Comment on Baby dies after California mom leaves him in car to get lip filler on 101-degree day, police say
FuglyDuck@lemmy.world 1 day agoAnd that assumes the AC didn’t crap out earlier because it was left idling in ridiculous heat. The system is not designed to be idled that long, and the cooling systems assume the car is moving for most of the time it’s on. (Both the engine and the cabin ac here.)
Even if the car didn’t turn off automatically, it’s still dangerous and in the “extremely stupid” degrees of negligence.
Pika@sh.itjust.works 1 day ago
Firmly agree with the statement that it was irresponsible because yes it was regardless.
However, disagree with the statement that a climate control system is not meant to be operated while idle. That is an old myth that I expect came from back when there was fewer electrical components in the car so not turning the ac /off/ before turning the vehicle off would risk damaging the cars electrical.
To a vehicle’s climate control system it doesn’t give a damn if it’s driving or idle. Now, while being idle, you have less fuel efficiency, And if you don’t have the engine running, it will drain more battery than needed, which will make your battery less efficient. But as for actual wear and tear on the components, running it at idle is almost no difference than whether you’re driving with it on.
Again, though, didn’t claim it wasn’t irresponsible either way, But it’s highly unlikely that Climate system would have failed if the vehicle had stayed on.
FuglyDuck@lemmy.world 1 day ago
that’s not actually a myth. The car is functionally not designed to be left on idle for extended periods. (Note, I’m saying extended periods. Warming/cooling your car at idle is normal. idling at a stop light is normal. Five minutes while waiting to pick some one up is normal. Leaving it to stay cool for 2 hours is outside that design window.)
When an engine is idling, it’s turning at a lower RPM than when moving. of particular note here is that the alternator and AC compressor are both driven by the serpetine belt directly connected to the crankshaft. The lower RPM makes both less efficient. For the compressor, what this means is that the AC system is turning more slowly than it normally would, reducing the total amount of cooling. For the alternator; it produces less electricity and may cause the battery to be discharging. Depends on some things, including how hard the AC is having to work, etc.
Further, because the car is not moving, there is less air moving around the engine compartment (or wherever the radiator for the engine and the AC is located.) This equates to higher operating temperatures for the engine, as well as yet more reduced ability for the AC system to remove excess heat from the cabin.
just because an AC can be run at idle for extended periods doesn’t mean it’s designed to, and doing so, especially on old or poorly maintained systems, in excessive heat, is likely to cause it to crap out where it wouldn’t have normally. Is it a particularly high probability? Not really. Is it still too high considering it’s a life-safety system? fucking absolutely.
brygphilomena@lemmy.dbzer0.com 1 day ago
This very much depends on the car.
Most modern computer controlled cars will not discharge the battery at idle unless you have a powerful sound system or an alternator that’s already on its way out. And they can adjust idle anyway if needed, most will increase idle when AC is turned on now to compensate the increased load on the engine. Driving the AC compressor is such a light load compared to the moving a 2 ton vehicle.
Also, many newer cars may even run an electric compressor instead of one driven off the motor. Think hybrid vehicles, it wouldn’t be feasible to have an AC system that turns off half the time if it’s running on the electric motors.
What you might deal with is heat soak if the fans can’t move enough air over the condenser core. But modern vehicles are immensely more efficient than even 10 year old vehicles.
FuglyDuck@lemmy.world 1 day ago
You’re point?
They’re not designed to idle for extended periods, and doing so puts strain on the systems. that the cars are “more efficient” doesn’t change that.
the AC compressor isn’t a significant load, no. But it’ expects a certain engine RPM coming into it, and it’s designed at that. It’s significantly less when the engine is idling because that’s below it’s designed range. There’s a reason the manufacturers tell you not to idle your car for extended periods (mine says more than 10 minutes, my last one said 5.) and this is part of it.
the increase in RPM modern cars do isn’t for the AC system. it’s to keep the engine from stalling and running smoothly… the compressor is still not designed to operate at that RPM.
LustyArgonianMana@lemmy.world 1 day ago
And she had a hybrid vehicle btw
LustyArgonianMana@lemmy.world 1 day ago
It’s a Toyota hybrid though, they are regularly used for camping.
www.reddit.com/r/priusdwellers/
The engine getting overheated isn’t usually a concern because it only turns on to charge the big battery. Sometimes if it’s hot inside the car, the engine in Toyota hybrids will stay on indefinitely, but thats to reduce the heat on the big battery. If the inside of the car is cool, then the big battery is cooled and the engine won’t stay on.
I would never use this info as an excuse to do what she did though ofc, no one should leave children that small unattended in a car, not even for 5minutes.
psx_crab@lemmy.zip 1 day ago
You doesn’t sounds confident on something you claim tbh. Also it’s a lot of technical truth but not really claim.
Car usually idle at 700/800rpm, this is normal working rpm for both alternator and compressor(because of course it is). Unless your car is about to stall due to whatever issue your car have, it should be within the normal working rpm and have enough refrigerant pumped. Variable compressor is even better, as it can adjust the amount of refrigerant pumped based on the car’s rpm, instead of only work well within a fixed range of rpm.
For alternator, there’s regulator inside that can control the voltage it output based on the rpm. The voltage output need to be stable across all normal working rpm, and if the voltage drop too much under load and in idle rpm, it’s most likely there’s underlying issue with your alternator. So if the voltage output is so low while idling that it discharge the battery, your alternator need to be replaced.
For the engine, moving air doesn’t cool the engine too much, it’s the coolant running within the car engine that’s cooling it. Moving air only ever cool the engine so slightly that it’s considered negligible, and i dare say, it won’t matter. If your engine run hot while idling for a long time, there’s likely an issue with your engine cooling system, be it clogged radiator, faulty waterpump, bad thermostats, etc etc.
Also AC condenser is usually locate in front of a radiator, right at the front grille, and its cooled with a fan sucking air in from the outside. A slightly hot engine compartment does not affect the cooling capability much as the air flow will not allow the hot air to reach the condenser. The fan also blow right at the engine, so the argument of less air flowing through the engine compartment does not make sense to me.
If your compressor spoiled earlier than it would because you idle a lot, it’s not because it’s being run in idle and idling cause it to fail early, it’s because while it’s idling you’re using it, as people usually judge a car usage by the mileage and never calculate how much they leave their car in idle, making it feels like it failed prematurely. It’s a total myth that doesn’t make any sense.
Also it’s a hybrid.
Source: am mechanic