Electric AC Compressor in Dixie

What's that I said, Bob?

"my profile"? WTF are you talking about?

STILL no answer to that one, Bob?

On May 14, 2:42 pm, "Elmo P. Shagnasty" wrote: . . .

No problem, I understand how easily you are confused.

We were posting about the superior Prius air conditioner compressor in the NHW20 and ZVW30 Prius. Unlike traditional gassers, the Prius do not use a power robbing belt feeding an electric clutch and turning a shaft through a seal in the compressor housing. A seal that is subject to mechanical wear and failure. Instead, the Prius compressors are electrically driven which pays great efficiency and reliability benefits.

The absence of a seal around a spinning shaft elminiates a leak path for refrrigerant. A path that is subject to mechanical wear. It also eliminate the electric clutch, another source of air conditioner failures. Best of all, it is not engine driven so the compressor continues to run off of the traction battery instead of running the engine wasting fuel like a gasser or diesel.

See how much easier it is when you ask nicely, Bob Wilson

Are you saying the Prius does not source its power entirely from gasoline? Is that what you mean by "gasser"?

What source of energy does the Prius use, then?

And you said "the Prius A/C compressor doesn't have any seals". That's way, WAY different than the truth.

Makes one wonder about your pretty charts and graphs.

Thanks for asking as there are several sources that show the superior advantages of the Prius electric compressor. The paper SAE-2004-01-0064 discusses the efficiency in table 4, pp. 10:

Another excellent source is the EPA rule making document:

". . . However, several commenters noted that electric A/C compressors are an enabler to lower leakage rates – beyond the minimum levels we specified - and when this technology is used in conjunction with other leakage-reducing technologies, the resulting system leakage can be lower than the minimum levels we proposed (8.3 g/yr for cars and

"Final Rulemaking to Establish Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards"

So as I pointed out before, the Prius electric air conditioner compressor is clearly superior to the traditional, gasser and diesel versions that used pulleys, belts, electric clutches, shafts and a leaky seal. Completely sealed, they don't have this leak path which the EPA has also recognized. Clearly, it also improved Prius performance that again is so much improved over inefficient gassers and diesels.

Thanks for asking!

Bob Wilson

On May 14, 12:57 am, "Daniel who wants to know" wrote: . . .

I found this excellent write-up in an April 2010 EPA rule analysis:

"2.2.3.4 Compressor Shaft Seal

A major source of refrigerant leakage in automotive A/C systems is the compressor shaft seal. This seal is needed to prevent pressurized refrigerant gasses from escaping the compressor housing. As the load on the A/C system increases, so does the pressure, and the leakage past the seal increases as well. In addition, with a belt-driven A/C compressor, a side load is placed on the compressor shaft by the belt, which can cause the shaft to deflect slightly. The compressor shaft seal must have adequate flexibility to compensate for this deflection, or movement, of the compressor shaft to ensure that the high-pressure refrigerant does not leak past the seal lip and into the atmosphere. When a compressor is static (not running), not only are the system pressures lower, the only side load on the compressor shaft is that from tension on the belt, and leakage past the compressor shaft is at a minimum. However, when the compressor is running, the system pressure is higher and the side load on the compressor shaft is higher (i.e. the side load is proportional to the power required to turn the compressor shaft) - both of which can increase refrigerant leakage past the compressor shaft seal. It is estimated that the rate of refrigerant leakage when a compressor is running can be 20 times that of a static condition.14 Due to the higher leakage rate under running conditions, SAE J2727 assigns a higher level of impact to the compressor shaft seal. In the example shown in the August 2008 version of the J2727 document, the compressor is responsible for 58% of the system refrigerant leakage, and of that 58%, over half of that leakage is due to the shaft seal alone . . ." pp. 75, "Final Rulemaking to Establish Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards Regulatory Impact Analysis", EPA-420-R-10-009, April 2010.

All of our traditional, belt-and-clutch, air conditioner systems have needed refrigerant added after about 8-10 years. We've also had a failed electric clutch with one car too. In contrast, both have been eliminated with the electric compressor.

Bob Wilson

No, Bob, the question was "what do you mean by "gasser" and how is a "gasser" different from the Prius?

The sole source of energy for the Prius is gasoline. How is that different from what you call a "gasser"? How is the Prius not a "gasser"?

The Prius most certainly isn't an electric car.

Well quoting myself from the earlier answer:

"Thanks for asking as there are several sources that show the superior advantages of the Prius electric compressor. The paper SAE-2004-01-0064 discusses the efficiency in table 4, pp. 10:

Assuming you are math illiterate:

Still erecting strawmen I see. So answering in kind by paraphrasing John Cleese from "The Argument" skit:

Cleese: Oh, oh I'm sorry, but this is the superior electric compressor thread. 'Elmo': Look, I CAME HERE FOR AN ARGUMENT, I'm not going to stand ... !!! Cleese: Ah yes, you want another thread, Just start it up. . . . (Under breath) Stupid git!!

Bob Wilson

What do you mean by "gasser"?

List a make and model of car and we'll let you know if it is a gasser.

Bob Wilson

Tell us all what characteristics of a car make it not a "gasser"?

Oh, I get it--you'll just make things up out of thin air when it suits you.

It's a nice fantasy world you live in, Bob.

Excellent choice. It is a hybrid electric, not a 'gasser.'

Next?

Bob Wilson

What differentiates a hybrid electric car, which uses gasoline as its sole source of energy, from a "gasser"?

Do you have another example, make and model, to compare to the Prius?

Bob Wilson

The Prius uses gasoline as its sole source of energy. That makes it a "gasser", right?

A "gasser" uses gasoline--right?

What differentiates a hybrid electric car, which uses gasoline as its sole source of energy, from a "gasser"?

The ability to capture kinetic energy.

Uh, gasoline is not it's sole source of energy. That's why it is a hybrid.

He can look it up in a dictionary if he doesn't understand.

dude...the SOLE source of energy put into the Prius is gasoline.

If I'm wrong, please tell me--what OTHER source of energy does the Prius use?

psssst--the answer isn't "electricity". The MG/battery system is used to MANAGE the energy that's provided by the gasoline. But since no electricity is put into the battery system from the outside--since the ONLY source of energy put into the Prius is gasoline--it's every bit the "gasser" that any other gas-only car is.

How many other Prius owners are so stupid as to think they have an electric car?