Electric cars, does everyone really think they are amazing.
Discussion
blearyeyedboy said:
Forgive the off topic discussion, but this just isn't true.
Don't take my word for it; google how to make text more readable.
As for pumps, of course you pump heat from an area of low concentration to an area of high concentration. That's the whole point. You don't need pumps to go down a heat gradient: That's called Opening The Doors And Windows In Winter. It's been 20 years since I did A level physics and even I know you're not right on that score.
Heat pumps are just not efficient though. Like I've said I've worked for a firm that would have had me sell them. The customer was promised a heat pump that used less than 3kw but would heat the whole house. Customers suffered from luke warm radiators and I'm talking to the point of you can hardly tell by touching the radiators if the heating is on or off. If heat pumps were really 3x more efficient than other forms of heating per kw we would expect this to be near sufficient to keep the radiators hot ad the house warm but this was not the case. However, stick the evaporator of a heat pump in a warm spring and I'm sure the houses would have been toasty and the heat pump worthwhile. Don't take my word for it; google how to make text more readable.
As for pumps, of course you pump heat from an area of low concentration to an area of high concentration. That's the whole point. You don't need pumps to go down a heat gradient: That's called Opening The Doors And Windows In Winter. It's been 20 years since I did A level physics and even I know you're not right on that score.
The evaporator of an EV heat pump is in an area at atmosphere temperature, this is not a hot spring. If the EV heat pump system draws one kilowatt, even if the heat pump was 3x more efficient than a resistive heater (which it certainly is not despite any hype or theories that don't touch enough on ineffiiiencies) the EV would still only have a 3kw heater. An ice heater is capable of delivering much more than 3kw of heat, can deliver 3kw of heat after only a minute's engine warming time in winter and using the ice heater does not affect range at all. An accurate informed guess of how running an EVs 1kw heater/AC unit will affect range can be seen in one of my recent posts above and is far from impressive.
Edited by SimonYorkshire on Monday 23 October 21:57
Evanivitch said:
How is using 1kW of electrical energy to move 3kW of thermal energy not efficient?
It turns out you don't get the 3kw of thermal energy. Put it like this, if shifting/pumping heat were 100% efficient then with less than 1w of power we could make a place that was at 273 deg K o deg K but we can't. If shifting heat were 100% efficient we could use less than 1w of power to make an area outside our houses -20c but heat the inside to 23c but we can't. Where do you think the '3x; comes from, and how accurate do you think it is, and are you so sure about this that you too have bought a heat pump to heat your house?
Or is it more of an EV manufacturers sensible (if you like, even I say) idea of employing kit they would fit to the EV anyway (AC) to serve the dual purpose and thereby minimise parts that they need to fit to effect the heating facility. I know the answer, it is obvious. And another obvious point is that you wouldn't find such a setup on an ice car, firstly because there is an even easier and even free way to get heat, from wasted engine heat, and secondly because ice cars have such a reserve of range and power they can afford to run both AC and heating at the same time. This is a negative for EVs, because they could run AC and heating at the same time without effecting range to the extent of twice the figures I posted in above posts demonstrate.
Simon, I don't have a heat pump in my house for several reasons:
- My house isn't designed for the ducting required
- My house isn't inhabited throughout the day, so I don't require the heating running when I'm not there
I think, as usual, you've missed out a large part of what everyone else knows. Heat pumps are incredibly efficient but they have to be applied effectively. Retrofitting a heat pump to an existing central heating system is a stupid way to introduce lots of inefficiencies, why is why your poorly installed systems failed to meet their promises.
- My house isn't designed for the ducting required
- My house isn't inhabited throughout the day, so I don't require the heating running when I'm not there
I think, as usual, you've missed out a large part of what everyone else knows. Heat pumps are incredibly efficient but they have to be applied effectively. Retrofitting a heat pump to an existing central heating system is a stupid way to introduce lots of inefficiencies, why is why your poorly installed systems failed to meet their promises.
Max_Torque said:
SimonYorkshire said:
Why don't you try fitting a heat pumps evaporator to a heat pump at 100 Kelivn and seeing if any hot air blows out of the condensor.
With the correct choice of refrigerant, in a multi-stage system, then yes, "hot air will blow out of the condensor"Nasa use heat pumps to cool sensitive detectors in scientific / observational space craft, which sit at just a few mDegC above abs. zero......
But what do NASA know compared to you eh Simon........
Tell us about those batteries Nasa uses that in 10 years time will filter down so that they;re available for use in EVs? Oh right even Nasa haven't invented them yet.
R132 hardly a special choice of refrigerant. I stick LPG in anything that was designed for R12 lol.
Simon, this is hilarious because not only do I have an EV - my house also runs on a Daikin heat exchanger.
I can assure you they are a) not a scam b) used all over the world especially in Scandinavia and c) cheaper to run than gas heating.
Mine works right down to -15c. You don't seem to understand how they work at all.
Furthermore the Leaf (and other EVs) allow you to look at the energy use screen, in this screen it has a zone especially to show how efficient the heating is. As someone who had a gen1 leaf without this tech then a newer gen2 with this tech I can confirm it is substantially more efficient.
You are making such a fool of yourself on this thread that I just don't know what to say anymore. You might need help. I'm actually going from thinking it's funny to feeling sorry for you.
I can assure you they are a) not a scam b) used all over the world especially in Scandinavia and c) cheaper to run than gas heating.
Mine works right down to -15c. You don't seem to understand how they work at all.
Furthermore the Leaf (and other EVs) allow you to look at the energy use screen, in this screen it has a zone especially to show how efficient the heating is. As someone who had a gen1 leaf without this tech then a newer gen2 with this tech I can confirm it is substantially more efficient.
You are making such a fool of yourself on this thread that I just don't know what to say anymore. You might need help. I'm actually going from thinking it's funny to feeling sorry for you.
Evanivitch said:
Simon, I don't have a heat pump in my house for several reasons:
- My house isn't designed for the ducting required
- My house isn't inhabited throughout the day, so I don't require the heating running when I'm not there
I think, as usual, you've missed out a large part of what everyone else knows. Heat pumps are incredibly efficient but they have to be applied effectively. Retrofitting a heat pump to an existing central heating system is a stupid way to introduce lots of inefficiencies, why is why your poorly installed systems failed to meet their promises.
Yeah, next you'll probably say you spend most of the day out in your car on the road even though you only do 20 miles per day on average. - My house isn't designed for the ducting required
- My house isn't inhabited throughout the day, so I don't require the heating running when I'm not there
I think, as usual, you've missed out a large part of what everyone else knows. Heat pumps are incredibly efficient but they have to be applied effectively. Retrofitting a heat pump to an existing central heating system is a stupid way to introduce lots of inefficiencies, why is why your poorly installed systems failed to meet their promises.
But let's go with your flow. Other than connecting the heat pump to your houses central heating how would you heat your house via a heat pump and why would that way be more efficient than ocnnecting the heat pump to your existing central heating?
What systems do you reckon I have installed that failed to meet their promises?
jjwilde said:
Simon, this is hilarious because not only do I have an EV - my house also runs on a Daikin heat exchanger.
I can assure you they are a) not a scam b) used all over the world especially in Scandinavia and c) cheaper to run than gas heating.
Mine works right down to -15c. You don't seem to understand how they work at all.
Furthermore the Leaf (and other EVs) allow you to look at the energy use screen, in this screen it has a zone especially to show how efficient the heating is. As someone who had a gen1 leaf without this tech then a newer gen2 with this tech I can confirm it is substantially more efficient.
You are making such a fool of yourself on this thread that I just don't know what to say anymore. You might need help. I'm actually going from thinking it's funny to feeling sorry for you.
We'll look into this. Starting with how much power does your heat pump draw?I can assure you they are a) not a scam b) used all over the world especially in Scandinavia and c) cheaper to run than gas heating.
Mine works right down to -15c. You don't seem to understand how they work at all.
Furthermore the Leaf (and other EVs) allow you to look at the energy use screen, in this screen it has a zone especially to show how efficient the heating is. As someone who had a gen1 leaf without this tech then a newer gen2 with this tech I can confirm it is substantially more efficient.
You are making such a fool of yourself on this thread that I just don't know what to say anymore. You might need help. I'm actually going from thinking it's funny to feeling sorry for you.
You do realise that at the end of the day, if an EV has a heat pump that draws 1kw and it is 3x more efficient than a resistive heater the EV will still only have 3kw total cabin interior heating capability which would still be s
t even if it didn't lower the EVs range.....Oh, and you reckon you spend so much time out of the house, how would you know or care how warm it is?
SimonYorkshire said:
Yeah, next you'll probably say you spend most of the day out in your car on the road even though you only do 20 miles per day on average.
But let's go with your flow. Other than connecting the heat pump to your houses central heating how would you heat your house via a heat pump and why would that way be more efficient than ocnnecting the heat pump to your existing central heating?
What systems do you reckon I have installed that failed to meet their promises?
Oh dear Simon, you really haven't a clue.But let's go with your flow. Other than connecting the heat pump to your houses central heating how would you heat your house via a heat pump and why would that way be more efficient than ocnnecting the heat pump to your existing central heating?
What systems do you reckon I have installed that failed to meet their promises?
Evanivitch said:
SimonYorkshire said:
Yeah, next you'll probably say you spend most of the day out in your car on the road even though you only do 20 miles per day on average.
But let's go with your flow. Other than connecting the heat pump to your houses central heating how would you heat your house via a heat pump and why would that way be more efficient than ocnnecting the heat pump to your existing central heating?
What systems do you reckon I have installed that failed to meet their promises?
Oh dear Simon, you really haven't a clue.But let's go with your flow. Other than connecting the heat pump to your houses central heating how would you heat your house via a heat pump and why would that way be more efficient than ocnnecting the heat pump to your existing central heating?
What systems do you reckon I have installed that failed to meet their promises?
DELETED: Comment made by a member who's account has been deleted.
Next you;'ll be telling us you too have a heat pump at home lol. Funny how in recent posts I said anyone who owns an EV might just as well heat electric and run an ice instead of heating with gas and running an EV, yet nobody even mentioned that they heat electric. But now we have people coming out of the woodwork who do heat electric by means of a heat pump and run an EV.
Edited by SimonYorkshire on Monday 23 October 22:35
SimonYorkshire said:
Evanivitch said:
SimonYorkshire said:
Yeah, next you'll probably say you spend most of the day out in your car on the road even though you only do 20 miles per day on average.
But let's go with your flow. Other than connecting the heat pump to your houses central heating how would you heat your house via a heat pump and why would that way be more efficient than ocnnecting the heat pump to your existing central heating?
What systems do you reckon I have installed that failed to meet their promises?
Oh dear Simon, you really haven't a clue.But let's go with your flow. Other than connecting the heat pump to your houses central heating how would you heat your house via a heat pump and why would that way be more efficient than ocnnecting the heat pump to your existing central heating?
What systems do you reckon I have installed that failed to meet their promises?
SimonYorkshire said:
Next you;'ll be telling us you too have a heat pump at home lol.
Funny how in recent posts I said anyone who owns an EV might just as well heat electric and run an ice and nobody mentioned that they did heat electric and did run an ice, yet now we have people coming out of the woodwork who do heat electric by means of a heat pump.
DELETED: Comment made by a member who's account has been deleted.Funny how in recent posts I said anyone who owns an EV might just as well heat electric and run an ice and nobody mentioned that they did heat electric and did run an ice, yet now we have people coming out of the woodwork who do heat electric by means of a heat pump.
I realise that nobody has yet been able to paint a positive picture for EVs after I said this:
SimonYorkshire said:
I don't claim to be an expert in speed versus drag Rscott but I did find this on the web where Leaf owners are talking range between themselves
https://speakev.com/threads/leaf-speed-vs-range-gr...
In this you'll see some claim range might be as much as 120 miles in ideal conditions which include ideal temperature and battery condition (condition meaning age / previous use in the lifetime of the car so far). Ideal conditions seems to be effected by heating / ventilation / radio use, and there's talk of parasitic losses such as CPUs running in the background, and motor efficiency (motor torque versus motor rpm) which seems most efficient within a narrow band.
I also found this, which is info from Tesla about how speed and use (or not) of air con effects range. See half way down the page for the speed versus range graph. http://www.solarjourneyusa.com/EVdistanceAnalysis5...
According to the graph the Tesla's range is effected like this:
speed (mph) / range (miles) aircon off / range (miles) aircon on
20 / 410 / 237
40 / 312 / 250
50 / 267 / 225
55 / 237 / 210
60 / 215 / 190
65 / 200 / 180
120 / 85 / 80
Are these the sort of figures you're looking for Rscott? Best not forget these figures are for a Tesla that will seemingly do 400 miles on a charge. A Leaf won't do 400 miles on a charge will it? pmsl.
Tell you what I'll do for you though, bit more maths... So, best case scenario then let's assume Tinrobots Leaf is capable of 120 miles at 55mph (still, this will be with aircon etc off eh). The Tesla can do 237 miles at 55mph so let's assume the Leaf has 120/237ths of the range of the Tesla at 55mph and 120/237rhs of the range of the Tesla at 65 mph. 120/237ths of 200 is 101.3 miles. Seems about right to me, what do you think?.
Given the above types of figures, no wonder people on this thread have seen EVs doing 40mph on the motorway eh. I mean, it seems the Tesla will have nearly 50% more range at 40mph than at 60mph. The concepts are exactly the same between the Tesla / Leaf / any EV, so there's no reason not to expect a Leaf to have 50% more range at 40mph than at 60mph.
If you were in this car and on a journey to a destination (that hopefully has a charging point) 300 miles away, it isn't entirely obvious if it would make more sense to drive the 300 miles at 40mph taking 7 and a half hours without a stop or drive at 60mph which would take 5 hours in an ice but takes 5 hours plus a long charge in the Tesla, is it? You can scale all of that down to Leaf figures, because you won't find it very handy to drive 300 miles in a Leaf anyway eh.
Meanwhile, every ice can go with traffic flow and their drivers know that they will arrive at the destination quicker the faster they drive because refuelling doesn't take longer than a couple of minutes and they won't have to divert through any cities to find a fast charger (or any charger at all). Even an old V8 Rangerover will do 20mpg at 60mph, so even running on petrol the 300 miles would cost £90 in fuel or on LPG would cost about £45. You say average mileage for the entire week is less than half of this journey so the Rangerover driver would only usually spend £45 / £23 respectively on fuel per week which is less than the cost of having the EV sitting on the drive doing nothing. You could work out for yourself how the sums compare for a 40mpg average car and ask yourself whether someone who runs an average age average car is going to think it a great idea to switch to go out and buy a new EV.
TBH I don't really need heat pumps not to be 3x more efficient than resistive heaters to make my point on EV heaters do I? Look at the figures above again and gather your own thoughts as to how a mere 1kw worth of heating/AC effects EV range. It isn't an issue at all for ices is it!! Tomorrow I'll have my climate control on full heat with the AC on at the same time - how about you? You that run EVs won't (sorry) because that's not possible with your EV and even if it was it possible it would restrict your tiny range doubly as much as running just the heater or just the AC. I don't have to worry about 2kw, my lawn mower makes more power than that, my lawn mower can cut my grass all summer on a few litres of petrol. Electric lawnmowers are shttps://speakev.com/threads/leaf-speed-vs-range-gr...
In this you'll see some claim range might be as much as 120 miles in ideal conditions which include ideal temperature and battery condition (condition meaning age / previous use in the lifetime of the car so far). Ideal conditions seems to be effected by heating / ventilation / radio use, and there's talk of parasitic losses such as CPUs running in the background, and motor efficiency (motor torque versus motor rpm) which seems most efficient within a narrow band.
I also found this, which is info from Tesla about how speed and use (or not) of air con effects range. See half way down the page for the speed versus range graph. http://www.solarjourneyusa.com/EVdistanceAnalysis5...
According to the graph the Tesla's range is effected like this:
speed (mph) / range (miles) aircon off / range (miles) aircon on
20 / 410 / 237
40 / 312 / 250
50 / 267 / 225
55 / 237 / 210
60 / 215 / 190
65 / 200 / 180
120 / 85 / 80
Are these the sort of figures you're looking for Rscott? Best not forget these figures are for a Tesla that will seemingly do 400 miles on a charge. A Leaf won't do 400 miles on a charge will it? pmsl.
Tell you what I'll do for you though, bit more maths... So, best case scenario then let's assume Tinrobots Leaf is capable of 120 miles at 55mph (still, this will be with aircon etc off eh). The Tesla can do 237 miles at 55mph so let's assume the Leaf has 120/237ths of the range of the Tesla at 55mph and 120/237rhs of the range of the Tesla at 65 mph. 120/237ths of 200 is 101.3 miles. Seems about right to me, what do you think?.
Given the above types of figures, no wonder people on this thread have seen EVs doing 40mph on the motorway eh. I mean, it seems the Tesla will have nearly 50% more range at 40mph than at 60mph. The concepts are exactly the same between the Tesla / Leaf / any EV, so there's no reason not to expect a Leaf to have 50% more range at 40mph than at 60mph.
If you were in this car and on a journey to a destination (that hopefully has a charging point) 300 miles away, it isn't entirely obvious if it would make more sense to drive the 300 miles at 40mph taking 7 and a half hours without a stop or drive at 60mph which would take 5 hours in an ice but takes 5 hours plus a long charge in the Tesla, is it? You can scale all of that down to Leaf figures, because you won't find it very handy to drive 300 miles in a Leaf anyway eh.
Meanwhile, every ice can go with traffic flow and their drivers know that they will arrive at the destination quicker the faster they drive because refuelling doesn't take longer than a couple of minutes and they won't have to divert through any cities to find a fast charger (or any charger at all). Even an old V8 Rangerover will do 20mpg at 60mph, so even running on petrol the 300 miles would cost £90 in fuel or on LPG would cost about £45. You say average mileage for the entire week is less than half of this journey so the Rangerover driver would only usually spend £45 / £23 respectively on fuel per week which is less than the cost of having the EV sitting on the drive doing nothing. You could work out for yourself how the sums compare for a 40mpg average car and ask yourself whether someone who runs an average age average car is going to think it a great idea to switch to go out and buy a new EV.
t - which of you has one? Which of you prefers am electric lawn mower to a petrol mower? An EV is to ice cars what an electric lawnmower is to a petrol lawnmower, except you only ever need to cut your own grass and an electric lawnmower is always within reach of a plug socket at your house.Edited by SimonYorkshire on Monday 23 October 23:03
98elise said:
Let me know which reputable engineering or technology institution you would believe, and I'll dig out their take on the efficiency of heat pumps.
I have gathered my own first hand evidence of heat pumps.But I take your point and thank you for making it. I haven't even tried checkingh reputable engineering co's thoughts on heat pumps.
But I did quote reputable sources when talking about how range and use of heating or AC effects EV range and the figures are hardly compelling for EV;'s are they> Or perhaps on the one hand you would like us to believe first hand accounts from people who write positively about EVs on this thread while on the other hand you have us discount info from reputable sources on the same topic who all disagree with pro EV'ers on this thread.
Tinrobot...
Mpg was a typo, you know how the g is close to the h...
What other login do you think I have? You're wrong.
You stopped short of quoting the part of my post which discusses range versus speed. Everyone who has ever quoted any part of that (my) post also did the same. All those pro EV know that range versus speed is an issue for EVs, which is why you (they) did not quote me.
You'll obviously now feel repulsed by your 911's use of ice fuel from an ice pump and be selling to make space for another EV that runs on electric, electric that was made from, er, ice fuel?
But if you're not repulsed by your 911 you might think it a better idea to keep it, you know even if it is slower and handles worse than the Leaf at least if you go on a trip of a hundred miles or so you can be back in time for Cafe Nero at your place. Rather than having to charge the Leaf for a few hours at Starbucks.
Mpg was a typo, you know how the g is close to the h...
What other login do you think I have? You're wrong.
You stopped short of quoting the part of my post which discusses range versus speed. Everyone who has ever quoted any part of that (my) post also did the same. All those pro EV know that range versus speed is an issue for EVs, which is why you (they) did not quote me.
You'll obviously now feel repulsed by your 911's use of ice fuel from an ice pump and be selling to make space for another EV that runs on electric, electric that was made from, er, ice fuel?
But if you're not repulsed by your 911 you might think it a better idea to keep it, you know even if it is slower and handles worse than the Leaf at least if you go on a trip of a hundred miles or so you can be back in time for Cafe Nero at your place. Rather than having to charge the Leaf for a few hours at Starbucks.
SimonYorkshire said:
DELETED: Comment made by a member who's account has been deleted.
Next you;'ll be telling us you too have a heat pump at home lol. Funny how in recent posts I said anyone who owns an EV might just as well heat electric and run an ice instead of heating with gas and running an EV, yet nobody even mentioned that they heat electric. But now we have people coming out of the woodwork who do heat electric by means of a heat pump and run an EV.
Edited by SimonYorkshire on Monday 23 October 22:35
Don't have an EV though as no one produces a convertible or estate, so we can't replace either car yet.
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