Are all 8000BTU Window AC created equal?

Greetings:

I am in a first floor of a two floor appartment complex. All the room is directly under an isolated roof and my 4/5 years 8000 BTU Whirlpool window AC is unable to cool the living room (25ft long x 13 ft wide x 7.5 ft height) in a hot summer time. Are all 8000 BTU Window AC created equal regardless manufacture and other parameter? If not, what make one be cooler and more efficient than other? Can someone please recommend the best one of its kind in the 8000 BTU category? Advance thanks for any kind of help.

Well, I can't recommend the best one, but as long as they work for me, I can't complain. And no, not all a/c's are created equal. If memory serves me correctly, the btu rating is calculated from design, not by practical application on every a/c. Only some are checked for spec's before they leave the factory.

Has anyone cut down and trees near your living room? Or did any significant landscaping? Do your windows leak outside air?

Do you hear water splashing when the a/c is running?

About your window A/C....have you had it professionally cleaned? What I mean is taken apart, alkalai used on the evaporator coils (inside one's) and acid used on the condensing coils (outside one's).

Then has anyone checked the amperage draw on the fan and compressor to make sure things are within specifications?

Has the tech checked to see if the fan can be lubricated? If it can, did the tech lubricate it with the proper amount and kind of oil?

About 25% of the window a/c's I work on only need to be cleaned, 50% need both cleaning and charging, and the rest are too bad off to economically repair.

If a tech did charge your a/c, did he perform a 'balance' check on the evaporator to ensure you have the proper charge? The refrigerant stickers posted on both refrigerators (domestic) and window a/c's are FREQUENTLY inaccurate. Typically, the manufacturers run them a little low to maintain designed obsolescense.

Zolar

Thanks Zolar for your advice and help.
I will try to answer as much as possible to your question:
1. Has anyone cut down and trees near your living room? No

2. did any significant landscaping?
They do mawn the lawn and blow once every two week or so. However, I am off the ground by at least 8 to 10ft height.

3. Do your windows leak outside air?
It certainly is since no window AC fit perfectly to all type of window. However I think I've put enough foam around the unit to compensate as much as possible any leak.

4. Do you hear water splashing when the a/c is running? No

5. About your window A/C....have you had it professionally cleaned? What I mean is taken apart, alkalai used on the evaporator coils (inside one's) and acid used on the condensing coils (outside one's).
No, I don't understand the need for this cleaning. The AC is intall in a clean area, where there is no leaves or other debris could fall inside. There is no tree or anything around the AC. Beside, I've take a look inside and it doesn't look as dirty as other unit that I've seen when going to a garage sale.

6. Then has anyone checked the amperage draw on the fan and compressor to make sure things are within specifications?

7. Has the tech checked to see if the fan can be lubricated? If it can, did the tech lubricate it with the proper amount and kind of oil?

No, I don't understand the need for question 6 & 7 either.

Anyway, the unit seems to produce not enough cold air already when I first bought it. Based on my experience with car AC as an user, I notice that some car AC produce cooler air than other. Therefore I assume that it is the same for household. Some manufacture may build better unit than other. Unfortunately, it is impossible to test an AC before you buy.

Your time and help is greatly appreciated.

The reason to prefessionally clean an a/c is to ensure that accumulated dirt on the back side of the evaporator and between the coils is removed - this ensures better air flow. The reason to clean the outside is to remove debris, check components, and de-oxidize the condensing coil fins.
In both instances, you cannot visually inspect the unit without first disassembling it.

If you choose to properly clean the unit yourself, please be sure you do it safely. Both the acid and alkalai can cause serious problems to people, pets, and property if not handled correctly. Also, avoid using too strong a stream of water when rinsing. If any of the fins are bent over or flattened out, you would have to either get a fin comb or use a small regular screwdriver to straighten them out. Be very gentle if you use the screwdriver.

Odds are, it needs to be properly cleaned and topped off.

Feel free to email me if desired.

By the way, 8000 btu's is kinda low for the size of the room you are trying to cool.

Also, any kids running in and out of the room? Have you installed anything new like a big TV set/hight powered stereo, or other heat producing items in the room?
Have you changed curtains or left them open more than you used to?

All these factors and many more can contribute to ineffective cooling.

Regarding automobiles....

Much depends on the age of the vehicle, the engine size, vehicle size, and type of refrigerant used.
Comparing Buick's to BMW's is like apples to oranges...not quite the same.

FYI...ALL systems that contain refrigerant leak. It's the rate of the leak that determines how long and how well the item will work for a given design.

I like your advise Zolar, it's clean and precise.

You sound like you take pride in your work and have a good knowledge.

zolar1:
Thank you for your clarification. I thought it was a simple matter AC but it isn't in fact. Too many parameter come into consideration to find out if the unit works on promise. My dad suggest that instead of buying a big 10,000 BTU or so, I should buy two 5000BTU and install it in two seperate location. One blowing in the 13ft wide direction and the other one blowing in the 25 ft long. What do you thing about this idea?

By the way, you make a good point when mentioning about heat sources such as TV, Receivers etc. I do have a 36" TV, 2 computer with 2 21" monitor (occasionally both of them is turned on at the same time, an halogen lamp with 300W bulb and finally no kids.

just a thought instead of putting in more window a/c's you might want to look into a ductless a/c. the do not block the windows and they are very quiet. they range from 6000btu up to 36000btu and work very good.

Thanks for your suggestion.
My sister has one unit and I don't like it. It's bulky, the cooling effect is not efficient and she have to empty the water container every now and then depends on how much humidity is on the air.

i'm actually talking about a ductless split system. the evaporator is hung on the wall and the condensing unit sits outside. it drains it condinsate outside. the evaporator is 40in. long 11in.high8in in depth. for a 12000btu

Sorry for mistaking. I thought what you are referring to is the mobile unit which has a duct attach to the window to exhaust the hot air.

Thanks you for the compliment barry, and you're welcome pwanghk.

My credentials aren't very long at all, in fact, most of my experience comes from 2 things -
First - just a lucky guesser, and
Second - a natural apptitude for mechanical/electrical things.

I am 95% self taught at this point in time. I listen to others talk, read posts I can't even begin to comprehend yet, and ask lots of questions.

But nothing will prevent me from my goals. I like this trade so far, even the idiosynchrocies (spelling?) of some of the equipment I have worked on. I take a practical viewpoint of problems, and look at those problems in a round-about way. I try to rule out the obvious whenever possible while troubleshooting.

Regarding the A/C situation....2-5000BTU a/c's would consume more power than a single 10,000 one. This is beacuse the rate of energy lost is proportional to the number of mechanical parts used to do the job.

Continued.........

The 10K BTU a/c would most likely be the best choice for the job, and can save you money at the same time.

I do have 2 good suggestions before you buy one -
Have someone look at your existing a/c and service it if necessary, and install a 5 blade 52" ceiling fan (not a cheap one either).

Not only would you benefit from the savings in energy (because the air movement would make you 'feel' cooler and you could turn up the a/c a bit) you would cut the noise level a lot. 2 jackhammering compressors has just got to be nerve racking.

Ask yourself this:
Did my a/c keep me cool a few years ago? Why isn't it doing the job now? What can I do to remedy this problem without taking a second mortgage to either fix my old one or buy a new one?

Continued (again - sheesh!)

I personally prefer to fix my old one if I can. The new one's just aren't as high quality as the old one's were.

Many times people toss out a/c's for various reasons. Pick up a few of them and see how they are made, see how the parts look.
I pick up a/c's whether they work or not, swap parts if necessary, reassemble, clean, charge, and resell them.

The apartment 'slide-in' units (through the wall, 220vac, 8500-12000 btu's), when fixed, retail (reconditioned) for around $150-$250 each. The parts cost me about $30-$50.

Contact your locak used appliance dealer and see if they offer a/c service, assuming you can't do the work yourself.

Ask them if they recharge the unit, how much is the cost, including the proper cleaning of the coils. Ask them what kind of service valve are they going to use?
If they use the cheap one's and don't braze the fitting shut when done, you'll be right back again next year to have it recharged again.

Continued...sigh

I test, tap, recover, vacuum overnight, clean, recharge, balance, and reseal (braze) the system. At best, you should be able to use one of mine for about the same number of years yours worked before you needed service.

That's the difference between me and a cheap hack of a repairman. I like the old philosophy - FIX IT TO LAST!

Zolar

PS I have begun experimenting with custom making my own heat exchangers. I make them for domestic refrigerators and they work well, saving between 15% and 30% on electricity used to run the compressor.

I'll 'engineer' one for window a/c's that should, in theory, not only save power, but should be colder.

Even brazing the high and low side lines together for a few inches helps some.

And yes to all the real engineers - I am aware of what happens when you have one that's too big. (been there, done that with 2 of my prototypes LOL)

Zolar: in response to your suggestion.

I am in a renting appartment therefore, I can't do what ever I want especially install a ceiling fan.
As for the 10K btu, it is too heavy for myself to lift it up and put it to the window. I think I am going to go back to my 8 or 9K btu units solution though.
My units doesn't work well since I've bought it a couple years ago. I don't know if it is due to the manufacture components or something else. The unit is as big a 10~12K btu in comparison to a few 8~9K that I've just seen in a local store.
Local A/C service charge $75 for service mine (recharging and cleaning, will be more if they find something else). I am willing to give it try. Unfortunately, I am too scare to be ripped off since I have no clue the proper procedure and what component the tech will use. Also, I have take a day off (wich will cost me ~$200). With all this hassle, an uncertain result and the price is almost the same if I buy a new one. I think I will opt for buying a new units and give the old one to friends or relative.
Anyway, your time and help is greatly appreciated.

Your 8000btu unit is probably ok, just not big enough to do the job. You could just buy another 8000btu unit and put it in a different window. Run them both on a hot day. And you might want to take the unit outside and spray both of the coils with water. Try not to bend the fins. Let it dry thoroughly before you bring it back inside. This is not the best way to clean it, but it will help.

Here in Cincinnati, Ohio, appliance service can be done on Saturday's with no extra charge.

What part of the USA are you in?
$75 seems to be in the ballpark for a clean and service - I usually charge $25 for the cleaning + $65 for the recharge with a minimum charge of $35 no matter what I do.
A service person should run the unit and check the temperatures to see how far off your unit might be. Typical evaporator temperature going both in and out of the evaporator should be within 5-9 degrees F of each other. If it's more than that, definately have it cleaned and rechecked.

You could go to a local supply house and buy a can of no-rinse coil cleaner and liberally spray the evaporator and condensor coils.

Sorry I couldn't have helped you more.

Zolar

Thanks you so much Zolar1. On the contrary your are helping me enormously to see all the option before I reach my wallet. Anyway, I don't know about Cincinnati Ohio. But in here NJ, I think you'd rather be knowledgeable about everything that you need to be serviced. Otherwise you can be easily screwed. There certainly are honest techies out there; however, to find one is the whole issue. You don't know anybody from the State of NJ by any chance? If so your reference would be greatly appreciated.

Not mentioned is where your home is located. In the South USA a 8000 Btu Window unit is way too small for your area to become cool on hot days. If your in the 60's at nite (Canada or Montana...) a lot it mite be ok. COnsult the pros in your area for a rule of thub on the heat load gain of a room like yours.

Also the 300W halogen lamp ... I believe its taking away 1000 BTUs of your cooling. 1 watt equals 3.41 BTUS I think. So now your 8000 Btu Window unit is only 7000.

Change your lamp to a floursent type. Has good a lite and way less heat.

pwanghk, I just thought of something. Why couldn't you buy a pedestal fan and use it to circulate the air in the room?
You would 'feel' cooler anyway, and for less money.

And yes, there are MANY dishonest servicemen out there, and here in cincinnati. I am one of the rare one's that actually cares about my customers. I figure if I can save them a little money by doing what's needed and no more (except cleaning as a preventative measure), they will remember me and I should get plenty of referrals.

I know 3 out of 4 used appliance stores within 1/2 mile of me rob people daily. It's the used appliance stores that normally take care of the small stuff. the bigger guys are all headed for the money with the big stuff, and usually won't fool with small appliances.