Questions about Air Conditioning, ... help me make my car cooler! Options

[tygaboy]

@jd74914 - Thanks for the great input! I've been looking at this Orion fan and they do publish the fan curves, as seen here.
Any idea if a couple of these would work?
If you need me, I'll be off learning about static pressure!

[jd74914]

Thanks for the great input! I've been looking at this Orion fan and they do publish the fan curves, as seen here.
Any idea if a couple of these would work?
If you need me, I'll be off learning about static pressure!

Maybe. Not sure what the actual flow you need is. No idea what kind is on yours-though if you have a part number or some identifiers I'd be happy to take a look and offer some advice.

I just pulled out a spec sheet for a typical automotive-spec centrifugal blower. See how the static pressure vs. flow curve is significantly higher at low flows and has a different shape? That shape is rather important; as is the location your system falls on the curve.

For example, if the system used this blower and runs with 160 cfm air flow (this number is rather important since airflow really is what controls efficiency of the evaporator), the corresponding pressure drop of the system would be known to be 0.6 inWC (water column). To do the same thing with the axial fan you posted would require 5 fans. Or you could run at lower flows with less fans. Its tough to design without information since everything is very coupled. Likely Vintage Air uses those centrifugal blowers because the pressure curve has a lot of margin (until it hits the knee point) so they're less sensitive to long piping, lots of bends, etc. in terms of overall performance because the blower speed can always be turned down or they can have an overall governing pressure drop.

[jd74914]

Hopefully something there made sense or is useful. Unfortunately, a lot of engineering or trial and error goes into fan-based heat exchanger systems. I've worked on industrial systems on and off for the past dozen years, and automotive systems make me uncomfortable because there isn't much data in the public domain for cars. You really just have to guess sometimes, especially when it comes down to modifying aftermarket parts.

[914_teener]

Hopefully something there made sense or is useful. Unfortunately, a lot of engineering or trial and error goes into fan-based heat exchanger systems. I've worked on industrial systems on and off for the past dozen years, and automotive systems make me uncomfortable because there isn't much data in the public domain for cars. You really just have to guess sometimes, especially when it comes down to modifying aftermarket parts.

(IMG:style_emoticons/default/agree.gif)


Not only that but you have to make assumptions on radiant heat gain. In a 914 during the summer with no insulation behind you the heat gain assumptions become large.


Honestly, you are better off with an ice chest in the seat next to you and one of those directional fans blowing across the top of the ice at your body.

I admire your enthusiasm, and you most likely will learn a lot.

[white1975]

small made for classic mini japan

[Andyrew]

The case should have some kind of drain port you can use to orient it. Apart from that it shouldn't matter how you mount it. The best spot I found is either directly where the wipers are (no go for wipers) or where I'm mounting mine (glove box area cut into the firewall).

You can go all project Binky on us and totally make a custom housing to fit somewhere but it's all about those fans as they are the bulky item.

Thanks Andrew. I've started looking at DC brushless fans to replace the squirrel cage set up. There are some ~ 5" x 5" X 1.5" that appear to have adequate CFM.
Something like this would really open up where I could fit it and might allow me to totally hide it.
I'm pretty sure I can make this work and not have to cut into the front fire wall.

"Film at 11:00" as I futz with all this.

Thanks again!

I tried some computer fans like that. Didnt blow nearly any air. A remote mount centrifugal fan might be the best. I have a bilge fan I considered using but after some more trial I ended up just cutting everything out and mounting the whole universal unit. Or at least I wanted to make sure I had room for that when designing the dash.

[Andyrew]

small made for classic mini japan

Whats that from? (IMG:style_emoticons/default/idea.gif)

[tygaboy]

OK, so it seems the safest thing is to use squirrel cage fans. I think I'll fab up a case and orient everything to get the package more "914 shaped" while keeping the fan shafts horizontal.

Oh boy, more fab work! (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/smash.gif) (IMG:style_emoticons/default/welder.gif)

[Marv's3.6six]

I added a one off fresh air fan and are very happy with the results

To the right of my steering wheel is a ford f150 3" dash vent, behind that vent is a small bilge fan pulling air from under the dash board.... Believe it or not with that air directed straight at my face my car is bearable in most cases during the summer. The whole setup was cheap and only added about 3 lbs of weight to the car. The ashtray was removed for this add on.

[Steve]

Hi World - I need some info:
I'm working to add A/C to my build and I found this little set up that's 10.5" wide, 8.5" deep and 4.5" tall.

What I don't know is what's possible in terms of orientation of these evaporator/ fan units.

I know they have to drain any condensation (and not into the motor, etc.) but assuming I address that:

- Is there any appreciable impact to how the evap unit performs if it were stood on end, turned upside down, etc.?

Essentially, does refrigerant care about flowing up vs down vs sideways?

- Do any of the other components, like the expansion valve, care about orientation?

If needed, I'm totally OK with cutting up the case, making one that suites my needs and reusing the components.

Or, if there are other considerations, if I'm missing something, please let me know.

Thanks in advance for any help!
Chris

I bought the same evaporator and was going to do the same thing. The company I bought it from said to mount it at angle so the drain would work. You could easily make a center console to mount it in. I have a six and bought a Benling 12v compressor, so everything but the evaporator will be in the front trunk. Life keeps getting in the way, so this will be a winter project

[Rand]

AC is for weenies. Spritzer bottle.
(I know, I know)

Actually Rand, AC is for comfort Those who walk upright usually approve. (IMG:style_emoticons/default/av-943.gif)

I only teased. But I've used spritzer spray bottles to keep the extra AC junk off my minimalist cars and loved every minute of those experiences. I get the creature comfort mode. But I also really love jumping in the old beast with zero and finding other ways around it. It's part of the experience. 914s should not have all that. I have a Honda if I need to be practical. (IMG:style_emoticons/default/tongue.gif)