# Which window A/C unit should I buy?



## gregzoll (Dec 25, 2006)

First question is, how large is the room that you plan on sticking this into?


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## Dezso3 (Aug 30, 2009)

The first room, for which I'm planning on purchasing one of the mentioned units (all around 5000 BTUs) is less than 100 square feet. The 8000 BTU units would be for a room that is 120 square feet, but has poor insulation and very large, south-facing windows. The 10000 BTU units would be for the third floor, which is roughly 350 square feet. The third floor already has a 10000 BTU unit, but it's a window unit and cannot be installed in the wall, which is why I am planning on purchasing a through-the-wall unit. You can make sure that the square footage, insulation, and exposure to sunlight correspond to the required BTU's by going here: 

http://www.energystar.gov/index.cfm?c=roomac.pr_properly_sized

I have another question. Around what value was the energy efficiency ratio of air conditioners (highest and lowest) that were manufactured more than 20 years ago? I mean of course they were less energy efficient, but just how much less? Please provide a quantitative answer, and not just "they were a lot less energy efficient," because that's obvious.


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## Jim F (Mar 4, 2010)

Without even considering the models my suggestion is to get the one with the least electronic bells and whistles. Those are the first things to go and render an otherwize functioning unit non-functional. Als if they the store offers an extended warranty, probably a good idea.


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## gregzoll (Dec 25, 2006)

Do you rent, or own? If own, why not go with a Split system, or Central Air if already have Forced Air? I have a 1.4 ton in my Living/Dining, and a 8k in both bedrooms. Have to run the fan on the Furnace to push some cool air into the basement. Only big problem is, that once the units die (on average five years), you are better in the long run going with CA or Split system for the costs.



Jim F said:


> Without even considering the models my suggestion is to get the one with the least electronic bells and whistles. Those are the first things to go and render an otherwize functioning unit non-functional. Als if they the store offers an extended warranty, probably a good idea.


Extended warranties are crap, and you are better putting money aside for possible replacement. With the cost of these units being cheaper than they where ten years ago, you can pretty much pay for one out of a paycheck.


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## Jacques (Jul 9, 2008)

i think the Frigd and Kenmore are the same-Fedders? a/c window units are like m/ovens, there's only a few manf. i started using Haire for this old house. been happy-quiet and does the job. the Fedders units i used to use would all start to vibrate and drive me nuts....i have a split system downstairs[radiator heat-no vents]. does a nice job and quiet. had a through the wall for years-loud and exact replacement not available so you end up tearing the sleeve out or getting an 'almost' fits. R22 isn't used anymore..the E rating use to run about[they really play games with this] 7-8ish...if your 120vac unit draws more than 7.5amps you need a dedicated line. for bigger a/c's you're always better off with a 220vac unit. my major concern would be is it quiet and does it do the job..remember better to go smaller than larger[de-humidifing aspect]..contracts on window units are a waste of money.


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## ccarlisle (Jul 2, 2008)

Far too much info to give you without knowing the colour of the walls of each room...L0L

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## Yoyizit (Jul 11, 2008)

Would you repeat the paralysis part? :laughing:


"and the yearly operating cost for the Frigidaire is $85, whereas the Haier's is $89. 
The Frigidaire costs $532, and the Haier costs $398."

So if YRS is the number of years for the cost of ownership for these two to be equal, then 
532 + YRS85 = 398 + YRS89
532 = 398 + YRS4
YRS = (532-398)/4 = 33 yrs
so buy the cheaper one.


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## Dezso3 (Aug 30, 2009)

Does anyone know what type of refrigerants the Frigidaire models FAA055P7A and FRA054AT7 have?


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## gregzoll (Dec 25, 2006)

R-22.


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## Dezso3 (Aug 30, 2009)

*Why do 10,000 BTU units come with 115V and 230V?*

This makes no sense whatsoever. There are 10,000 BTU air conditioning units that come in 115V and 230V. How can you have an A/C with a fixed cooling capacity but with variable voltage? I mean, isn't that like having two incandescent light bulbs: one that emits a certain amount of light at 60 Watts, and another that emits the same amount of light but is, say, 100 Watts?


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## Jim F (Mar 4, 2010)

Dezso3 said:


> This makes no sense whatsoever. There are 10,000 BTU air conditioning units that come in 115V and 230V. How can you have an A/C with a fixed cooling capacity but with variable voltage? I mean, isn't that like having two incandescent light bulbs: one that emits a certain amount of light at 60 Watts, and another that emits the same amount of light but is, say, 100 Watts?


Are you talking about an international version that converts to accommodate other standard voltages? I know the standard voltage in Germany for example is 220, 240 peak. I would assume that the voltage is stepped down at the input from 220 to 110, the units operating voltage. Or maybe the other way around, stepped up. How much A/C do you need for your space? WalMart has the mechanical version in the 5000 BTU for about 15 dollars less that the electrinic version and as I posted earlier, much less problematic from my experiences. I have had mechanical switch AC's that have lasted over 20 years and electronic ones that last only one season.


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## Yoyizit (Jul 11, 2008)

Dezso3 said:


> How can you have an A/C with a fixed cooling capacity but with variable voltage?


Likely the compressor motor winding has a center tap. Correctly phased windings in parallel are for 120, in series are for 240. If you substitute an incand. bulb for each winding you will get the same effect, no phasing necessary.

Computers that can accommodate this range without switching use switch-mode power supplies. The AC gets immediately converted into DC and the circuitry can handle a wide range of DC voltage.


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## Allison1888 (Mar 16, 2008)

*ac units*

I think you can downsize a little on the BTUs, as 8,000 seems too much for a 120 square foot room. We have an 8K one on our first floor and it cools four rooms pretty well...about 600 square feet. I think you could use a 6,000 BTU unit and then do a 5,000 unit for the smallest room. One thing to consider is that they get louder as the BTUs increase. I would try to find an appliance store that has them installed so you can hear how they sound. Also, while I agree you don't want too many options, features like a timer are great if you want it on at bedtime but not all night. I'm not familiar with those models, but we've had Whirlpool, GE and maybe a Frigidaire and they have all been fine. 

One thing to ask is how the water pan drains, as some hold water more than others and you can develop mold.


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## Dezso3 (Aug 30, 2009)

*New A/C Technology*

Friedrich just released a new line of air conditioning units called Kuhl, ones that you could program just like you can program a central air conditioning system because they have programmable thermostats. Friedrich also claims that they provide more comfort than conventional A/C units because they have remote temperature sensors; they are also more energy efficient. Just to give you an example, the Friedrich model SS08M10 with 7900 BTU's has an energy efficiency ratio (EER) of 11.7, and uses about 677 Watts of power, whereas the Kenmore model 75085 with 8000 BTU's has an EER of 9.6 and uses 830 Watts of power. The Friedrich also uses a refrigerant that's more eco-friendly than R-22, which is the R-410A; it does not deplete the ozone layer but is still a very powerful greenhouse gas. Obviously, the biggest dilemma here is price: the Friedrich unit costs about $980, and the Kenmore is only $370. The Friedrich's estimated yearly operating cost is $54, and the Kenmore's is $61. Here's a link to Friedrich's website: http://kuhl.friedrich.com/. Is the Friedrich worth the extra price?


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## Yoyizit (Jul 11, 2008)

Dezso3 said:


> the Friedrich unit costs about $980, and the Kenmore is only $370.
> Is the Friedrich worth the extra price?


If the Mean Time Between Failures, MTBF, for the 'Cool' unit is 2.6x longer than the Kenmore, with comparable replacement part prices, then maybe.

Maybe buying something like this is a status symbol for some people.


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