8 ms·

This one is pretty cool and definitely surprised me. > Motor Humming or Whirring when Navigating to a Supercharger … > In some circumstances (such as cold we

This one is pretty cool and definitely surprised me. > Motor Humming or Whirring when Navigating to a Supercharger … > In some circumstances (such as cold weather), it is normal for the motor(s) and components to make noise, such as humming or whirring as it generates heat to warm the Battery. Super cool that the motors can be used for things other than moving the vehicle. It reminds me of how ESCs for RC vehicles use the motors to generate audible chirp tones to indicate status. Motors are multi-purpose devices!

Waterluvian 3y ago
I always thought about this growing up. How the engine’s heat is used directly to heat the cabin and there is no heater. Also my gaming PC in the winter. It feels like free compute given I’m heating anyways.
- bigyikes 3y ago
  > Also my gaming PC in the winter. It feels like free compute given I’m heating anyways. Totally. If it's cold and you have an idle rig, you might as well use it to run a crypto miner before reaching for an actual heater.
  - xur17 3y ago
    Assuming you use electric resistive heat. The math changes a bit for gas or heat pumps.
  - Rebelgecko 3y ago
    Actual heating systems can be better than 100% efficient, while crypto mining or cinebench or whatever is <100%
    - koverda 3y ago
      what do you mean?
      - kalleboo 3y ago
        Heat pumps which use energy to move heat around are more efficient than using energy to generate heat directly.
      - vGPU 3y ago
        Heat pumps can provide an “efficiency” of some 300-400%+. The “trick” is that they use electricity to move heat instead of creating heat, which is why heat pumps stop working well under a certain temperature. They kinda work like a reverse refrigerator. A fridge takes heat out from the inside and moves it to the outside. A heat pump does the opposite.
        stephen_g 3y ago
        You’ve completely failed to answer their actual question, it was the claim of less than 100% efficient heating they were asking about…
        vGPU 3y ago
        No. He was replying to this post: > Actual heating systems can be better than 100% efficient, while crypto mining or cinebench or whatever is <100%. The intricacies of why a crypto minor is less than 100% efficient when working as a heater are easily deduced, unless you’re precisely the sort of midwit that likes to leave replies such as the one you left.
    - josephcsible 3y ago
      How can anything be <100% if producing heat is the goal? Where would the rest of the energy be going?
      - wardedVibe 3y ago
        They mean a heat pump. You apply work to transfer heat, getting more inside than if you had just turned the energy into heat directly; the outside gets colder of course. https://en.wikipedia.org/wiki/Heat_pump#Principle_of_operation https://en.wikipedia.org/wiki/Heat_pump#Principle_of_operati...
        josephcsible 3y ago
        Yes, heat pumps are over 100%, but isn't turning the energy into heat directly exactly 100%?
        Adverblessly 3y ago
        As a random thought, for resistive heating some energy is definitely "lost" as light.
        krallja 3y ago
        Even light will eventually be absorbed by some surface and become heat.
      - stephen_g 3y ago
        I’m not sure what they mean about crypto miners or computers (mentioning cinebench), basically all the energy going in should be turned into heat so that should be near enough to 100% efficient. Where else would the energy be going? Sure, there will be a bit of RF power (Wi-Fi and some EMI) and depending on the device, a bit of light (LED indicators, monitor backlight) but that should be tiny compared to the energy that will end up as heat… In terms of heating systems though, it’s normal for fuel based systems to be <100% because you need to vent exhaust, and a lot of your heat your fuel produced can be rejected away from where you want it with that. For example, older gas boilers might only be 80% efficient or so, and even the much more efficient condensing boilers are still only in the low 90s.
  - jowea 3y ago
    Won't you damage your GPU faster by doing that?
- anikan_vader 3y ago
  It's free electricity, but a computing device still makes for a pricey space heater.
- jacquesm 3y ago
  A gasoline based ICE is so incredibly inefficient it needs to shed heat or it would melt down. It makes more heat than that it makes motive power (the thing it is designed to do...). A 50 KW engine makes 200 KW(!!) of heat (at full throttle). Most of that heat energy exits the system through the exhaust gases but there is plenty that gets stuck in the body of the engine and you need to remove it from there somehow before it causes damage. That's where your cooling system comes in, a coolant (typically: water or glycol or a mixture) passes through its own channels in the engine around the thermally loaded parts such as the cylinder and head walls to remove the heat. This coolant is pumped around in the engine using the coolant pump to a radiator, usually located at the front of the car in the airstream to help reject the heat to the environment. The interior heater of a car basically just re-routes a bit of that heat in the cooling system into the cabin through a miniature radiator with a fan connected to it that doesn't vent into the environment but into the cabin. So there is plenty of waste heat to go around. Some diesels got so efficient though that they needed an extra in-line heater to have enough heat for the cabin in specific operating domains (low power engine, low revs). It is effectively co-generation: you get two different kinds of energy (motive and heat) and you use them for different purposes.
  - dmix 3y ago
    I always wonder how you know so much about so many topics to make quality comments on a wide variety of topics on HN. Truly a jack of all trades. Maybe it's like how I spend so much time reading random Wikipedia articles on topics because I need to know how everything works.
    - jacquesm 3y ago
      Hm... too many projects :) And that list is only getting longer, I think I'll pass it on to my kids. Right now (and for the past couple of years) it has been mostly music but also still some more interesting tools to play with. Currently making a set of super realistic traffic lights for my youngest including pedestrian crossing and automatic cycle influencing (road coil pickup to detect car presence in front of the lights) for his model cars. Green wave, the works. I've mostly stopped writing up the projects, but still have a bunch of posts pickled that I probably should finish. Most recent software bit: ear training module for pianojacq.com is work in progress (press low 'A' on an 88 key keyboard to enable the secret menu that will enable the ear trainer, it is not quite ready for mass consumption yet but it is getting there).
- afavour 3y ago
  Unfortunately I have a vivid memory of the opposite: driving an extremely decrepit old car through the south in July, had to crank the heat to max to try to direct the heat away from the engine. No AC in the car, naturally.
  - JoBrad 3y ago
    I also have this memory. The A/C is a heat pump that just pulled heat to/from the radiator, which is used for both the engine and the A/C. So turning on the heat causes the thermostat to be tripped faster (or so I was told), moving heat away from the engine. You had to be moving for this to work well, especially if your thermostat was going bad.
dralley 3y ago
My understanding is that high-end residential heat pumps (e.g. Mitsubishi HyperHeat) will do this at lower temperatures as well. If the temp drops into the zone where the heat pump starts losing effectiveness (which on such systems is still pretty low, supposedly mine provides the full heat rating down to around 0F), they can run the blower motor in a less efficient regime to supplement the heat pump with a bit of resistance heating, without needing to fall back to a true "auxillary" heat source like heat strips or a furnace. That can extend the effective range down to a few degrees below zero (Fahrenheit). Since I live in the southeast, that's more than good enough to skip installing any auxillary heat source in the first place.
- dosshell 3y ago
  Interesting, that does not sound efficient? How much more efficient than using electrical heating directly instead? 0F ? That can't be right? My Mitsubishi gives heat to around -31F (MSZ-RW Sumo)
  - londons_explore 3y ago
    The efficiency of electrical resistance heating is exactly the same whether you use motor coil resistance or resistance wire. However, they simplify their system design a little (fewer contactors, fewer wires, fewer components to buy/test)
    - stavros 3y ago
      It's not the same if you generate the heat outside and bring it inside, though. I don't know enough about where the fan is located to know if that's what you mean, but that would be different.
      - raccoonDivider 3y ago
        Logically you'd keep as many parts as possible inside, where the temperature is easier to control?
spike021 3y ago
I have a relatively analogue car (Subaru BRZ) and there are times when you shut it off on a warm day and then randomly about ten mins later a radiator fan kicks on. I guess it's to help cool down but I don't remember exactly what the manual says. Basically it's cool how cars do things largely on their own sometimes to stay within certain parameters.
- rpmisms 3y ago
  My Kawasaki Ninja 500 will do the same thing, and it's a bike with very old tech. It is air-cooled, so it's probably a safety feature. Still cool.
  - akira2501 3y ago
    Supposedly one of the arguments for lane splitting in California was the propensity for bikes to overheat out here when stopped in traffic. My 650 did not have a fan but it did a good enough job heating up my crotch to a nearly unbearable degree on a hot day without it.
    - IgorPartola 3y ago
      I have certainly experienced overheating due to traffic on my air cooled bike. Now I am thinking about adding a fan to my oil cooler that would either be on a switch or even on a proper thermostat.
      - rpmisms 3y ago
        I have as well, and it's why I'm getting a liquid-cooled bike.
- throwawaaarrgh 3y ago
  The fan is triggered by a relay, triggered by the ECU, which uses coolant sensors (the thermostat sensor that is iirc not always the mechanical thermostat) to adjust when to cool the radiator. That temp is much higher than the ambient air will ever get, so if the fan comes on after the car is turned off then either it was just about at the temp that would have turned on the fan, or something could be slowly going wrong with the car to trigger the fan unnecessarily. A car is a system of systems so many different things can cause it. If it happens a lot (when turned off) I'd think about having an inspection done. Worst case scenario, engine ends up overheating, warps or explodes, and you need a new one. Coolant system is one of those "oh shit" systems that you need to pay close attention to.
pests 3y ago
This was def a noticable thing in the M3 before they added the dedicated heat pump.
jon-wood 3y ago
> It reminds me of how ESCs for RC vehicles use the motors to generate audible chirp tones to indicate status. Super Mario Wonder from Nintendo recently uses the vibration motors in your controller to play sound effects in some places which I thought was an incredibly neat trick.
rainbowzootsuit 3y ago
Back when I watched more F1 racing they had a musical performance where they used the telematic systems of some cars, with their high revving motors, to play notes ie the telematics selectively. I couldn't readily find a reference but remember the event.
- wrycoder 3y ago
  It's on YouTube. Star Wars, as I recollect.
- NextHendrix 3y ago
  https://www.youtube.com/watch?v=XRXwWbo_mX0 https://www.youtube.com/watch?v=XRXwWbo_mX0 Maybe this is what you're referring to. There are similar examples where people do this with old disk drives and printers too.
  - rainbowzootsuit 3y ago
    I'm pretty sure this is exactly it. Thank you!
- NextHendrix 3y ago
  https://www.youtube.com/watch?v=kCCXRerqaJI https://www.youtube.com/watch?v=kCCXRerqaJI The floppotron
queuebert 3y ago
The Car Care Nut talked in detail about the multi-purpose design of Tesla's heating systems: https://www.youtube.com/watch?v=7HC72p2gfuQ https://www.youtube.com/watch?v=7HC72p2gfuQ
bitwize 3y ago
> Super cool that the motors can be used for things other than moving the vehicle. It reminds me of how ESCs for RC vehicles use the motors to generate audible chirp tones to indicate status. > Motors are multi-purpose devices! In WALL-E, one of the robots following the title character, lacking any audio output, spins its motors at different rates to play the tune from Hello, Dolly! that it had learned from WALL-E. See also the Floppotron: https://www.youtube.com/watch?v=oGfkPCZYfFw https://www.youtube.com/watch?v=oGfkPCZYfFw
yonatan8070 3y ago
This reminded me of the SmartKnob View I saw on YT a while back, it's a knob built on a burshless motor that's controlled to provide the user with software defined feedback like tactile clicks and end stops https://youtube.com/watch?v=ip641WmY4pA https://youtube.com/watch?v=ip641WmY4pA

Waterluvian 3y ago

I always thought about this growing up. How the engine’s heat is used directly to heat the cabin and there is no heater. Also my gaming PC in the winter. It feels like free compute given I’m heating anyways.

bigyikes 3y ago
> Also my gaming PC in the winter. It feels like free compute given I’m heating anyways. Totally. If it's cold and you have an idle rig, you might as well use it to run a crypto miner before reaching for an actual heater.
- xur17 3y ago
  Assuming you use electric resistive heat. The math changes a bit for gas or heat pumps.
- Rebelgecko 3y ago
  Actual heating systems can be better than 100% efficient, while crypto mining or cinebench or whatever is <100%
  - koverda 3y ago
    what do you mean?
    - kalleboo 3y ago
      Heat pumps which use energy to move heat around are more efficient than using energy to generate heat directly.
    - vGPU 3y ago
      Heat pumps can provide an “efficiency” of some 300-400%+. The “trick” is that they use electricity to move heat instead of creating heat, which is why heat pumps stop working well under a certain temperature. They kinda work like a reverse refrigerator. A fridge takes heat out from the inside and moves it to the outside. A heat pump does the opposite.
      - stephen_g 3y ago
        You’ve completely failed to answer their actual question, it was the claim of less than 100% efficient heating they were asking about…
        vGPU 3y ago
        No. He was replying to this post: > Actual heating systems can be better than 100% efficient, while crypto mining or cinebench or whatever is <100%. The intricacies of why a crypto minor is less than 100% efficient when working as a heater are easily deduced, unless you’re precisely the sort of midwit that likes to leave replies such as the one you left.
  - josephcsible 3y ago
    How can anything be <100% if producing heat is the goal? Where would the rest of the energy be going?
    - wardedVibe 3y ago
      They mean a heat pump. You apply work to transfer heat, getting more inside than if you had just turned the energy into heat directly; the outside gets colder of course. https://en.wikipedia.org/wiki/Heat_pump#Principle_of_operation https://en.wikipedia.org/wiki/Heat_pump#Principle_of_operati...
      - josephcsible 3y ago
        Yes, heat pumps are over 100%, but isn't turning the energy into heat directly exactly 100%?
        Adverblessly 3y ago
        As a random thought, for resistive heating some energy is definitely "lost" as light.
        krallja 3y ago
        Even light will eventually be absorbed by some surface and become heat.
    - stephen_g 3y ago
      I’m not sure what they mean about crypto miners or computers (mentioning cinebench), basically all the energy going in should be turned into heat so that should be near enough to 100% efficient. Where else would the energy be going? Sure, there will be a bit of RF power (Wi-Fi and some EMI) and depending on the device, a bit of light (LED indicators, monitor backlight) but that should be tiny compared to the energy that will end up as heat… In terms of heating systems though, it’s normal for fuel based systems to be <100% because you need to vent exhaust, and a lot of your heat your fuel produced can be rejected away from where you want it with that. For example, older gas boilers might only be 80% efficient or so, and even the much more efficient condensing boilers are still only in the low 90s.
- jowea 3y ago
  Won't you damage your GPU faster by doing that?
anikan_vader 3y ago
It's free electricity, but a computing device still makes for a pricey space heater.
jacquesm 3y ago
A gasoline based ICE is so incredibly inefficient it needs to shed heat or it would melt down. It makes more heat than that it makes motive power (the thing it is designed to do...). A 50 KW engine makes 200 KW(!!) of heat (at full throttle). Most of that heat energy exits the system through the exhaust gases but there is plenty that gets stuck in the body of the engine and you need to remove it from there somehow before it causes damage. That's where your cooling system comes in, a coolant (typically: water or glycol or a mixture) passes through its own channels in the engine around the thermally loaded parts such as the cylinder and head walls to remove the heat. This coolant is pumped around in the engine using the coolant pump to a radiator, usually located at the front of the car in the airstream to help reject the heat to the environment. The interior heater of a car basically just re-routes a bit of that heat in the cooling system into the cabin through a miniature radiator with a fan connected to it that doesn't vent into the environment but into the cabin. So there is plenty of waste heat to go around. Some diesels got so efficient though that they needed an extra in-line heater to have enough heat for the cabin in specific operating domains (low power engine, low revs). It is effectively co-generation: you get two different kinds of energy (motive and heat) and you use them for different purposes.
- dmix 3y ago
  I always wonder how you know so much about so many topics to make quality comments on a wide variety of topics on HN. Truly a jack of all trades. Maybe it's like how I spend so much time reading random Wikipedia articles on topics because I need to know how everything works.
  - jacquesm 3y ago
    Hm... too many projects :) And that list is only getting longer, I think I'll pass it on to my kids. Right now (and for the past couple of years) it has been mostly music but also still some more interesting tools to play with. Currently making a set of super realistic traffic lights for my youngest including pedestrian crossing and automatic cycle influencing (road coil pickup to detect car presence in front of the lights) for his model cars. Green wave, the works. I've mostly stopped writing up the projects, but still have a bunch of posts pickled that I probably should finish. Most recent software bit: ear training module for pianojacq.com is work in progress (press low 'A' on an 88 key keyboard to enable the secret menu that will enable the ear trainer, it is not quite ready for mass consumption yet but it is getting there).
afavour 3y ago
Unfortunately I have a vivid memory of the opposite: driving an extremely decrepit old car through the south in July, had to crank the heat to max to try to direct the heat away from the engine. No AC in the car, naturally.
- JoBrad 3y ago
  I also have this memory. The A/C is a heat pump that just pulled heat to/from the radiator, which is used for both the engine and the A/C. So turning on the heat causes the thermostat to be tripped faster (or so I was told), moving heat away from the engine. You had to be moving for this to work well, especially if your thermostat was going bad.

dralley 3y ago

My understanding is that high-end residential heat pumps (e.g. Mitsubishi HyperHeat) will do this at lower temperatures as well. If the temp drops into the zone where the heat pump starts losing effectiveness (which on such systems is still pretty low, supposedly mine provides the full heat rating down to around 0F), they can run the blower motor in a less efficient regime to supplement the heat pump with a bit of resistance heating, without needing to fall back to a true "auxillary" heat source like heat strips or a furnace. That can extend the effective range down to a few degrees below zero (Fahrenheit). Since I live in the southeast, that's more than good enough to skip installing any auxillary heat source in the first place.

dosshell 3y ago
Interesting, that does not sound efficient? How much more efficient than using electrical heating directly instead? 0F ? That can't be right? My Mitsubishi gives heat to around -31F (MSZ-RW Sumo)
- londons_explore 3y ago
  The efficiency of electrical resistance heating is exactly the same whether you use motor coil resistance or resistance wire. However, they simplify their system design a little (fewer contactors, fewer wires, fewer components to buy/test)
  - stavros 3y ago
    It's not the same if you generate the heat outside and bring it inside, though. I don't know enough about where the fan is located to know if that's what you mean, but that would be different.
    - raccoonDivider 3y ago
      Logically you'd keep as many parts as possible inside, where the temperature is easier to control?

spike021 3y ago

I have a relatively analogue car (Subaru BRZ) and there are times when you shut it off on a warm day and then randomly about ten mins later a radiator fan kicks on. I guess it's to help cool down but I don't remember exactly what the manual says. Basically it's cool how cars do things largely on their own sometimes to stay within certain parameters.

rpmisms 3y ago
My Kawasaki Ninja 500 will do the same thing, and it's a bike with very old tech. It is air-cooled, so it's probably a safety feature. Still cool.
- akira2501 3y ago
  Supposedly one of the arguments for lane splitting in California was the propensity for bikes to overheat out here when stopped in traffic. My 650 did not have a fan but it did a good enough job heating up my crotch to a nearly unbearable degree on a hot day without it.
  - IgorPartola 3y ago
    I have certainly experienced overheating due to traffic on my air cooled bike. Now I am thinking about adding a fan to my oil cooler that would either be on a switch or even on a proper thermostat.
    - rpmisms 3y ago
      I have as well, and it's why I'm getting a liquid-cooled bike.
throwawaaarrgh 3y ago
The fan is triggered by a relay, triggered by the ECU, which uses coolant sensors (the thermostat sensor that is iirc not always the mechanical thermostat) to adjust when to cool the radiator. That temp is much higher than the ambient air will ever get, so if the fan comes on after the car is turned off then either it was just about at the temp that would have turned on the fan, or something could be slowly going wrong with the car to trigger the fan unnecessarily. A car is a system of systems so many different things can cause it. If it happens a lot (when turned off) I'd think about having an inspection done. Worst case scenario, engine ends up overheating, warps or explodes, and you need a new one. Coolant system is one of those "oh shit" systems that you need to pay close attention to.

pests 3y ago

This was def a noticable thing in the M3 before they added the dedicated heat pump.

jon-wood 3y ago

> It reminds me of how ESCs for RC vehicles use the motors to generate audible chirp tones to indicate status. Super Mario Wonder from Nintendo recently uses the vibration motors in your controller to play sound effects in some places which I thought was an incredibly neat trick.

rainbowzootsuit 3y ago

Back when I watched more F1 racing they had a musical performance where they used the telematic systems of some cars, with their high revving motors, to play notes ie the telematics selectively. I couldn't readily find a reference but remember the event.

wrycoder 3y ago
It's on YouTube. Star Wars, as I recollect.
NextHendrix 3y ago
https://www.youtube.com/watch?v=XRXwWbo_mX0 https://www.youtube.com/watch?v=XRXwWbo_mX0 Maybe this is what you're referring to. There are similar examples where people do this with old disk drives and printers too.
- rainbowzootsuit 3y ago
  I'm pretty sure this is exactly it. Thank you!
NextHendrix 3y ago
https://www.youtube.com/watch?v=kCCXRerqaJI https://www.youtube.com/watch?v=kCCXRerqaJI The floppotron

queuebert 3y ago

The Car Care Nut talked in detail about the multi-purpose design of Tesla's heating systems: https://www.youtube.com/watch?v=7HC72p2gfuQ https://www.youtube.com/watch?v=7HC72p2gfuQ

bitwize 3y ago

> Super cool that the motors can be used for things other than moving the vehicle. It reminds me of how ESCs for RC vehicles use the motors to generate audible chirp tones to indicate status. > Motors are multi-purpose devices! In WALL-E, one of the robots following the title character, lacking any audio output, spins its motors at different rates to play the tune from Hello, Dolly! that it had learned from WALL-E. See also the Floppotron: https://www.youtube.com/watch?v=oGfkPCZYfFw https://www.youtube.com/watch?v=oGfkPCZYfFw

yonatan8070 3y ago

This reminded me of the SmartKnob View I saw on YT a while back, it's a knob built on a burshless motor that's controlled to provide the user with software defined feedback like tactile clicks and end stops https://youtube.com/watch?v=ip641WmY4pA https://youtube.com/watch?v=ip641WmY4pA