Whats up with AC, is this still 1940.

[Durango Dave]

The first car to come with factory AC was in 1940. So its been 77 years since that event and since we learned to turn hot air to cool air on the fly. Why is AC on anything anymore still a headache to this day.

Every time i turn around i read something automobile related either car, truck, or RV concerning AC. This AC uses too much or this generator cant power this AC, or the AC this or the AC that.. Whats up with the AC now days folks, why havent we mastered this science yet so that its not a problem anymore with power consumption or anything else for that matter.

Are we still back in 1940?


This came about because of the generator talk i have heard lately, and also because i have a APC (backup battery) for my computer so that i have time to shut it down in the event of power failure, it also protects my line from spikes and stuff like that.

Now every time the AC comes on my APC beeps letting me know there was a power surge or power loss or something up with the line in my RV.

Its annoying as heck to hear that every time the AC comes on.

Why hasnt mankind invented an AC that runs on lower electrical energy or even propane?

This way all these problems im hearing about running the AC will go away and mankind and RVers will be better off for it.

Is turning hot air to cold air such a complicated science that we cant do it cheaply or efficiently now days?

[THenman]

Air conditioners use a compression and expansion cycle exchange heat and to cool. Simple physics puts a lower limit of the energy required.
Now scroll compressors tend to be more efficient than piston compressors including variable displacement ones. Scroll however requires pretty small range of rpms to work well so they are not typically found in autos. (Some autos went that way and had problems at low speed in high temperatures.)
Anyhow motor and compressor efficiency are the factors that determine how close to minimum energy used an air conditioner is.
You voltage drop at start is normal from any motor. To not get that you need a bigger electric supply.

Tom
Edit:
I should add I am assuming the house units are scroll compressors.

[THenman]

Additional thought motors can have a soft start added to reduce current draw at start. Not sure if it is a viable option in an RV or if they might even have them already.

Tom

[Durango Dave]

Im thinking there should be some kind of delay between the fan and the AC operation. There does seem to be a problem with both trying to start at the same time. If there was a delay then it might not be so much of a load at one time.

[JFXG]

Originally Posted by Durango Dave

Is turning hot air to cold air such a complicated science that we cant do it cheaply or efficiently now days?

Every time you turn on your air conditioner you're starting a discussion with Isaac Newton, who's been dead for 300 years.

So, the short answer to your question is Yes.

[Isaac-1]

There have been some big changes in automotive air conditioners over the years, particularly in the service life of air conditioner compressors, these days it is common for air conditioner compressors to last the service life of the car, which itself has went up considerably over the years. I have a 2000 model F250 in my driveway with nearly 250,000 miles on the odometer, and it still has its original air conditioning compressor. Compare this to a typical car from the 1970's or even 1980's where you were lucky to get 40,000 miles out of an automotive air conditioning compressor.

[Durango Dave]

Originally Posted by Isaac-1

There have been some big changes in automotive air conditioners over the years, particularly in the service life of air conditioner compressors, these days it is common for air conditioner compressors to last the service life of the car, which itself has went up considerably over the years. I have a 2000 model F250 in my driveway with nearly 250,000 miles on the odometer, and it still has its original air conditioning compressor. Compare this to a typical car from the 1970's or even 1980's where you were lucky to get 40,000 miles out of an automotive air conditioning compressor.

I think part of that improvement was pressure from the environmental people for MFG to make a better product because in the 70's and 80' alot of people were recharging their own AC on their car and releasing the gas into the atmosphere without worring about the environment at all. So now with the longer lasting components and stiffer penalties im sure that action has subsided quite a bit.

[Durango Dave]

Originally Posted by JFXG

Every time you turn on your air conditioner you're starting a discussion with Isaac Newton, who's been dead for 300 years.

So, the short answer to your question is Yes.

When im gone ill have a talk with him and send everyone back his comments on the subject

[THenman]

Originally Posted by Durango Dave

I think part of that improvement was pressure from the environmental people for MFG to make a better product because in the 70's and 80' alot of people were recharging their own AC on their car and releasing the gas into the atmosphere without worring about the environment at all. So now with the longer lasting components and stiffer penalties im sure that action has subsided quite a bit.

Refrigerant changed due to EPA. Also lots of improvement in materials over the years along with improved mfg. Not all was gov. driven and some would just be incidental improvements while reducing costs.

Tom

[bluepill]

Originally Posted by Durango Dave

Im thinking there should be some kind of delay between the fan and the AC operation. There does seem to be a problem with both trying to start at the same time. If there was a delay then it might not be so much of a load at one time.

Newer RV A/C units do just this. Mine has the feature, and my genny loves it.

[Fiesta48]

My 3 roof A/Cs are high efficiency units. Pull only 8 Amps. The front two are Heat Pumps. They only slightly pull more amps at startup causing the lights to barely dim. I'm expecting them to last at least 10 years. I could run all three on 30 amp incoming shore power.
A/Cs have improved. But cleaning them has not.

[UncleBilly]

You can put a "soft start" gizmo in and solve the problem...

[Durango Dave]

do i google soft start gizmo lol what is it actually called please ?

Does it go on the electric panel or does it go on the actual AC

[JFXG]

Originally Posted by Durango Dave

do i google soft start gizmo lol what is it actually called please ?.........

I believe the proper technical term is "big honkin' capacitor".