Most Durable HU

[DBfan187 5,000+ posts]

make the mounting location part of your AC duct. lol

 

[EdMuse 10+ year member]

AFAIK, in a DC circuit. Electrons flow from Negitive to Positive.

A quick search turned up:

http://www.glenbrook.k12.il.us/gbssci/phys/Class/circuits/u9l1a.html

Somewhere in this site, right next to an illustration of electron flow from a battery through a bulb back to the battery, from + to -, is the quote

"...Similar reasoning would lead one to conclude that the movement of positive charge through the wires from the positive terminal to the negative terminal would occur naturally."

That said, my explanation of positive gound circuitry might actually be utter bull. I'm an amateur physics buff, but I'm a musician and educator by trade, and electronics is not my strongest suit. Within the past five minutes or so, I've come to the concept that a positive gound system might involve the positive terminal of the battery being the high potential terminal, and so the electron flow would be attracted to it. Now I'll admit to not being as sure as I was a few minutes ago, but I can confirm it as true that negative ground is the way most, if not all cars have been made for about the last forty years, and my understanding is that if you put negative ground components into positive ground cars, or vice versa, without being very careful about how they are hooked up, they will fry, and quickly. Since my stereo is still working after two years, it can't be the issue.

-EdM.

 

[DBfan187 5,000+ posts]

not saying you're wrong, but what I was taught throughout all of my electronics classes, that in a DC circuit - electrons flow from negitive to positive.

 

[EdMuse 10+ year member]

...Most anything electronic has slits or vents of some kind so that heat can get away from the circuits.
...You will probably increase the temp of the head unit if you wrap it in insulation.

...Could you get some kind of thin insulation to wrap your ducting in and then maybe rig a fan or 2 behind the head unit to pull heat from off the unit? Just some ideas.

Yeah, you're probably right. I was thinking, though, that I can either try isolate the ductwork from the stereo, or the stereo from the ductowrk. If I do the latter, I'd be creating a little environment for the stereo that is independent of the rest of the environment behind the dash. I wasn't suggesting wrapping the entire stereo in insulation, just the bottom and sides, so the heat could rise up and out of the vent above it. Upon further consideration, though, I probably couldn't do this well enough for it to be effective. That elusive idea of a thin, flexible, but effective insulation is the problem. I' m not sure what to use, and I haven't found anything yet.

Any suggestions on what to use as a fan? It would have to be 12 volts, but about the size of a computer case fan.

BTW: I'm leaning, having read other threads at this site and spoken to some folks at Crutchfield, towards a Kenwood head. Unfortunately, they are rated for up to 140 degrees, so I'd still have to do something about the problem. And the person I spoke to there said "150 degrees? Is that celcius? No? What is that in celsius? 65? Well, uh, that SHOULD be okay, I guess." Didn't exactly inspire confidence. Still need more, better info from these companies.

-EdM.

 

[EdMuse 10+ year member]

make the mounting location part of your AC duct. lol

You mean to have the AC cool the unit? Actually, I'd think about it if the **** AC worked at all . I've thought about taking it out completely, as the compressor's bearings are going, the evaporator is in the way of some of the bolts I need to get to for the mods I'm doing on the front end tratment, and the comdensor is doing nothing but restricting airflow through the radiator. Pretty low priority, though, trying to pull out all those hoses, and reroute the belts. Whose friggin' idea was it to have the crank pully drive the AC condensor, then have a belt from the AC condensor drive the power steering pump? I love my car, but it's a shop monster.

Hey, it does make me think, though: are there systems out there for liquid cooling of components? You can do it with a computer, why not with a car stereo?

-EdM.

 

[wilzyx 5,000+ posts]

Beacuse it's not quite that simple. If it were, I would have done it originally. The problem is that there isn't enough space between the ducts and the bottom of the headunit's sleeve to get any decent insulation in there. There is, perhaps, 1/8" of clearance. Now, if you could suggest to me a material I could use that will provide enough insulation in that small amount of space, I would rip the dash out of my car to get it in.
Recommendations?

-EdM.

lots of foil

 

[UPCguy 10+ year member]

There is a good website, http://www.newegg.com, if you look on there, they sell all types of computer stuff. The water cooling thing, you might need a water block. If you are interested though, they might have that kind of stuff.

 

[fatryan 5,000+ posts]

yeah, the foil idea i gave you probably wont do the trick in itself, but i bet itll help at least a little. anything can absorbe 150 degrees or heat. but as we learned in grade school, darker objects atract and store heat much better than lighter objects. and reflective objects literally reflect light so they tend to absorbe even less heat. im not sure about the temperature characteristics of tin as opposed to aluminum, but i think theyre both pretty good at reflecting heat. if you dont wanna try that, and you cant come up with something else, just relocate the head unit

 

[EdMuse 10+ year member]

Okay, I think I've decided what I'm going to do. I just spoke with Blaupunkt, who told me that they don't publish ambient tem data on their gear (translation: the guy on the other end of the phone didn't know and didn't feel like checking), but that all stereos from any company would have the same resistance to heat. Now, this may well be bull, but where I've gotten about the same data from three different companies (140 degrees as the upper limit), I'm ready to believe it, if only so I can get on to replacing my HU.

I picked up some self-adhesive foil and foam duct insullation, about 1/8" thick. Originally, I was going to use it to wrap my ductwork, but the more I got to thinking about it, the more it occurred to me just how much ductwork I have, and how embedded it is behind the dash (the dirty little secret of Volvo 240 ownership, for instance, is that replacing the HVAC blower motor is an 8-hour job which requires the removal of most of the interior of the car). So, I think what I'll do is use this stuff to fashion a little space for the HU itself. The HU mounts top center in the dash, and just behind and above it is a vent. I should be able to insert the insulation below the sleeve, then attach the insulation to the underside of the dash, extending back to the vent. That way, the air in this little "micro-environment," heated buy the stereo, can escape through the vent, but the whole area will be insulated from the rest of the space behind the dash.

The crowning touch is born of the fact, related to me by my uncle who builds computers, that a PC's power supply puts out 12 volts. So, and 80mm computer case fan, mounted to the vent, and perhaps a slot dremelled into the trim above the HU as an intake, will keep a steady stream of airflow at the ambient temp of the cabin flowing over the top of the HU, carrying away the heat generated by the HU itself.

It may not be the best of all possible worlds, but it's probably the best I can hope for.

-EdM.