Remove and Replace Air Conditioning ? 7

[RWF7437]

Is it possible to remove the air conditioning components from a 1999 Toyota RAV4 and replace them later if necessary to use the vehicle for a trade in ? How practical and or expensive might this be ? Would better gas mileage be achieved by doing this

 

[patprimmer]

Yes, yes, not very, quite and slightly.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[IRstuff]

Such an operation might involve venting the refrigerant into the atmosphere by an unlicensed technician, which would be against the law, in the US.

TTFN

FAQ731-376

 

[TheBlacksmith]

1) If you're not using the AC, the clutch doesn't engage.
2) The weight of the removed components aren't very much, probably about 50-75 pounds or half a passenger.
3) Depending on your climate, the AC may be necessary to defog your windsheild on humid days.
4) If you must, can you just remove the belt? Many vehicles have two serpentine belt sizes, one goes around the AC, the other jsut the rest of the accessories.

Seems like a lot of work for minimal gains - see comment #1.

 

[Comcokid]

If you remove the AC components, it's best to completely flush the system as you remove it. The PAG oil used with R134A will absorb moisture and break down. You will have to discard the dryer as the dessicant will pick up moisture. Plug the open ends of all hoses and components.

I can't see that you will gain anything by doing this. The losses of a belt on an unused A/C compressor are probably unmeasureable in terms of MPG. If MPG is the issue, you would do far better keeping your tires properly inflated, checking your tire alignment, using a lower viscosity oil, replacing your air filter regurarly, or even leaving your spare tire home.

 

[NormPeterson]

At least part of the gains you'd make in reduced engine load are offset by increased aerodynamic drag.


Norm

 

[RWF7437]

aerodynamic drag ? On What ?

 

[MacGyverS2000]

At least part of the gains you'd make in reduced engine load are offset by increased aerodynamic drag.

Say wha?

Dan - Owner

http://www.Hi-TecDesigns.com

 

[BrianPetersen]

What they're saying is that if you roll the windows down at highway speed in an attempt to not be cooked inside, it considerably increases aerodynamic drag on the vehicle. There could be more total power drain on the vehicle this way, than if the windows were rolled up and the air conditioning was on ... and the latter situation is a lot more comfortable.

 

[reidh]

Back to the OP, is the main goal of removing the AC to save fuel?

-Reidh

 

[BrianPetersen]

If that is the objective, it will never be enough to pay for the labour cost and the refrigerant recovery and refill operations. Power demand on the A/C system is pretty much nil if you simply switch it off.

 

[MikeHalloran]

In the US, it would be illegal for a licensed technician or other paid professional to vent refrigerant into the atmosphere.

Not so for a DIYer. It's not a good idea because it's a waste of expensive refrigerant, but it's not illegal.




Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

I think this is the consensus

1) It is a fair bit of work to remove everything, especially the parts that are integrated into the ventilation / heating / demisting system.

2) It is more work and cost to later replace it as some parts will be damaged by storage and exposure to moisture in air.

3) Fuel savings by not running the compressor in hot weather will be offset to some degree increased aero drag by driving with windows down. This will be very car model and speed dependant.

4) Fuel savings all year round due to decreased weight will be real, but insignificant.

5) Safety will be significantly decreased due to significant loss in drivers viability due to loss of demisting function. This alone probably makes it illegal in some areas.

6) Not mentioned so far is reduced handling qualities due to change in weight without correcting ride height, spring rate and alignment changes.



Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[RWF7437]

Thanks to all for your replies. Although automobiles were made for over 100 years without A/C it seems modern cars, and people, cannot live without such things. I live in the Pacific Northwest where A/C is only useful for 10 to 20 days a year. I like hot weather and feel comfortable at 85° F. I drive slower than 50 mph probably 90% of the time when "drag" is hardly likely to be a major problem.

This is what prompted my question in the first place. And yes, I did Google it for hours without getting any helpful answers.

Thanks again to all.

 

[FoMoCoMoFo]

The problem is in that requirement that it be replaceable. Find a vehicle you wont ever want to trade in then get rid of the A/c !

 

[patprimmer]

I think you still maybe need the demist function. A/C has an extreme effect on demist speeds.

Before A/C was virtually standard, cars had a lot more internal volume for their seating capacity, with much more vertical glass and flipper vents. Also, we expected to warm them up before moving off. Also we accepted poor vission at times as normal. Standards regards expected safety have changed.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[rmw]

It has been an interesting discussion of the pros and cons of A/C. Having lived through the days of no A/C through the days of add-on A/C's to modern systems, I don't want to go back. RWFetc, if you don't want the A/C, most systems I have seen have a switch somewhere that says "on/off" in some form or fashion. So if you aren't hauling freight of some kind where the weight savings is critical, just turn the thing off and do without it except on those 20 days (boy you guys have long summers out there) when you need it. It seems like the best of both worlds to me.

All facetiousness aside, it has been a good discussion. Thanks for posting the thread.

rmw

 

[IRstuff]

Sure, you can simply pull the breaker on the magnetic clutch.

This will disable the A/C and the only load will be the bearing for the clutch plate, which ought to be insignificant, compared to a bunch of other factors.

This would seem to be the simplest solution, although, you probably should run the A/C every so often to keep the lubricants and whatnot in running order.

TTFN

FAQ731-376

 

[Comcokid]

In some places A/C is not an option - it's a necessity. I lived in Florida for 10 years. In the summer, temperature and relative humidity are typically the same - 95/95 - or higher. Going somewhere was more of an exercise in moving from air-lock to air-lock.

I had two cars during this time. First one didn't have functioning A/C. I kept a refrigerator full of Gatorade, and got about 50 miles to the quart.

Second car I installed a modified Fluiddyne racing radiator so both the car and the A/C would remain cool when in stopped traffic (modified as a standard racing radiator doesn't have brackets to support the A/C fan, nor the cooling circuit for an automatic). Too many newer cars size the radiator size right at the margin. But when you've been driving 70 MPH, and suddenly have to come to a full stop in bumper-to-bumper traffic in the hot Florida sun over hot blacktop behind a buss that is dumping 150 degree air directly into your radiator, A/C cooling begins to approach a life-and-death situation. You're sure not going to turn on the heater to help cool the car engine, and you can't survive without the A/C for long.

 

[dcasto]

And all you who like to "blow out the cobwebs" the AC cuts out at high RPMs too, giving all your torque to the wheels and not the AC.