Demist and winter range. - Renault Z.E. Forum
Reply
 
LinkBack Thread Tools
post #1 of 19 (permalink) Old 11-08-2013, 11:42 AM Thread Starter
Senior Member
 
Join Date: Jul 2013
Posts: 803
Demist and winter range.

OK, so today I ended up behind a smoking dinosaur juice-burning diesel that went to full-power in front of me. I hit recycle and avoided most of the cloud of stinking crap that came out the back of it, but, ah, the saintly aromas of the Fluence leather were tainted for a while!

Anyhow, the point I'm getting to is that I've realised that when the windscreen arrow is on alone and the recycle is on, then you do get both heating and air con at the same time. I'd rather presumed it'd not do this. I rather imagined some backward thinking greenie would programme the system to avoid such wanton energy waste.

Well, this is my typical operating mode in my Vectra for most of the time in heavy traffic - ac, heat and recycle - helps avoid keep the smelly world out of the car.

So I'm glad it does do this, even though I initially presumed otherwise. I also assume that this is a function that the Zoe can't do because it can't use the reverse cycle air con for both cooling and heating - or does it have two such systems?

But there are consequences! I aimed for 60~65 on the way home, which would normally draw ~2 octals, or a touch more, on warm days no HVAC. Using both recycle and AC drew that down to 3.5 octals. I know if I'd gone for the full 70mph then my 23 mile journey would've drawn a full half a battery.

Well, there it is. I'm glad that I can have both ac and heating, but it's then a 40~50 mile range.

Bear in mind we still appear to be using 100% batteries. They are 'only' guaranteed for 75% ... 30 mile range ... eek!
donald is offline  
Sponsored Links
Advertisement
 
post #2 of 19 (permalink) Old 11-10-2013, 04:05 AM
Banned
 
Join Date: Mar 2013
Posts: 167
RE: Demist and winter range.

I decided to allow myself a little heat yesterday for the run to the shops. Surprised to realise that the small amount of heat consumed more battery power than the 10 mile run. I'm glad to see the overnight frost failed to materialise or today's church run would have consumed even more! It makes me wonder how many kWh I consume on my 3 mile walk before breakfast exercising Max?
pauledg is offline  
post #3 of 19 (permalink) Old 11-10-2013, 05:25 AM Thread Starter
Senior Member
 
Join Date: Jul 2013
Posts: 803
RE: Demist and winter range.

Depends on your weight and speed of walking, but call it 500 kcal/hr == 0.6 kW.

donald is offline  
post #4 of 19 (permalink) Old 11-10-2013, 05:49 AM
Banned
 
Join Date: Mar 2013
Posts: 167
RE: Demist and winter range.

13.5 stone, short legs, 45-50 minutes, german shepherd trying to force into running. It certainly feels more tban 0.6kw
pauledg is offline  
post #5 of 19 (permalink) Old 11-10-2013, 06:04 AM Thread Starter
Senior Member
 
Join Date: Jul 2013
Posts: 803
RE: Demist and winter range.



Funnily enough, your brain and metabolism alone consume more energy than the actual walking.

You are actually only expending 100 W or so in very vigorous walking. A fit person can generate around 1 kWh for a hard days work at continuous high exercise levels. That's around 900 kcal of energy, but a typical 'man' needs to eat around 2,500 kcal worth of food.

So your 'mouth-to-feet' efficiency (fuel input versus achieved mileage) is around 10 M/kWh whereas your 'gauge' efficiency (energy used per mile) is around 50 M/kWh.

(The above is 'AFAIK' and if it transpires I've got any figures wrong then feel free to correct me!)
donald is offline  
post #6 of 19 (permalink) Old 11-11-2013, 12:50 PM
Banned
 
Join Date: Jul 2013
Posts: 381
RE: Demist and winter range.

Anybody done a demist from cold first thing on an icy morning? If one were only to charge the car once a week, is the normal demister quick without using the pre heat function? Not so bothered about how it affects range per se, but does it actually work and work quickly?
GrumpyCabbie is offline  
post #7 of 19 (permalink) Old 11-11-2013, 01:12 PM Thread Starter
Senior Member
 
Join Date: Jul 2013
Posts: 803
RE: Demist and winter range.

Not had a frozen screen yet, but on the basis of how fast it has been with a cold condensation-filled screen, I'd say it is pretty instantaneous. There again, having had an efficient diesel for so long that puts out zero heat for over 10 minutes, I would always pour warm water on the screen to help the thawing process, melt the wipers frozen to the screen (otherwise you can burn out the motors) and warm the screen up a little to avoid re-condensation.

(I keep a 4 or 6 pint milk bottle in the car, and go fill it up somewhere before heading for the car.)
donald is offline  
post #8 of 19 (permalink) Old 11-11-2013, 01:31 PM Thread Starter
Senior Member
 
Join Date: Jul 2013
Posts: 803
RE: Demist and winter range.

Had it plugged in overnight for a pre-heat in the morning, and drove off with the full demist/ac/recycle set. Nice dry warm car. Hustling along the motorway faster than I usually do also drew more than the usual juice.

I was thinking about this, and some views here, as I watched the gauge head beyond 3 octals used for 22 miles covered [=58 mile range - just as Renault suggests is the 'real world' usage in winter]. Pottering along in the summer I was managing to use a half of this amount of juice.

Halving your energy economy sounds (and feels!) pretty dismal, but I was thinking a little more and I guess I shouldn't feel so bad about it. After all, that would amount to an extra 40p for the trip which, if I were in my Vectra at 53mpg, would equate in cost to a drop from 53mpg to 48mpg.

In 'fuel-equivalent-cost' going from 2p/mile to 4p/mile is like going from 300mpg ot 150mpg. Relatively, sounds grim, but if I were in the Vectra and got 48mpg because it is a bit colder and the engine runs less efficiently, would I even notice?

I'm never going to burn up the motorway just because I have enough juice and for the sake of it because it makes so little difference to the drive time of my commute anyway. But I am not going to worry about keeping the heating on just as I like it so long as there's more than plenty of battery juice to get home. It's not an efficient thing to do, but forsaking 20p worth of juice and having an unpleasant environment to sit driving in is just daft.

Halving my energy economy from 2p/mile to 4p/mile? So what?!

donald is offline  
post #9 of 19 (permalink) Old 11-12-2013, 03:32 AM
Banned
 
Join Date: Mar 2013
Posts: 167
RE: Demist and winter range.

Yes, the academic study of Fluence figures is fascinating but to be honest the only one that matters is the available range in relation to your needs. I guess we all knew that driving an EV was going to involve some pretty sizeable compromises.

Our range anxiety will only be reduced once there is a uniform reliable working network of chargers without the nonsense of registering for their use and the current abysmal reliability record - for heavens sake many of these chargers have never been used yet so many don't work and cannot be relied upon.

Until that day - and what's wrong with a uniform acceptance of card payments at charge points - we will continue to hunt for any means of getting extended range. Leaf and Zoe owners who have the 80% in 30 minutes charge will still panic if the next available suitable charge point is duff - maybe more so as they will have at the back of their minds that they've got the problem sorted!
pauledg is offline  
post #10 of 19 (permalink) Old 11-12-2013, 05:51 AM
Member
 
Join Date: Aug 2013
Posts: 226
RE: Demist and winter range.

Quote:
Originally Posted by GrumpyCabbie
Anybody done a demist from cold first thing on an icy morning? If one were only to charge the car once a week, is the normal demister quick without using the pre heat function? Not so bothered about how it affects range per se, but does it actually work and work quickly?
Yep pretty quick. I did scrape the window as I am impatient. But I reckon no more than 5 mins for a completely frozen windscreen.
electricdream is offline  
Reply

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome