# High efficiency air conditioners



## drhowarddrfine (Mar 9, 2011)

Talk about off topic 

Just got our "energy report" from the electric company comparing last year's electricity usage to the previous year. In late April of last year, we took advantage of state and federal tax credits plus manufacturer's rebate to replace our aging air conditioner with a high efficiency one. All that made it close to the cost of a regular air conditioner. The report shows that, even though the weather was warmer by 2-6 degrees F month to month, our electricity usage was down two percent.

The bar chart shows the immediate savings when we switched over. We run our business out of the house and are somewhat heavy electric users. That worked out to a savings of 8 cents per day. About $30 per year. The actual usage was 19,792kWh compared to 20,188kWh. Once again, that was for the year but the AC was installed in late April.

So the payback does not seem to be worth it if you have to pay full price without the tax benefits and especially since we decided to sell the house. Don't take that as an anti-"save the planet" stand. I'm sure our savings would have been more if the temperatures were the same but, even if doubled, that's only $60 per year.


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## Pushrod (Mar 9, 2011)

Indeed most of those types of things are not worth it from an economic standpoint unless there's incentives. It may not be so great for the environment either; when you replace something, the old one doesn't just vanish.

It takes about 10 years for a car to pollute as much on the road than it did when it was being built. That said, people selling 5-year old cars to get a new, "cleaner" one are doing the earth (and their wallets) exactly zero favours.


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## Crivens (Sep 21, 2011)

Pushrod said:
			
		

> It takes about 10 years for a car to pollute as much on the road than it did when it was being built. That said, people selling 5-year old cars to get a new, "cleaner" one are doing the earth (and their wallets) exactly zero favours.



Amen! It is even below zero.

The same goes for these "environment zones" in some cities. I can not drive into Berlin for example because my 10 year old car is not "clean" enough - but takes about 4l/100km. The butt-ugly SUV which guzzles 3 times that is OK, but has less pasanger space.

What I would like to know w.r.t. the air condition: how much electricity was spent building the new one, and how long would it take to amortize that?

Which reminds me - there was some measurement what took more juice: keeping the machine in S3 for the time you do not work or shutdown/reboot it. Strangely, the S3 seems to win.


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## drhowarddrfine (Sep 21, 2011)

Crivens said:
			
		

> What I would like to know w.r.t. the air condition: how much electricity was spent building the new one


It doesn't matter. It had to be built.





> and how long would it take to amortize that?


It doesn't matter. The old one had to be replaced.

The point was, the new one uses far less electricity than the old one.


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## mix_room (Sep 22, 2011)

Crivens said:
			
		

> The same goes for these "environment zones" in some cities. I can not drive into Berlin for example because my 10 year old car is not "clean" enough - but takes about 4l/100km. The butt-ugly SUV which guzzles 3 times that is OK, but has less pasanger space.



Fuel consumption is only one part of the equation though. One of the biggest problems with older cars was the exhaust of NOx. This has, with modern cars, largely been solved to a point where the exhaust of a modern car can in extreme cases contain LESS pollutants than the intake air. Now consider why your old car which consumes 4l/100km, but produces (for discussion purposes) 100 units of other, primarily local, pollutants. A modern SUV which consumes 16l/100km might only produce 25 units of other pollutants. (Yours consumes 1/4 of the fuel, but 4 times as much pollutants) Which car is cleaner, and which would you rather have driving around your neighbourhood? CO2 is a pollutant which has primarily a global effect while the NOx and SOx pollutants have a very strong local effect.


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## xibo (Sep 22, 2011)

Or the automobile industry lobbies have just been doing their work well, while the government is trying to sell it off as environmental protection. Why else do you need to be "clean" to drive through a city but can afford to be "dirty" while driving through smaller towns, or even nature protected areas?


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## drhowarddrfine (Sep 22, 2011)

xibo said:
			
		

> Why else do you need to be "clean" to drive through a city


Cause that's where the dirt is.


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## DutchDaemon (Sep 22, 2011)

_Concentration_ of pollutants and microscopic dust particles is the operative word there.


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## Crivens (Sep 22, 2011)

Well, when president shrub was visiting a city in germany they blocked off the center for 3 days - with 3 days of no cars and no effect on dust or soot. Also, beekeepers are returning to the cities because their bees stay more healty there than in the country. Thas has to do with GM crops, so that is partly another story.

When microscopic soot or dust is of interest, it is often ignored that the microdust from tires and brakes is the same regardless of engine type, but is increasing with vehicle weight. So here the SUV has the problem of the bigger weight which has to be accelerated and stopped again. And yes, I call modern SUVs butt-ugly because DD would not approve of the more appropriate vocabulary, I fear


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