Does turning on your heat when the engine is cold make the heater warm up faster?

[0roo0roo]

might be faster to have it on from the start. from what i know the normal radiator isn't used until the engine reaches a certain temp. and cars computer will hold gears longer o speed up warmup...so maybe it'll compensate. atleast with autos

 

[Pacfanweb]

Originally posted by: Kenazo

Originally posted by: Pacfanweb
Absolutely it will slow the heating process. The heater core is just a mini radiator that the blower pushes air across.

I hear this being written by many people in this thread and it's absolutely false. Although you are cooling the coolant by having the heater fan going before the engine is warm, that heat is going somewhere, and it is going into the cab of the vehicle.

Will it be a noticable amount? no, probably not, but if you're going to get technical, it is heating the cab up, however little.

This is of course assuming that it's the same temperature inside the car as outside. If the cab of the vehicle is already warmer than the environment (b/c of the greenhouse effect of the windows, or it was in a garage or something), then you'd be better off leaving the heater off.

Sorry, but this is not false. Running the heat with the engine cold will slow the engine from warming up. Maybe it won't be by a noticeable amount in some cars, but if we're getting technical, then yes is absolutely does slow the warm-up process.

And the little heat that's going into the heater core at first will still be cold air when it gets to you. So it might be 35 instead of 32 degrees....doesn't matter. Your body will still think it's cold, and you will be waiting that much longer to actually feel warm air.

 

[villageidiot111]

Turning the heat up does not make it heat up faster, and probably makes the heating up process a little slower.

 

[IamElectro]

Originally posted by: Rastus
Some vehicles, when you turn the defroster on instead of the heater, while the car is still cold, will automatically turn the AC compressor on. They can get heat off an AC system faster than they can an engine. Then when the engine starts putting out heat, the AC turns off.

AC kicks on with defroster to dry the air so your windshield does not fog.

 

[benwah]

I'm fully aware of how car heaters work and as of late have begun to turn my heater on right away, on its lowest. I didn't always turn the heater on right away, but recently been a few times on my short commute to work, i've forgotten to turn it on, by the time i remember i'm already reaching my destination and don't have any ride left to enjoy the heat. As for the engine itself taking longer to warm with the heater on, i say bahumbug.

 

[DietDrThunder]

I'm fully aware of how car heaters work and as of late have begun to turn my heater on right away, on its lowest. I didn't always turn the heater on right away, but recently been a few times on my short commute to work, i've forgotten to turn it on, by the time i remember i'm already reaching my destination and don't have any ride left to enjoy the heat. As for the engine itself taking longer to warm with the heater on, i say bahumbug.

Maybe you should remember to turn your seat heater on.

 

[Captante]

It has no effect.

Untrue it will take the engine longer to get fully warm if you start dumping heat off of it from the moment you turn the key. It will also take longer to produce heat in the cabin but the difference will be smaller.

In fact you can actually lower the temp of a cars motor which is on the verge of overheating by cranking the heat to maximum and blasting the blower. (and often buy a few more miles of driving before engine damage to say limp off the highway)

I'm fully aware of how car heaters work and as of late have begun to turn my heater on right away, on its lowest. I didn't always turn the heater on right away, but recently been a few times on my short commute to work, i've forgotten to turn it on, by the time i remember i'm already reaching my destination and don't have any ride left to enjoy the heat. As for the engine itself taking longer to warm with the heater on, i say bahumbug.

wwybywb?

 

[Red Squirrel]

No, but I always turn up the heat to max that way when I use the auto starter it will eventually be warm enough. Downside is that uses a lot of gas so I refrain from always using auto start unless it's VERY cold. Wish cars would have an electric heater that would run until the engine is warm enough that way you'd get instant heat. The heat in your car is just waste heat from the engine so the engine has to actually warm up for it to work. When driving I'll turn it to the lowest setting just to have a bit of air hitting the windshield but no point in blasting it until the engine warmed up. I find a good indicator is when the engine temperature gauge starts to move it means it's starting to get warm enough for the heat to work. When it's pegged at the lowest indication the engine is not warm enough yet.

 

[boomerang]

Wish cars would have an electric heater that would run until the engine is warm enough that way you'd get instant heat.

https://en.wikipedia.org/wiki/Block_heater

An option on many cars and a necessity in some climates.

 

[NetWareHead]

My car has electric coil heater which delivers heat and windshield defrost air from a cold start. As the engine warms up, the car switches off this electric heater and draws warmth from the engine once it reaches operating temps

 

[Red Squirrel]

https://en.wikipedia.org/wiki/Block_heater

An option on many cars and a necessity in some climates.

That does not really do much for the car heat. It just makes it less hard on the motor for stating. Still takes a long time for the engine to reach a hot enough temp so that the heater works.

What would be nice though is if plugging in the block heater would also activate a plug inside the car, as you could plug in a regular space heater and warm up the cabin ahead of time with a timer. But I guess lot of people would set their cars on fire by using questionable wun hung lo brand heaters.

 

[tynopik]

My car has electric coil heater which delivers heat and windshield defrost air from a cold start. As the engine warms up, the car switches off this electric heater and draws warmth from the engine once it reaches operating temps

also electric cars use resistive heat (obviously)

of course who cares now that you can use your phone to preheat your car before you get there amirite?

 

[Red Squirrel]

of course who cares now that you can use your phone to preheat your car before you get there amirite?

Think only the Samsungs have this feature.

 

[NetWareHead]

That does not really do much for the car heat. It just makes it less hard on the motor for stating. Still takes a long time for the engine to reach a hot enough temp so that the heater works.

What would be nice though is if plugging in the block heater would also activate a plug inside the car, as you could plug in a regular space heater and warm up the cabin ahead of time with a timer. But I guess lot of people would set their cars on fire by using questionable wun hung lo brand heaters.

It actually does help get warm cabin heat much much sooner than starting an unheated cold engine. The sooner an engine reaches operating temp, or at least the threshold where the heater core can adequately supply the cabin hvac system with heat, the sooner you warm up the interior.

 

[rh71]

My '08 BMW (2 years after this thread was created) doesn't even allow the heat to go on until the car is actually running warm (sometimes up to 10 minutes). You can set it on intensive and it still won't blow anything until much later. In contrast, we have the heat (fan) on my wife's Hyundai up because of remote-start purposes and it's definitely warm in the car before the 10 minute mark. Even when we don't use the remote-start and just start driving and in about 5 minutes it's warm air. So in summary, BMW is being a Nazi in controlling the heat that I deserve earlier.

 

[Stopsignhank]

I will admit it is nice to pull up my car app on my phone and have it pre heat the car before I get into it. Nothing like getting into a car that is 72 degrees before you start it. I can have a it pre heat the car every day at the same time, but I don't always leave at the exact time so I just do it manually on my phone. Sometimes life can be so hard.

 

[Red Squirrel]

It actually does help get warm cabin heat much much sooner than starting an unheated cold engine. The sooner an engine reaches operating temp, or at least the threshold where the heater core can adequately supply the cabin hvac system with heat, the sooner you warm up the interior.

The margin would be very small though. We are talking about less than 1800w of heat going into the engine. It's enough to stop the oil and coolant from turning into a gel, but not really more than that. Though tbh I never bothered plugging in my car when it's warmer than like -30 so maybe when it's warmer out like -10 it actually would make a small difference?

 

[JulesMaximus]

I turn my heat on 12 years in the past thus ensuring that my car is nice and toasty by the time I want to drive it.

 

[NetWareHead]

The margin would be very small though. We are talking about less than 1800w of heat going into the engine. It's enough to stop the oil and coolant from turning into a gel, but not really more than that. Though tbh I never bothered plugging in my car when it's warmer than like -30 so maybe when it's warmer out like -10 it actually would make a small difference?

It is a small amount of energy I agree. The engine block heater I'm looking at for my car needs to energized for 4 hours at least in order to achieve any meaningful effect albeit a small one, overnight for best results. Engines and their associated components represent several hundred pounds of mass and offer considerable thermal inertia so its not going to warm up soon with a block heater. However, given enough time, even a small candle flame could eventually boil water.

Some anecdotal data from other customers who have installed it is drawn from the cold snap we experienced here in NH this winter where we had sustained sub-zero temps for more than a month: No block heater and the car took 15 minutes to warm up. Under similar morning temperatures using the block heater, the car reached operating temp in 5 minutes.

Actually, what Im considering is not really a block heater. It is really a coolant heater with recirculating pump that eventually warms the entire engine; metal, coolant and oil. I have a diesel daily driver and the increased amount of wear my engine sees when operating cold on slow to warm up days is enough to have me considering a recirc coolant heater. Plus the engine is way touchy when so cold, it stalls easier (manual trans) and is noticeably sluggish until it gets hot.