temp by about 17F. OK, it is better than nothing.

Bottom left picture follows the pipe where the sensor is to the left. It focuses next to the clip where the two pipes are held in place.

Bottom right shows the heater fluid tank close to the drivers side head lamp. In blue you can see the cap. It shows the temps in degree Celsius but with 100F it is just as hot as the sensor location.

Here are some regular photos that show the approximate angle the thermal images.


4hzc5t.jpg


volug8.jpg


I have not had enough time to double-check this but from the service manual and initial inspection the flow of heater fluid passes through the heater electric water pump, PTC element heater, heater fluid sensor, heater core which warms the air, heater fluid tank and then returns to the heater electric water pump.

OK, that's it. I don't know about you but I feel the sudden urge to visit my favorite hardware store.
 
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