12 volt car heater/defroster that works?

Think not. A DC to Dc converter electronically creates an alternating current that then can be converted to a higher voltage through a transformer. Then it can be rectified back into a higher voltage DC.

Why would anyone want to do this? The process is inefficient.

It IS inefficient for a motor + resistance load esp. in a 12v system... but I don't understand your other point. You agree that a DC to DC inverter uses a transformer, then disagree that a DC to DC inverter uses a transformer. Let's rephrase the statement for those who didn't read/get the whole gist of the post back when it meant something: "Many DC to DC converters use a transformer, among other devices, to achieve their goal." To this I again say "I think so". I went off tangent a few posts back and wrote 'dc to dc' which in of itself would not make sense for a high voltage heater/fan. The original intent was to show the silly and bulky nature of what would be required to create heat electrically vs just replacing the heater core. Again, I should have typed 'inverter'. Next we can go over the alternate methods to step up DC voltage to either AC or DC without the use of a transformer. That'll serve the OP well, I'm sure.

Toyota MDT in MO

Please consider what the heater core gas to do in sub-zero temperatures and how infrequently heater cores fail before making statements like: "The engineers who designed it this way, denying easy access. Well, they should make them change one heater core, that would bring them back to the drawing boards." Where else would you put the heater core so it would provide heat at minus 5 degrees and not take up precious room inside the very small car that you own.

Actually, its not all that inefficient. But it depends on what the final goal is- if you are trying to operate devices that by design require higher than 12 volts (24 or 48 volt radio amplifiers, etc) then it makes sense. But just to run current through a resistor to make heat? No need in that case.

I agree. A component that lasts 30+ years (provided you change the antifreeze at least once in a blue moon) can be buried deep and hard to access. Yes, its annoying when it does fail, but the alternative is to make other more likely to fail components harder to get to, give up passenger/cargo space, make the vehicle heavier, and make the vehicle more expensive.

How easy or hard it is to replace a heater core has little to no bearing on any of the reasons you list for making it hard to get to. The biggest bear in replacing the heater core is getting the plenum out of the car. They could easily design that plenum with an access panel that would allow you to get to the heater core and evaporator. They could also design an access cover in the floor pan to allow you to get to the fuel pump without having to pull the tank.

They don't do so because those items aren't likely to fail under warranty. It isn't even likely that they will fail while the original owner has the car. It saves the manufacturer a few cents per car and those penny's add up when you make a gazillion cars.

Steve B.

I have an 87 Accord that has two circular access hatches trunk... one for the fuel pump, and the other for the fuel level sending unit.

I actually had to do the fuel pump once, it was child's play. Only took a few minutes.

Erik

That is one of the reasons that Honda is doing well, and the big 3 are not. To a lot of people, details matter.

Yes a DC to DC converter does use a transformer and rectifier, but it would be incorrect to say that DC to DC conversion involves rectifying and transforming without mentioning the most important and relevant part of the process. That part is to first make an AC signal.

That same Accord also has spare bulb holders molded into the inside plastic tail/brakelight access covers (but didn't come with spares installed). :(

I've driven it since new, and have done 100% of the maintenance other than an alignment or two... it still has it's original starter, alternator, and even shock struts! It left me 'stranded' only once, and that was when the fuel pump failed. However, even that happened within easy walking distance of home.

Best car I've ever owned... my only complaint is the paint has now lost it's 20 year battle with the Sun. Even so, it didn't start looking really skanky till 3 or 4 years ago.

Erik

In NYC, Con Ed generation plants sell their waste steam, which is still perty high pressure for waste steam, to various building for heat. They charge a fortune for it, as well.

It doesn't make sense to and I doubt that it is possible to make every part in the car easy to access. Why spend the money to provide great access for a part that rarely gets replaced. It would needlessly jack up the price of the car and complictate it's design.

The "core" in heater core refers to the fact that it's actually the core of your car. They start with the heater CORE and build the rest of the car around it.

Well, it sure seems that way. ;)

Ray

I and others replied to it.....

Mike

I disagree.

At the expense of a bigger plenum that eats into passenger space, makes the vehicle heavier, or makes it more expensive. Oh wait, I already said that... ;-)

Chrysler LH cars already have that feature, and have had since their inception in 1993.

Phooey- Chrysler LH cars have access panels over the fuel pump as well. AND most Chrysler engines aren't valve-smashers with timing belts like ALL Honduh engines are- now THAT is a dumb idea.

Priced a junkyard 2.7 recently?

Designing an engine to be 'non interference' in the event of a timing belt failure takes a big chunk out of it's efficiency potential. If you look, you'll notice most of today's engines are of the interference design.

Here's a list of most of the engines out there right now... the ones footnoted with an asterisk are interference engines.

Sorry about the long link, you may need to copy/past some to get it to work. The file it points to is a 2.7 MB pdf from the Gates website

Erik