On a cold day when one starts their car they have to wait at least 10 minutes or more for the coolant from the engine to get warm enough so the heater starts putting out really warm air.
But if one just presses the button on the hand dryer in a restroom, nice warm air immediately billows out.
So why don’t auto companies use a combo of electric heat with the heater core so warm air comes out immediately? Once the coolant temp exceeds the capacity of the electric heat, the electric heat could automatically be disabled. What kind of heater are they putting in electric cars?
WAG - Coolant heat is a byproduct of running the engine. Adding an electric heater for personal comfort would put additional stress on the vehicle’s electric system especially during startup. It might even decrease the overall battery’s life.
I find if I have to let my car warmup, it’s because I’m outside clearing off the snow and ice from the vehicle. By the time I’m finished (especially with ice on the windows) my car is toasty warm inside, … about 10 minutes.
My girlfriend’s car has electric heaters in the seats than can be turned on right away after the engine starts. They’re much more effective at heating people than the air heater is, so it’s a more effective solution for the period of time when the engine hasn’t made a huge surplus of heat.
Are you just letting it idle or actually driving it?
The last three cars I’ve had I (a 96? Grand Am, a 03? Cavalier and a Honda Insight) might take that long to get heat to the cabin if they’re just sitting in the driveway running, but if I’m driving, I get heat in about [checks a map because I know exactly when it turns on] 1.5 miles or 4 minutes. In my other cars, I could do it quicker by driving in a lower gear.
My dads Tahoe will force the transmission to switch gears at higher RPMs when it’s colder out for the same reason.
I’ve thought about the idea of adding electric heat, but I think the added expense and additional problems that would occur with it would far outweigh the benefits it would add.
Would adding a block/oil pan heater get heat to the cab sooner? My gut says no. I’m thinking that those few extra degrees in the oil pan probably wouldn’t make much of a difference, but I really don’t know.
They do make interior, electric, window defroster/cab heaters that you can by at places like Wal-Mart, but when I tried one it didn’t make enough of a difference to be worth while, so I returned it.
it wouldn’t be that effective, especially not for the cost. hand dryers (and hair dryers) work because the working distance is very close, so the amount of energy needed for the heater coils isn’t too high. In a cold car, an electric heater would have to be a lot more powerful because a good portion of the heat it generated would go into warming up the HVAC manifold. by the time the air got to the vents, it would be barely warm.
The heating system in our car comes on pretty fast – but it’s a hybrid, and thus has a more robust electrical system than a pure internal-combustion car.
A 720 watt 12 volt heater would draw about 60 amps. This is more than all your electrical systems requirements if everything was turned on at the same time. Might be ok for 5 min or so but would require a slightly larger alternator in some cases.
When I’ve though about this, I always pictured the coils being very near the vents, not down by the core.
I’m not sure that has anything to do with anything. The hybrid battery, I believe, is only driving the motor, not the rest of the electrical system. In my hybrid, the ‘normal’ battery is actually pretty undersized. It’s about the size of a motorcycle battery. I couldn’t even jump someone’s car with it.
Also, the heat in your cab comes from the heat that the IC system creates, I don’t think the hybrid part contributes much to that other then some friction from the motor spinning.
I had an old car that used an electric heater and fan as the rear window defroster. It would take a healthy amount of juice to heat your whole car that way, although small fans that focus the heat directly on a passenger’s face would work. You can buy simple electric defroster fans that plug into the cigarette lighter, intended for windshields, but no reason you couldn’t turn them around and point them at the passengers.
on the contrary, the Toyota and Ford style hybrid systems use liquid cooling for the power electronics (and I think the traction motor as well.) though in those vehicles I think the cooling circuit for the electronics is separate from the one for the engine.
Block heaters do make an engine-warmup difference, from only about a quarter of the time after the engine starts to half the time, depending on the air temperature, from say, –10°C to –25 or –30. This was true with every car I owned.
But my current car’s block-heater extension cord has a small moulded plastic gizmo on it next to the plug that won’t allow the power to cut in until the outside temperature hits –18°C, so if the air is warmer than that but still cold, the car takes a much longer time before the engine is warm enough to pump out heat, even when it’s –25 or –30 and plugged in. The starter turns the engine over more slowly at –17 than it does when it’s –30 and the block heater was working.
The car’s extended warranty runs out in another 6,000 kilometres, at which point I’ll cut the plug and gizmo off and put on a new plug. I won’t do that now, not only because it’s too damn cold to fiddle with plugs, but because if the block heater dies, I can imagine the dealership refusing to fix it, claiming I shorted it out.
Why on Earth would it be set up that way? The coils on hand/hair dryers are right near the vents.
Also, remember, the OP is only talking about electric heat as a temporary fix until the regular heater core came up to temp., not as a full time heater.
In a world where they give you a cigarette lighter outlet but don’t put the actual cigarette lighter in it just so they can shave a few bucks here or there, I don’t really seeing most manufacturers installing a separate heater, with separate controls, just so you can heat your car up a few minutes earlier during the coldest part of the year.
Much simpler just to install a remote car starter so you can leave your car in the driveway with the heater running, then hit the remote five minutes before you head out the door and it’s like Palm Springs in your car. Well, maybe San Francisco, or Portland, but you get the idea.
Or buy an electric car warmer and leave it plugged in all night or for three or four hours before using the car. No more scraping frost off the windows.
But they’re a royal pain to the 10th power to install if you want it done properly. Otherwise, prop it up somehow, making sure all the vents aren’t blocked, and close the door on the wire.
The problems with this idea are almost too numerous to count.
Heater plenums are plastic. You need a heat proof material.
You will have to upsize the electrical system. 720 watts was mentioned upthread. Not nearly enough. You would probably need closer to 2500-3000 watts (my hair drier is 1800). For ease of math lets say 2800 W. That will require 200Amps. That is some serious power.
Put the coils near the vents? Riiiiight. And when the first brain dead moron stuff a piece of paper in the vent and the car burns down? Can you say lawsuit?
The idea is a non starter.
If your car takes 10 minutes of driving to warm up it seems like there is a problem. Lots cheaper to fix it.
My car (a VW) doesn’t warm up at idle. I can let it run for twenty minutes, and it is still blowing cold air when I get in. However, once I start moving, it then heats up very quickly.
From a cold start (in cold weather, obviously), it takes about ten miles to start blowing warm air. In part, this is because the first ten miles of my commute is a gentle downhill, so the engine doesn’t have to work very hard. Coming the other direction, the first ten miles of my commute is flat, and it warms up in about four miles.
Why would there have to be separate controls and such? It would all be automatic with the car using electric heat until the heater core received fluid that exceeded what the electric heat could churn out. Then it would automatically swap out the sources by having the electrical coil shut off and venting out heat from the core. Not rocket science really, and very doable.
All my cars that have/had automatics had remote starters. Love them!!!
But while it can be done they’re not the best idea for a stick shift. Plus, there are times when one needs to go NOW and instant heat would be nice.
I’ve had a few cars like that too. All transverse-mounted 4s. The engine sheds heat at or near the rate it makes it, when at idle on a cold day. I had an Escort that could be fully warm, but if allowed to idle for a long time (like 30 minutes) on a very cold day would actually cool off to where the heat was just warm-ish.
