Waste Heat

[meier]

I'm guessing by 'radiator' you're meaning the heater core?
Installing a Webasto is fairly easy - Lots of folks in cold climates have done this and the car is perfectly set up for it

http://myimiev.com/forum/viewtopic.php?f=14&t=1248

If you live where it's cold, there is very little 'waste heat' to be had from the motor cooling circuit - You're not gonna stay warm trying to get heat from there

Don

:-D yeah the heat exchange unit in the fansection ...


I will install a Webasto or a Eberspacher - I have seen all Ben's youtube videos and the ones from Stanislav Jaracz ...

I like the idea of mounting it under the car instead of the PTC .... but I still have some issues that im trying to figure out - fx I want the heater to start the fan also .. (i found a norwegian manual describing how to wire this)

But in the fall maby the excess heat from the engine could heat the car...

I found this info to how the dials actually works :

The way the heat works in the C-Zero (and all i-MiEV based cars) is that when you have the temperature knob on hot (or previously had it on hot before setting it to neutral) it will blast all the heat it gets from the heat exchanger. It will not mix any cold air into it. So you need to regulate the hot airflow with fan speed if you have a burner. The idea originally has been that the knob's heat setting directly controls the coolant target temperature of the car's own electric heater. If you turn the temperature knob to cold and either keep it there or turn to neutral without going on hot, it will only put out cold air into the cabin and no heat from the heat exchanger. Also the car's original coolant pump only runs when the knob is on the hot area. The burners I have also have their own pump, so they don't need that car's pump to be running, but it's something to keep in mind. I haven't had any problems with having two coolant pumps in the system running independently.

http://kwsaki.blogspot.dk/2016/01/heating-my-evs.html

 

[Don]

You can run the fan anytime you like, with neither the heat or the A/C selected. You can also select either outside air or recirculated inside air by pressing the button on the bottom knob.

The Webasto has it's own water pump, so you don't need to worry about the one in the car to move the water through the heater core - It will be fine even if the fan isn't running. I wouldn't worry too much about the fan automatically coming on with the Webasto either - When you first fire up the Webasto, the water will be cold and you really don't want to be automatically blowing cold air around in the car - Wait a few minutes and then select whatever fan speed you want

It's not a complicated install and it works very well - It's by far the biggest range extender you can buy if you live where it gets cold. I almost wish it was cold enough here for me to install one, but then we sometimes go all winter without the temperature getting below 32F, so it would be largely a waste to have one in our cars

Don

 

[PV1]

Airflow through the heater core depends on if the temperature knob is or was in the red or blue. If it is in the red or was in the red and is now on the green dot, air will flow through the heater core. If it is in the blue zone, or was in the blue and is now on the green dot, air bypasses the heater core.

 

[Anonymous]

PV1 do you or anybody have knowledge how to see the coolant temperature with info from the sensor on the MCU?
I wonder if Canion is able to shows this particular information from the coolant temperature.

Considering a start up test by only running the coolant from the motor through the heater core and return.
What's important in this case will be knowing the temperature and limits.
Hooking this up to a 12V valve passing the return coolant through the radiator when temperatures reaches higher than limit seams a safe solution.

Anybody with data on the coolant pump?
Amps:
Bar, pressure:

 

[PV1]

The data exists on the CANbus, but CaniOn's developers haven't yet utilized it.

I use my OVMS module and phone app to see MCU and motor temperatures. It's not perfectly realtime, but close enough for casual monitoring.

http://openvehicles.com

https://www.dropbox.com/s/lgk2a3hjfawb7ru/Screenshot_2015-11-07-20-00-11.png?dl=0

 

[Anonymous]

Ok. Thanks. Is this able to connect via ODB Link LX or is another ovms module required?


So I did a first stage rerouting to use the warmth from the power units. At this point the heated coolant is now passing through the heater core and returned, bypassing the radiator. Of course this need be monitored and upgraded before higher outdoor temperature returns.

The HVAC is not in use however ducting are rerouted so this still has got a loop from the HVAC to the coolant container at the front. This would allow QC charging without cooling function by the HVAC.

Coolant was topped up in both loops and checked for leaks.

The charger/motor cooling system and AC heater core are now in the same loop for testing.

After 1 hour charge and 15min city driving the fan was turned on to notice any warmth from the system.
Hardly any difference noticed at this point.
Longer trips, different driving and insulating the ducting could probably make a difference in terms of more heat generated.

 

[mdbuilder]

I would guess there is only around a thousand watts of heat available on average less whatever the airflow through the motor compartment takes away which might be considerable. Say 1/2 goes to the air, 500 watts remaining which is not much.

How'd I get that? 16 Kw in the battery, it would take about 1.5 hours of driving to use it up. That's an average draw of appr. 10,000 watts, figure 10% combined losses between the motor and controller = 1,000 watts waste heat.

 

[PV1]

Interesting. Try turning the recirculator on and running the fan on low. It takes a lot less to maintain temperature than to constantly heat outside air.

Thanks for jumping on this experiment. You may have saved me a lot of money and hassle if it doesn't work .

OVMS is a totally separate system, requiring the installation of two antennas and a small box that plugs into the OBD port. It more or less enables smartphone monitoring of the car's charge and location. At this time, it can't control anything on the car.

 

[Anonymous]

Field test on using heat from power units on AC.

Driven about an hours of mixed speeds using some 70% SoC. The more consistant motion and higer speed the more heat. I am guessing peak airstream temperature reached is 20degrees C when outside temperature about 10C and driving on highway (90-100km/h).
As stopping the car it was connected to evse and I went for a walk and getting cold.
Returning with cold hands (barely able to press the keys on the phone) to the car an hour an a half later
I put the key to "On" started the fan on step 2-3 of the AC and put my cold hands in front of the airstream. The airtemperature feels warm when the circulation pump is on and I am guessing around 8-10 degrees C over outside temperature. When the circulation stops the temperature slowly cools till a minute later when the pump is on again.

Would be interesting with actual temperature figures.

 

[Anonymous]

As the winter is arriving I am considering to improve the use of heat from the coolant system.

In order to do this I consider having a manual on-switch for the coolant pump.
Studying the diagrams of the car I learned there is a relay which activates the coolant pump and this be the coolant for the charging, mcu and motor. Anybody found where specifically this relay is located?

I'm considering a setup of separate insulated ducting from the coolant system routed in to the cabin.

I'm wondering if having a setup of two strings improves the heat exchange. One which is active when charging by routing the warmth from the charger directly to the cabin. This way bypassing the mcu and motor which currently functions as cooling ribbs - when charging only - with how I see it.
Second string on when driving will be the standard flow through charger, mcu and motor, though bypassing the standard radiator circuit and going through same insulated ducting to the cabin.

 

[kiev]

That relay is in one of relay boxes on either side of the 12v battery, depending upon RHD or LHD

 

[elekTrond]

Interesting topic this. I'm also pondering around this, and other heat stuff. But for now I'm doing the fossil heater upgrade, with a Binar 5S running on the devil's fuel... :twisted:

In order to do this I consider having a manual on-switch for the coolant pump.
Studying the diagrams of the car I learned there is a relay which activates the coolant pump and this be the coolant for the charging, mcu and motor. Anybody found where specifically this relay is located?

Oh, Dani boy, oh, Dani boy, oh boy, oh boy :lol: You must learn to master the MMC Manuals site. By looking in the workshopManual\70 -COMPONENT LOCATIONS\RELAY u'll find this:

Name Symbol/position
Water pump relay <LHD> B
Heater water pump relay A





PS! Someone should update the Tech ref subforum for rotten links, like this one: Mitsubishi Service & Maintenance Manuals

PPS! Oh well, I did report it - with correct URLs. :arrow: :mrgreen:

 

[Anonymous]

Status update on using the waste heat in the cabin as winter season is coming to an end.

Most heat is reused when the charger is working. Whether the AC charger while connected to evse or while driving and the DC charger charging the aux battery.

This has proven possible and pleasant if being in the situation PV1 described about being at an AC charger on a cold winter night on the way home. This solution offers a bit of heat in the cabin and clears the windscreen.

Heat from driving is minimal unless speeds at about 50miles/h - 90km/h or aggresive accelerations where the mcu and motor offers a bit of heat in to the cooling(heating) system.

This setup offers much less heat than the HV heater or fossile heater. However I found it is able to keep the windscreen clear durin rain and even de-ice when stationary connected to evse (charging) along with the fan on max on the A/C.

 

[jray3]

Thanks indeed. I've been enjoying the side effects of mounting a battery charger in the passenger compartment of JRAY's Golden Arrow (83 RX-7 conversion, PbA), which spent the winter outside. Charger heat keeps the windows clear on frosty mornings, and was even enough to melt up to 1" of snow overnight. It's enough to make me want to relocate other chargers!

 

[PV1]

Thanks for performing the mod and reporting back with results. I kind of figured that surface street driving wouldn't produce much heat, but highway driving would be where the mod is useful. A couple of years ago, I drove about 20 miles on the highway with outside temperatures below 20 F, and when I stopped at a convenience store, the temperature probe taped onto the coolant pipe coming out of the motor was reading 80 F with the cooling system un-modified.

Doing some testing over this winter, even one click of heat (heater temp about 90 F) kept the cabin warm enough to keep the chill out of the air. That was the main purpose of why I wanted to tap the coolant loop. But it sounds like unless one drives the highway a lot (I don't) or spends a lot of time at charging stations (which I usually don't), that this doesn't yield much thermal energy.

However, with the climate changing and the resulting trend of Pittsburgh winters getting more mild over the last few years, running the electric heater is becoming less necessary (it's either 10 F or 60 F outside).