2000 Watt Inverter Question

This is the place for any magazine-related discussions that don't fit in any of the column discussion boards below.
User avatar
Electronic Tek
Posts: 8
Joined: Mon Aug 25, 2008 11:30 am
Location: Houston, Texas
Contact:

2000 Watt Inverter Question

Post by Electronic Tek » Mon Aug 25, 2008 12:03 pm

I am trying to install an Air Conditioning window unit in my car. I plan on using another battery in line with the car’s battery in parallel and placing a 2000 watt Inverter in front of the Air Conditioning window unit. I was told in doing this I could cause damage to the PCM or other electronic components in the car. My other intention is to hook the battery with the inverter, but instead use a diode from the alternator to that battery keeping the battery separate from the original car battery. I intend on placing all of this in my trunk. I do have a center fold down in my rear seat to allow the Air Conditioning air to pass through. I also plan on placing the window unit in a galvanized pan with a 3 inch high wall with a drain connection. I plan on running the hose from the drain connection out the side fender where I have a vent port from the trunk. Any few back or ideas are greatly appreciated. Just to inform you. This is a 1999 Grand Prix with a 102 amp alternator. It will cost over $500 for me to do it myself, which includes a new condenser, dryer and replacing the evaporator. For a mechanic to do it not including labor it will cost over $1000.

User avatar
Externet
Posts: 1834
Joined: Fri Feb 01, 2002 1:01 am
Location: Mideast USA
Contact:

Post by Externet » Mon Aug 25, 2008 1:34 pm

That will be an olimpic medal...
- Abolish the deciBel ! -

User avatar
dacflyer
Posts: 4436
Joined: Fri Feb 08, 2002 1:01 am
Location: USA / North Carolina / Fayetteville
Contact:

Post by dacflyer » Mon Aug 25, 2008 7:33 pm

sounds like something for the blue collar comedy tour..lol

Hmm why couldn't you get the parts you need off of a junker truck ?
that inverter might produce too much heat if its inside the truck..

i had an old 69 ford F100 with a 300 straight-6 a real work horse of an engine. anyway the truck never had any A/C in it. i knew the basics of A/C and so i decided to goto a junk yard and build my own.
just by luck i found a under the dash after market unit, that needed a little TLC, but i still needed the compressor and the rest of the stuff..
i got the condenser unit (outside under the hood unit) off of an old compaq car, it had the electric fan attached to it. i go the receiver / dryer unit off of another car. and i found me a YORK compressor off of another ford car, this compressor was huge, almost like a single cylinder engine or a air compressor. and way. i got all i needed, went home, fabricated the motor mount for the compressor, couldn't find one that would mount onto the engine, so i made one. i went to a local auto parts and had the hoses made, i installed them, i also replaced the reciever/dryer can with a new one. you never can trust a used one. they soak up moisture fast, later had them pump & fill the system, no leaks :D when the unit was working it was so darn cold, that on a moist day the unit would blow out fogg.. even on low!
that was best unit i ever had..

well i wish you luck on your project, make sure you use very heavy cables going to the inverter..



.
.

User avatar
kheston
Posts: 348
Joined: Wed Dec 03, 2003 1:01 am
Location: CA
Contact:

Post by kheston » Mon Aug 25, 2008 8:04 pm

Even with your 102A alternator, your charging system isn't going to keep up with the A/C unit. You're a little over 500w short just to run the air conditioner.

You'd be much better off pulling the A/C components out of another Pontiac and installing them in your Grand Prix as Dacflyer suggests. This would leverage the engine's mechanical power directly and keep your alternator free from strain. If you have to buy everything outright, this may be a cheaper option than the system you propose.

If you're going for a full-on straw hat and overalls thing, consider mounting a swamp cooler in the roof. Be sure and post a video on YouTube and give us a link if you do.
Kurt - SF Bay

User avatar
MrAl
Posts: 3862
Joined: Fri Jan 11, 2002 1:01 am
Location: NewJersey
Contact:

Post by MrAl » Tue Aug 26, 2008 5:17 am

Hi,


Perhaps a small AC unit. Some of the smaller ones draw around 3.5
amps at 120vac and that's about 35 or more amps at 12v.
Even a small 'house' AC unit would cool the inside of a car pretty fast.
I'd get the smallest AC unit i could find.

There is a question i would have, and that is will the AC unit start up
with the given converter? The surge current when the AC is turned on
could be 20 amps or more for a short time. If this causes the converter
to shut off that wouldnt be good. A good test would be to run the
converter with the AC unit a few times, turning it on, then off, then wait
1 minute, turn on again, etc., to make sure it can turn on ok with the
chosen converter.
LEDs vs Bulbs, LEDs are winning.

dyarker
Posts: 1713
Joined: Fri Aug 22, 2003 1:01 am
Location: Izmir, Turkiye; from Rochester, NY
Contact:

Post by dyarker » Tue Aug 26, 2008 6:09 am

How big is the vent in the trunk? The heat that the AC removes from air going into passenger compartment will be dumped inside the trunk, plus heat from inverter, plus heat from compressor and fan. The trunk is going to get HOT unless there is A LOT of air flow.

Cheers,
Dale Y

User avatar
Janitor Tzap
Posts: 1433
Joined: Sat Aug 12, 2006 5:17 pm
Contact:

Post by Janitor Tzap » Tue Aug 26, 2008 7:21 am

Ha Ha!!! :lol:

You have got too be kidding right?

Why would you stick a 110AC Air Conditioning window unit into a car?
When the car probably already has Air Conditioning.

And even if it is to replace say, the broken Air Conditioning System under the hood.
The cost of the extra Batteries, Inverter, Higher Current Alternator.
Plus, any extra hardware needed to mount it into the car.
Would cost more than just repairing the Old Air Conditioning System.

If your truly going to do this.
Take a look at this page from Jc Whitney first.
These unit's are designed for RV's.
http://www.jcwhitney.com/autoparts/Sear ... ing+System


Signed: Janitor Tzap

User avatar
dacflyer
Posts: 4436
Joined: Fri Feb 08, 2002 1:01 am
Location: USA / North Carolina / Fayetteville
Contact:

Post by dacflyer » Tue Aug 26, 2008 1:06 pm

i have seen a few people here stick small unts in the back window of vans, but they are running them off of grid power when camping etc.

User avatar
dacflyer
Posts: 4436
Joined: Fri Feb 08, 2002 1:01 am
Location: USA / North Carolina / Fayetteville
Contact:

Post by dacflyer » Tue Aug 26, 2008 1:15 pm

lol.. these fotos might give ya some ideas...


Image


heres another.. rooftop mounted.


Image


forgive me, but i had to post these..heehee good luck.

.
.

User avatar
Janitor Tzap
Posts: 1433
Joined: Sat Aug 12, 2006 5:17 pm
Contact:

Post by Janitor Tzap » Tue Aug 26, 2008 5:34 pm

Dacflyer, those pictures are hilarious! :lol:
dacflyer wrote:i have seen a few people here stick small units in the back window of vans, but they are running them off of grid power when camping etc.
Yeah,
I've seen people putting Small Window Air Conditioners into Conversion Vans, Campers, or Converted Buses.
Running them off a 5000Watt Generator, plus running their Microwave, Satellite Dish, TV, Stereo, and Lamps. :)

But the idea of mounting a Window Air Conditioner on to a small car is just ridiculous too me. :lol:


Signed: Janitor Tzap

User avatar
jollyrgr
Posts: 1289
Joined: Thu Jan 03, 2002 1:01 am
Location: Northern Illinois
Contact:

Post by jollyrgr » Tue Aug 26, 2008 10:33 pm

There are numerous inverters working just fine in cars and trucks. As long as you get the wiring gage right, you should be okay. Do realize you will be drawing over 170 amps at full load which is more than your standard alternator can provide. Sorry to put engineering into this project.

And I'll confess, I've considered this as a real project but not so redneck. I shall explain my configuration in a moment. I know about the AC unit in the back window of vans and have seen at least one in operation while the car was driving. (There was condensate dripping out the back of the AC at a stop light.) I have ideas how this must have been done as I don't think an inverter was being used.

Putting a small 5000 BTU AC in a car should be enough I would figure for a small car. Possibly double that for a van or SUV. But here is how I would modify the redneck system. I would remove the existing condenser and evaporator coils from the car along with the receiver dryer (accumulator) etc. Next I would take the compressor and coils from the window AC and install them in the previous locations for the equivalent coils and put the compressor where the receiver dryer (accumulator) was at. POSSIBLY I would reuse the car tubing to extend and connect the coils to the compressor. You would need something flexible as standard copper tubing won't cut it. (Maybe use tubing found in gage sets for AC service???) It would be redneck but it would be under the hood and out of the line of cameras.

The window blower would not be used and the fan at the front of the car as well as the blower for the car's heating and cooling would be used as normal. This leaves only the window AC compressor to be powered by the car.

For a 10K BTU window unit the power is about 1000 Watts. (See this example: http://www.globalindustrial.com/gcs/pro ... ing-nextag) Now subtract the blower motor current (event though small) as it won't be used. Even at 1000 watts (with a 2000 watt inverter to compensate for the surge current) we are drawing at LEAST 84 amps steady state not counting inverter loss. I could probably see a 5000BTU unit working out as we are now down to 42 amps using the figures above. This is getting much better. A quick search of a 5000 BTU unit shows they draw 4.9A at 110V (530 Watts in the specs).

Here is how I would think I could get this to work properly. I would remove the automotive compressor and replace it with a 110V generator found in a "portable" generator. Since these portable gen sets use a 5 HP or less engine a car could EASILY power the generator. Problem is there is so little room to install the generator I doubt it can fit. Another solution would be to replace the original auto compressor with a second dedicated high power alternator. This would feed an inverter directly and drive the compressor. To control the window compressor, use a relay to turn the inverter on and off.
No trees were harmed in the creation of this message. But billions of electrons, photons, and electromagnetic waves were terribly inconvenienced!

User avatar
jwax
Posts: 2151
Joined: Mon Feb 09, 2004 1:01 am
Location: NY
Contact:

Post by jwax » Wed Aug 27, 2008 2:46 am

Is it April 1 already?

dyarker
Posts: 1713
Joined: Fri Aug 22, 2003 1:01 am
Location: Izmir, Turkiye; from Rochester, NY
Contact:

Post by dyarker » Wed Aug 27, 2008 6:59 am

Must be! Nobody else seemed to notice he intends to put entire window air conditioner in trunk with only condensation vented to outside. Except dacflyer and Janitor Tzap, they're talking about amps.
Dale Y

User avatar
Externet
Posts: 1834
Joined: Fri Feb 01, 2002 1:01 am
Location: Mideast USA
Contact:

Post by Externet » Wed Aug 27, 2008 11:08 am

... And those are not starting Amperes... :shock:
- Abolish the deciBel ! -

User avatar
jollyrgr
Posts: 1289
Joined: Thu Jan 03, 2002 1:01 am
Location: Northern Illinois
Contact:

Post by jollyrgr » Wed Aug 27, 2008 2:41 pm

dyarker wrote:Must be! Nobody else seemed to notice he intends to put entire window air conditioner in trunk with only condensation vented to outside. Except dacflyer and Janitor Tzap, they're talking about amps.
I know my first post in this thread was kind of long and could have been ignored. But I stated putting the coils from the window AC in the place the original car coils were at for my "design". Thus the window AC parts would be in the position that the original car coils were in. Condensate draining would work the same if this is done. I probably should of said something about putting the AC in the trunk won't work without external air flow. While not my "profession" I understand the refrigeration cycle and know that there are no real refrigerators; only heat movers.
Externet wrote:... And those are not starting Amperes...
Possibly I was too wordy and much of my intended information lost. But to quote my original post:
Even at 1000 watts (with a 2000 watt inverter to compensate for the surge current) we are drawing at LEAST 84 amps steady state not counting inverter loss.


I'm not being critical, just trying to point out that this was suggested.



I can understand the attractiveness of such a project. I needed to replace the condenser coil on my Suburban. Auto parts store price was anywhere from $130 to $180 for my coil. If I had a shop do the work it was going to be $800. I managed to find a coil on eBay for $90 (including shipping). For that same $90 I could have bought a full window AC at the local Wally World. Had there been an "easy" way to wedge a window AC in my car I would have considered it. I have given it thought, but I have not executed such a plan.
No trees were harmed in the creation of this message. But billions of electrons, photons, and electromagnetic waves were terribly inconvenienced!

Post Reply

Who is online

Users browsing this forum: No registered users and 10 guests