PREPARATION FOR COLD SEASONS

[sandange]

Yesterday I went ahead and did the heater insulation,

My hands are about the size of bear paws so....
I took my Miev to my local mechanic and had him put it up on the lift. He got in those tight spots to insulate the pipes and I assisted.

Cooked up a little bit different method, using a combination of several materials
the ingredients.....

http://s211.photobucket.com/user/Sandange/slideshow/miev/Miev heater Insulation

Heat resistant, Aluminum, silicone tape and EPDM insulating tape
A roll of aluminum foil,
2" Dow corning C 200 heat resistant foam board for the box perimeter,
Low expansion Expanding foam spray can (for doors and windows) heat rated specs, for bottom and sides of the insulating box.
1/2" & 3/4" pipe sleeve insulation for pipes
Tie wraps

Plastic cover removed and heater exposed

Pipes insulated, Ridged Foam pieces cut fitted to create a border dropping below the heater about 3/4"
Heater is tightly wrapped with foil & wires were wrapped with tape to prevent spray foam from sticking to it.

Foam injected around the top and surrounding edges to envelope the heater and bond the foam together

A piece of foam board was cut to the act as a bottom lid and then lined with foil.
Spray foam was applied to the bottom of the heater and piled up on the foam lid like whipping cream ,
The lid was lifted into place and held there with the help of a jack, & we waited for it to harden.
This created a molded bottom layer of insulation of about 3/4" thick .

Once the foam set (About 15 minutes) we removed the foam board lid, the excess foam was trimmed off and the aluminum foil stayed in place stuck to the spray foam. The extra foil that was hang on the sides was used to wrap up on the sides of the heater.

Finally the plastic cover was reinstalled.
It took about 3 hours to do the job on a lift

 

[evcar]

could you please post results? is this working? I mean in theory it keeps heat for longer time, but how in practice?

I have no insulation, factory heater and yesterday was some snow and -3 celcius (I can't operate Fahrenheit), and was pretty cold, heater almost to max + blower, lost 1/3 range.

I wonder what will happen in -20 to even -30 celcius degrees (january/februrary possible in Poland)

 

[Don]

I seriously doubt you could 'measure' any difference inside the car, temp wise . . . . unless it was 20 below and you ran the heater on max for 20 minutes and then did the same after the insulation job to see if you succeded in making the car a couple degrees warmer. On a 'normal' winter day, the heater should keep the car comfy (an opinionated term if ever there was one ) with or without the insulation job, so you probably wouldn't notice any real difference

What I think this insulation procedure actually does for you is to lower the number of watts it will take to keep the car at a comfy temp inside. Even if it only saves you 1Kw per hour, that's more juice you'll have to power the car down the road (and thereby you gain a little more range) and you'll benefit from that every time you drive the car with the heater on. It doesn't appear to be an expensive mod, so it's probably worthwhile for anyone who needs to use the heater much during the winter - I would go ahead and do it even if you can't 'prove' the exact amount of the benefit . . . . you KNOW it's helping

Don

 

[DonDakin]

I would love to know for sure how much this help but I agree with Don on this.

The only way to to get a really good comparison would be to compare two iMievs side by side (modded and stock) in a controlled environment and look at the power drain to keep the cars warm. Put the heater on full, measure interior temp and battery amps drawn. It would be best to do this in an open parking lot with a good stiff 50+ km/hour wind to simulate driving. If someone in the Montreal area wants to do an experiment we could try but I think it would be difficult to set up. If we try this experiment driving side by side the driving variations would add too much variability. Probably not going to happen in either case but who knows.

All that to say its difficult to measure this improvement. That being said I did a rough calculation and came up with about 750 watts of heat loss in the heater itself in cold moving air at speed about 50 KM/hour.

So in 2 hours you would save 1.5 KWH or about 10 km in range. Not tons but something. About 10% of the cars range.

Like Don said this is a really cheap DIY mod that common sense tells us will do some good. So if your motivated, go have some fun with insulation....

Don......

 

[Don]

My limited use of the heater has been somewhat eye opening for me

As someone who is used to the virtually unlimited heat produced by an ICE powered cars heating system, the amount of heat that our 5 KW unit produces pales by comparison - I had expected their heat output would be . . . . similar - Nope!

When you consider that only a small portion of the ICE's 'waste heat' is being utilized by the cars heater system (the radiator is still doing the lions share of cooling the system) you begin to realize how much of the energy in a gallon of gasoline is wasted generating unneeded heat. It would be interesting to know what percentage of the energy in a gallon of gasoline is actually used to move the car - I'm sure that percentage for an EV is double or more . . . .

[Edit] - I did some searching. The results are astounding. " . . . . of the 130 million joules of chemical energy in the average gallon of gasoline, only 19.5 million are converted into the kind of kinetic energy that matters—forward motion of the car. The rest are literally disappearing into thin air"

So a typical ICE is around 15% efficient - The other 85% is more or less . . . . wasted. Hybrids are no doubt a little better, as (like us) they don't waste anything idling while the car is stopped

Interesting reading here - http://www.beyond-the-edge.com/automotive/eliminating-the-wasted-energy-in-your-car/

"If you had to invent an efficient way to move a person from one place to another, you could hardly do worse than the modern automobile. After more than a century of refinement, even the most over-engineered slab of German perfection wastes 85 percent of the energy in the fuel we put into it."

Don

 

[MLucas]

It's all very abysmal when you think about how much energy is wasted. Driving our EV's is like taking two gas cars off the road for what we expend in forward motion.

I have yet to experience really cold temperatures with the i-MiEV but so far the heater is working just fine for the temps I'm experiencing (5 - 15 celcius). I usually put the heater at the first or second notch and keep plenty warm and using the seat heat a lot. I'll have to see how colder temperatures work over the heating system.

 

[jaraczs]

Hey friends,
Thank you very much for sharing your modifications. Although NJ is not as cold as Canada, I also decided to insulate the heating system, at least. I have done this over a few days with simple garage jack so, I had to work in very congested space.
Only a portion of the plastic cover was removed (4 screws and 1 plastic clip). In order to remove the clip, the center insert has to be first removed carefully, e.g. with two flat screwdrivers. The heater was wrapped with Frost King brand 2" duct insulation (foil and fiberglass, R6) from Home Depot and it was secured in place with regular tape.

The pipes consumed over 9 feet (~2.8 m) of Armaflex foam and because the self-adhesive did not stick at bends, regular tape was used to keep the foam around the pipes. And yes, the space is very tight around those hoses. The left (driver) splash shield had to be partially removed to gain access to the pump. In order to loosen the splash shield, several plastic clips had to be removed, where the center inserts can be taken off with phillips screwdriver.

 

[jaraczs]

It looks like the heating system was taken from the gas version where the pipes were coming from the rear engine, so they cut the lines in the center where they added the heater. If the insulation helps to boost efficiency in winter, and I am certain it will, the RR with heater on should be constantly underestimated because it is calibrated based on un-insulated heater. Do you guys observe this?

Another take-away. The heating system contains 1.9 L (1/2 gallon) of fluid and it takes some time to get the heat into the cabin because we need to heat the fluid, first. Unfortunately, the heat cannot be fully utilized because the moment you turn off the heater, the water pump stops too and the hot liquid is not taken through the heating core to exchange the heat with the cabin air.

I have found interesting article on ceramic heaters for EVs. It is old (and quite lengthy) but it all makes sense:
http://www.evsource.com/articles/heater_compare.php

In short, the heater core in the cabin (under dash) could be replaced with 2 ceramic heating elements (taken from $20 small space heater, 2 x 1500W) and powered from original heater power line. The warming effect would be much faster as there is no liquid to heat, just direct air heating. Further, because of no heat loss in the pipes, those 3000W could be just enough. And, it would save some weight. Such a modification would be irreversible and as such I am not going to venture into it until after the warranty.
However, should anyone decide to explore it further, I am listening ...

 

[Don]

If the insulation helps to boost efficiency in winter, and I am certain it will, the RR with heater on should be constantly underestimated because it is calibrated based on un-insulated heater. Do you guys observe this?

The RR 'guess-o-meter' should be just as accurate with the heating system insulated as it was without because the number displayed is calculated based on how much energy you've actually been using for the past 12 or 15 miles - If the insulation really is causing you to use a bit less, the RR meter already knows that and has used that fact to make it's calculations

Another take-away. The heating system contains 1.9 L (1/2 gallon) of fluid and it takes some time to get the heat into the cabin because we need to heat the fluid, first. Unfortunately, the heat cannot be fully utilized because the moment you turn off the heater, the water pump stops too and the hot liquid is not taken through the heating core to exchange the heat with the cabin air.

The temp control turns the heating element on and off as needed - If it's set just one click above center, the pump runs all the time and the element cycles on and off as needed to give you just a little heat . . . . you never have 'hot' liquid, just lukewarm but you're taking advantage of whatever heat the element produces

In short, the heater core in the cabin (under dash) could be replaced with 2 ceramic heating elements (taken from $20 small space heater, 2 x 1500W) and powered from original heater power line. The warming effect would be much faster as there is no liquid to heat, just direct air heating. Further, because of no heat loss in the pipes, those 3000W could be just enough.

Since the power source is 330 volts, I think you'd need to use 3 of the ceramic elements wired in series . . . . they would probably draw a little less than 1500 watts each since they'd be running on 110 volts or less. It doesn't really matter if you have 3000 watts of heat or the 5000 watts that the water heating element in the car uses as the temp selector will still cycle it on and off as needed - If it's more efficient heating air than water, it would use less power regardless of the element size

One of the things that Mitsu is busy working on for the next version of the car is a more efficient climate control system - A/C and heat both, but especially the heating system

Don

 

[jaraczs]

The RR 'guess-o-meter' should be just as accurate with the heating system insulated as it was without because the number displayed is calculated based on how much energy you've actually been using for the past 12 or 15 miles - If the insulation really is causing you to use a bit less, the RR meter already knows that and has used that fact to make it's calculations

Don,
The guess-o-meter has two levels, with and without heater on. When you turn on the heater, it automatically drops RR by 1/3 (I think) depending on the fan speed because it is factoring-in the consumption of un-insulated heater. This is why I think the calculated RR should be lower than the real available range after insulation.
Sandage, Lowracer - any word on this one?
Thanks, Stan

. . . . you never have 'hot' liquid, just lukewarm but you're taking advantage of whatever heat the element produces

OK, it is just lukewarm. I don't want to give up even this energy. I would rather have the option to turn off the heater some 5 minutes before arrival and keep the pump on to transfer all the heat inside.

 

[jaraczs]

The guess-o-meter has two levels, with and without heater on. When you turn on the heater, it automatically drops RR by 1/3 (I think) depending on the fan speed because it is factoring-in the consumption of un-insulated heater. This is why I think the calculated RR should be lower than the real available range after insulation.

...unless the guess-o-meter has the ability to learn that the heating system from some reason uses less power. Then it should be accurate. That would be true. Perhaps the initial 1/3 RR drop is based on default value and then it starts estimating based on real power use.

 

[JoeS]

Last time we had a discussion on this it seems that the RR took about a 15%-20% hit, although it was nebulous enough that it would probably be difficult to discern more accurately. I have faith in our RR algorithm (don't insult it by using the notorious Leaf guess-o-meter GOM acronym) that it will compensate and self-correct once it determines the changed consumption/km.

 

[sandange]

Started cooling off -

This morning temps were -8 c ( 17.5 F ) at 6:30 am , when I got back from a 1 hour drive to drop my wife off at the train station.
The forecast high 6 c ( 43 F ) for today

My experience at this temperature -
Car was parked outside overnight, plugged to level 2 charger, & has 11,651 km ( 7,240 miles ) to date.
Pre heated the car for about 12 minutes on defrost before leaving at 5:40 am

Ran the heater 3 notches into the red and the fan speed at about 5/8 speed (1/2 defrost and 1/2 heat)
Did not use the seat warmer
Dressed with lined boots and wore winter jacket & light woolen gloves , perfectly warm and comfortable

Started off fully charged
With the heater on the RR gauge was showing 94 km ( 58.4 miles ) at departure.

Traveled 36 km ( 22.4 miles ) with the heater on.

At the end of the trip RR gauge was showing 56 km ( 34.8 miles ) with the heater on.

Total real distance traveled 36 km ( 22.4 miles )
RR gauge km / miles drop for the trip 38 km ( 23.6 miles )

No Noticeable difference in the cars performance

All is good so far

Tomorrows forecast high 0 c and low overnight -12 c

 

[nt2w]

I've been tracking the RR meter's morning "fully charged" reading since September to follow it over the winter season and see if there's any decrease as the thermometer drops.

Since I started using the heater regularly (right around Hallowe'en), I've been recording both the RR without heat and RR once the heat is on.

Observations so far:

First off, the RR meter doesn't seem to change based on the setpoint of the heat (i.e, what point in the "red zone" the temperature is set), but does change based on the fan setting. I'm trying to think of the reason for this- one explanation could be that the ceramic heater heats the fluid to the same temperature regardless of the heat setting, but the RR indicator figures more heat will be removed from the fluid with higher fan speed, requiring the heater to cycle more. Setting the temperature to a lower level might not lower the temperature of the fluid in the system, but only reduce the flow into the inside-the-car part of the circuit... not sure how that works. Just a curious effect.

As far as range, it appears that my fully charged RR has dropped from an average of 75 miles to an average of 63. The "heat on" (temperature at full "hot," fan about 2/3) range has averaged 52 miles. I need to have more time to get more confidence in the data- some of the impact could be different driving requirements over the short period with heat. However, I think the data so far may be valid. It's currently 27F as I'm writing this, we'll see what things look like deeper into the winter when 27 will be "warm!"

Cheers-
Rich

 

[tonymil]

As far as fan affecting RR but not heater setting, I think going from no heat to heat is a big jump in battery usage, whereas moving the temperature from low to high results in a very small increase. But the fan speed cools the heater substantially, moving the hot air away from the heater requires the heater to work harder/consume more battery. It isn't that the fan consumes much energy, its that the fan moves the heat away from the heater making the heater work harder. Well, that's my theory.

 

[JoeS]

... it appears that my fully charged RR has dropped from an average of 75 miles to an average of 63

Hi Rich, this corroborates the initial speculation of a 15%-20% RR drop with heater, and I think those of you in colder climes will have fun over the next few months exploring the subtleties of our heating system and perhaps pinning down the exact cause/effect and impact magnitude. Incidentally, the seat heater doesn't seem to be enough load to take a RR hit. Sandange, thank you for keeping track of the numbers ... and winter is only beginning. I'll be curious how you'll be rating the iMiEV's snow-handling capabilities.

 

[Don]

First off, the RR meter doesn't seem to change based on the setpoint of the heat (i.e, what point in the "red zone" the temperature is set), but does change based on the fan setting. I'm trying to think of the reason for this- one explanation could be that the ceramic heater heats the fluid to the same temperature regardless of the heat setting, but the RR indicator figures more heat will be removed from the fluid with higher fan speed, requiring the heater to cycle more. Setting the temperature to a lower level might not lower the temperature of the fluid in the system, but only reduce the flow into the inside-the-car part of the circuit... not sure how that works. Just a curious effect.

I *think* that's because the heat is 'full on' until the car's inside temp reaches the temp setpoint on the dial no matter how far into the red you have it set - If and when the car's interior ever gets warmed to the actual setpoint, the RR display would likely give you back some of the 20% hit it took when you turned the heater on . . . . at least my experience using the A/C every day all summer leads me to think so

The fan speed has a greater effect than the temp select does on the RR display using the A/C also

Don

 

[MLucas]

First off, the RR meter doesn't seem to change based on the setpoint of the heat (i.e, what point in the "red zone" the temperature is set), but does change based on the fan setting. I'm trying to think of the reason for this- one explanation could be that the ceramic heater heats the fluid to the same temperature regardless of the heat setting, but the RR indicator figures more heat will be removed from the fluid with higher fan speed, requiring the heater to cycle more. Setting the temperature to a lower level might not lower the temperature of the fluid in the system, but only reduce the flow into the inside-the-car part of the circuit... not sure how that works. Just a curious effect.

I *think* that's because the heat is 'full on' until the car's inside temp reaches the temp setpoint on the dial no matter how far into the red you have it set - If and when the car's interior ever gets warmed to the actual setpoint, the RR display would likely give you back some of the 20% hit it took when you turned the heater on . . . . at least my experience using the A/C every day all summer leads me to think so

The fan speed has a greater effect than the temp select does on the RR display using the A/C also

Don

I've also seen a 'give-back' on the RR when I set both of the lower dials (fan speed and air flow) to AUTO.

 

[RobbW]

Okay, I'm going to revive an old thread and NOT apologize for doing so! While it is still technically summer, we have been experience more fall-like weather and temperatures here in the Chicagoland area the past couple weeks. This has gotten me thinking about the upcoming cold weather that is only a couple months away now. I am concerned about the automatic range reduction associated with using the heat in our i-MiEVs. Since my employer will not allow me to plug in while at work, I want to plan ahead and make sure I will have plenty of range to complete my daily round-trip commuting cycle of around 40-50 miles.

I have been reading through this thread and others to get tips on extending range during cold weather. Seems like the most common suggestions are to pre-heat the i while it is plugged in during the morning, keep the heat on auto and/or low settings, and use the driver's seat heater almost exclusively if possible. This is all well and good if you are driving by yourself. However, my wife and kids will not be happy with these miserly attempts at extending my range, especially since none of them are afforded the comfort of seat heaters.

For those of you who have now gone through a full winter cycle with your i-MiEVs (especially those who experience significantly cold winters), would you mind answering/addressing my questions below?

1). First, with regards to the meat of this entire thread, what has everyone's experience been with insulating your heaters, hoses, doors, etc.? Since the last post in this thread was back in November 2012, we haven't received any reports on your results during the extremely cold portions of the deep winter. Did all the insulation mods help? How much of an impact or effect did it have on your RR? Is there anyone here who has had their i through two winters now and performed any insulation mods for the second winter? What differences did you notice from the first winter without insulation to the second winter with insulation? Were the benefits significant or just slightly marginal? Worth the time, effort, and expense to insulate?

2). I want to be confident that I will be able to continue driving my i (and saving on fuel costs) this coming winter. What should I expect in a worst-case scenario? The worst-case scenario being the following:

a. Middle of January and daily high temperature is only 5°F for an extended period of time (1 week or so) possibly dipping below 0°F.
b. Round-trip daily commute of 40-50 miles.
c. No ability to opportunity charge while at work for 9 hours.
d. Car will sit parked outside in the frigid cold unprotected from the elements for the entire 9 hours.
e. For the full, maximum comfort of any/all occupants, the heat will be on full blast/full fan for the entire trip both directions.
f. Being an idiot, I forget to preheat my i in the morning while it is plugged in.

Given these worst-case conditions, should I still be able to complete my entire daily commute? Will I be able to complete my commute with plenty of RR to spare? Will I be cutting it pretty close? Or is there no way I could complete my round-trip without plugging in at work? Perhaps the recommended action would be to not even attempt my commute in the i-MiEV during the worst parts of winter and just use my ICE?

Of course, these are worst-case conditions. The most-likely scenario is that I will definitely preheat my i in the morning while it is plugged in to L2 EVSE. I will only have passengers with me for the first 3-4 miles of the 15-mile one-way commute. So, I will be able to take the heater off of full blast/full fan once I have dropped everyone off at their respective destinations. While my employer will not allow me to plug in at work on a regular basis, I was told that if there is ever an emergency and I NEED to recharge, accommodations can be made in those (implied) rare situations. In January, the average temperatures in my area are a high of 30°F and a low of 13°F. The record low in January is -27°F.

I guess my biggest concern about winter driving in the i-MiEV is the consequence of my car being parked outside unprotected in extremely cold temperatures for up to 9 hours at a time. For those who of you who now have at least one winter season under your belt, what has your experience been?

 

[jray3]

Ouch Robb, winter talk, but no worries- you ain't bringing me down as Seattle enters it's crescendo weekend of summer!

That situation at work is a bummer. Every negotiation is different, but when some members of management at my employer expressed concern about my plugging in, I trailered in a genset and left it running for four hours while I recharged, parallel parked on a public street at the front curb. My boss gave good chuckle over that, and nary a word of objection has been heard since! :twisted:

Sounds like your i is garaged, so the pack can recover temperature overnight, but will become a cold slab by end of shift...

I have no results to report, but intend to experiment with the following this winter:

• a radiant heating panel on the garage floor, to keep pack temp around 65 degrees
  insulation of the heater and hoses as described by others,
  using a new nearby Blink station for pre-heat before my homebound commute