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Heat pumps

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13

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  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    Burnt the face off me but I wanted to test it out of curiosity!

    :D


  • Registered Users Posts: 2,645 ✭✭✭krissovo


    What type of car is it if you don't mind the question?
    I did a 23 degrees mild weather test this morning with PTC and it was 10% of total energy used.

    Its a I3


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    How can you calculate heater usage in an i3 ?


  • Registered Users Posts: 862 ✭✭✭Busman Paddy Lasty


    krissovo wrote: »
    Its a I3

    Nice. Good i3 forums out there talking about HP energy savings dating back to 2014. Anecdotally 30% ish probably over 50% by now. HP as standard for i3's sold in Sweden apparently. No idea how they measured this or what they have to back up these claims.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    Nice. Good i3 forums out there talking about HP energy savings dating back to 2014. Anecdotally 30% ish probably over 50% by now. HP as standard for i3's sold in Sweden apparently. No idea how they measured this or what they have to back up these claims.

    A lot of guess work to be honest, unless they have dedicated tools to measure the current directly taken from the heating system from a car with and without HP, otherwise it's meaningless.


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  • Registered Users Posts: 862 ✭✭✭Busman Paddy Lasty


    A lot of guess work to be honest, unless they have dedicated tools to measure the current directly taken from the heating system from a car with and without HP, otherwise it's meaningless.

    Meaningless then :-(


  • Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 7,883 Mod ✭✭✭✭liamog


    Meaningless then :-(

    So far we have in agreement with the Korean Ministry of the Environment, Volkswagen, Tesla, and a BMW owners club. But yes, all meaningless :rolleyes:


  • Registered Users Posts: 862 ✭✭✭Busman Paddy Lasty


    liamog wrote: »
    So far we have in agreement with the Korean Ministry of the Environment, Volkswagen, Tesla, and a BMW owners club. But yes, all meaningless :rolleyes:

    Whoa, was only referring to the guesswork of a few posters on an i3 forum in 2014! How their estimations had no backup on that forum.


  • Registered Users Posts: 3,224 ✭✭✭Kramer


    There's an algorithm guys...........

    If:
    a. The initial cost of the heat pump
    b. The extra range benefit derived, by having a heat pump
    c. The financial savings accrued, by having a heat pump
    d. The environmental benefits, of significantly more efficient heating

    If b+c+d a, get a heat pump equipped car.
    Elon used this very same algorithm when deciding to add a heat pump in the Model Y.

    :D.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    Whoa, was only referring to the guesswork of a few posters on an i3 forum in 2014! How their estimations had no backup on that forum.

    Is that a fact ?


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  • Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 7,883 Mod ✭✭✭✭liamog


    Kramer wrote: »
    If:
    a. The initial cost of the heat pump
    b. The extra range benefit derived, by having a heat pump
    c. The financial savings accrued, by having a heat pump
    d. The environmental benefits, of significantly more efficient heating

    I only care about a and b, for me it's the consistency factor, each person will have different preferences, I'm glad the Mini SE comes with a heat pump as standard.


  • Registered Users Posts: 11,099 ✭✭✭✭the_amazing_raisin


    I feel there's one example that's been ignored so far, the Gen1 Nissan Leaf. Before 2013 it was fitted with a resistive heater, afterwards they added a heat pump. It seemed to make the difference for winter range for some people.

    My view is that it's a lot more up to personal habits than whether the heat pump is installed or not.

    If you pre-heat the cabin then that takes a lot of the initial heating load off the battery.
    If you set the heating to 19C it'll save more battery than 23C
    Longer journeys probably see less impact from heating than short ones, since once the cabin is up to temperature the load on the heater is low

    Personally, if all other things were equal I'd go for the heat pump simply because there's an efficiency gain with the heat pump. I think the Irish climate is suited for hat pumps since it doesn't get too cold here and if you can set the cabin temp a bit lower so the resistive heater doesn't kick in then you'll save more energy.

    I was disappointed to learn the VW ID models don't include a Heat pump in Ireland and I'd be looking to add one after purchase, assuming I get one

    "The internet never fails to misremember" - Sebastian Ruiz, aka Frost



  • Registered Users Posts: 12,111 ✭✭✭✭KCross


    liamog wrote: »
    I only care about a and b, for me it's the consistency factor, each person will have different preferences, I'm glad the Mini SE comes with a heat pump as standard.

    +1

    Financial savings are relatively speaking miniscule as are the environmental aspects. Its about price, convenience, range and whether it affects you at all.


  • Registered Users Posts: 12,111 ✭✭✭✭KCross


    I was disappointed to learn the VW ID models don't include a Heat pump in Ireland and I'd be looking to add one after purchase, assuming I get one

    How are you going to do that?

    This is an expensive, complicated piece of equipment that has to be tied into lots of car systems.


  • Registered Users Posts: 11,099 ✭✭✭✭the_amazing_raisin


    KCross wrote: »
    How are you going to do that?

    This is an expensive, complicated piece of equipment that has to be tied into lots of car systems.


    How expensive and how complicated? My understanding is that the MEB is based on modular toolkits, the heat pump would just be another kit. What would make it complicated would be if other parts need to be removed or moved around


    I said I'd look into it, it all depends on expense and complexity. We won't know either of those until VW release the ID3 parts list and service manuals

    "The internet never fails to misremember" - Sebastian Ruiz, aka Frost



  • Registered Users Posts: 12,111 ✭✭✭✭KCross


    How expensive and how complicated? My understanding is that the MEB is based on modular toolkits, the heat pump would just be another kit. What would make it complicated would be if other parts need to be removed or moved around


    I said I'd look into it, it all depends on expense and complexity. We won't know either of those until VW release the ID3 parts list and service manuals

    You can bet your bottom dollar that if you are buying/installing the OEM parts from VW and getting it added after purchase by VW that it will cost more than having it factory fitted.

    Getting your local indy to do it is highly unlikely in the medium term and is also unlikely to be financially viable. Your money would be better spent getting the longer range variant than any potential range issues in winter from not having the HP.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    Whoa, was only referring to the guesswork of a few posters on an i3 forum in 2014! How their estimations had no backup on that forum.
    Is that a fact ?

    Sorry, mis read what you said there hadn't got my coffee.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    I think 30 percent is a gross overestimate because if People are preheating off the battery then this is going to use the resistive heating and not the heat pump.


  • Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 7,883 Mod ✭✭✭✭liamog


    I think 30 percent is a gross overestimate because if People are preheating off the battery then this is going to use the resistive heating and not the heat pump.

    It's backed up by numerous sources at this point. I'm not sure there is a big heat pump conspiracy designed to hoodwink motorists out of the money. Why would preheating only use the resistive and not the heat pump?


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    liamog wrote: »
    It's backed up by numerous sources at this point. I'm not sure there is a big heat pump conspiracy designed to hoodwink motorists out of the money. Why would preheating only use the resistive and not the heat pump?


    Well unless things have changed with newer electric cars the HP only works when the High Voltage system is energised, so if preheating a lot off the mains the HP isn't going to be 30% more efficient than the resistive heating.

    I'm not saying the HP isn't more efficient but they are more important for lower range electrics. If it's free I'll take it but I wouldn't pay 1K more for one in a 300+ Km range EV considering the amount of times I need that kind of range.


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  • Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 7,883 Mod ✭✭✭✭liamog


    Well unless things have changed with newer electric cars the HP only works when the High Voltage system is energised

    Is your info based on the original Leaf implementation? I've not found any details either way re whether the heat pump is used on other cars during pre-heating. The Hyundai/Kia and Tesla systems, will be less efficient during pre heating, because they also scavenge heat from the other vehicle systems.

    I saw Munro's teardown of the octovalve in the Model Y, that's an impressive piece of engineering.


  • Registered Users Posts: 12,111 ✭✭✭✭KCross


    Who knows what VW have implemented but an important part of air based heat pumps is to have a large air flow over the coils to capture the heat. Thats easy to do when you are moving in the car. To make it happen on a car that is stationery outside your house would require you to spin up a fan. Think of the fan noise that you hear from some cars when they are DC charging!

    I'd imagine alot of people would not want to have that spinning up outside their door/neighbourhood every morning. Air based heat pumps are not quiet.

    In contrast a PTC heater just needs to pull juice from your charge point and run a small fan to circulate heat around the cabin.... very quiet and the designers dont have to worry about efficiency as the power is not coming from the HV battery... hence PTC over HP for pre-conditioning.

    Lets see what VW bring to the table. They might have a different design philosophy or maybe this new heat pump is so good it doesnt need much air flow.... we just dont know yet.... not long now though!


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    liamog wrote: »
    Is your info based on the original Leaf implementation? I've not found any details either way re whether the heat pump is used on other cars during pre-heating. The Hyundai/Kia and Tesla systems, will be less efficient during pre heating, because they also scavenge heat from the other vehicle systems.

    I saw Munro's teardown of the octovalve in the Model Y, that's an impressive piece of engineering.

    It's easy to know if the HP comes on during pre heat, if the radiator fan comes on then it's likely it does if not then it doesn't. You'll also hear the compressor.


  • Registered Users Posts: 1,558 ✭✭✭Ionised


    It's easy to know if the HP comes on during pre heat, if the radiator fan comes on then it's likely it does if not then it doesn't. You'll also hear the compressor.


    I have no idea what it is, but my Mini does make a fair noise when preheating. Sounds more pump than fan though.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    Ionised wrote: »
    I have no idea what it is, but my Mini does make a fair noise when preheating. Sounds more pump than fan though.

    All you have to do is listen for the radiator fan at the front bumper and it should be obvious if it's on.


  • Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 7,883 Mod ✭✭✭✭liamog


    If as KCross says the heat pump requires airflow, why wouldn't you engineer it to use the radiator fan to provide that airflow, the ducts will need to be there anyway for operation while driving.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    liamog wrote: »
    If as KCross says the heat pump requires airflow, why wouldn't you engineer it to use the radiator fan to provide that airflow, the ducts will need to be there anyway for operation while driving.

    They do, or at least the Leaf I did for when the car was stationary or driving slow. But not for pre-heating, no fan I assume no HP because it needs quite a lot of air.


  • Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 7,883 Mod ✭✭✭✭liamog


    Ok, so the rad fan being on, means the Mini SE could be using it's HP to pre-heat. I can't remember what the Ioniq does, as we don't tend to pre-heat it due to the plugged in requirement and no app :(


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    liamog wrote: »
    Ok, so the rad fan being on, means the Mini SE could be using it's HP to pre-heat. I can't remember what the Ioniq does, as we don't tend to pre-heat it due to the plugged in requirement and no app :(

    If the radiator fan is on when the car is pre-heating with the car turned off then there is a good chance the hp is running because I see no other reason it should be running, if the fan is off then there's no hp being used for pre-heat.


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  • Registered Users Posts: 1,558 ✭✭✭Ionised


    I'd better have a proper listen next time I'm preheating. This heat pump business seems awfully controversial reading through this thread.


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