A/C--Is It Really Cooling?

I have a Whirlpool A/C that I bought two years ago that fits in a window. Consumer Reports gave it a terrific rating. I started using it this summer in a 10 by 10' room and it seems like it's cooling me pretty well while I'm at a desk. I have a thermometer in the room that doesn't seem to move from 84 degrees after 30-40 minutes of cooling. What's up?
--
Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
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On Wed, 27 Jul 2005 05:34:44 GMT, "W. Watson"

Three things, at least:
You've probably got cool air blowing on you, it takes a couple of hours for a room to stabilize, and at least you are dehumidifying the air, so it feels cooler even without dropping the temp.
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--
-john
wide-open at throttle dot info
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Yet another factor- location in house. If you're cooling a room that has easy airflow access to solar-heated areas below, guess what?
Location, location, location. To include latitude & longitude.
HTH, J
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on a side note... can some one really quick give me some figures..
my house has 2 AC units a 4 ton and a 2 Ton... How much power do they draw. when they run? the 4 ton is for the 1 st floor 2/3 of the house, and the 2 ton is for the second floor 1/3rd of the house.. The reason I am asking is that, I found a photograph of the previous owners. who had put a window A/c in the master bedroom.. So that got me thinking.. is it economical to put it in the master bedroom and run it all night, while the 4 TON A/C is off, as it is unecessarily cooling the entire 1st floor ( ie, kitchen.. , dining,,.etc)
I do have a 5000 btu window , ac., which , if I am not mistaken, consumes. 550W.
assuming it runs for full 8 hours.. that is 4.4 kwh units.. Now my 4 TON runs atleast 4 hours. each night.. how much does that translate into. ? But it does keep the kitchen.. living.. dining.. all cool. . when I wake up in the morning
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snipped-for-privacy@hotmail.com wrote:

The 5000-Btu/hr window jammer should cool the bedroom during sleeping hours with no problem. It will probably (?) only run half to one third of the nighttime hours, or less.
Does the 4-ton cool the Master bedroom, or does the 2-ton cool it? Does the 2-ton handle the upstairs heatload okay?
A 4-ton 12-SEER ComfortMaker pulls around 4761-watts, plus the indoor furnace blower will pull at least 575-additional-watts. The 2-ton 12-SEER pulls around 2659-watts plus 575-watts for cooling coil blower motor.
I am betting the first floor 4-ton is considerably oversized. How well it is cooling doesn't mean a thing, as many oversized units are not delivering anywhere near their rated capacity. How big is your home? Eight foot ceilings? Have a manual J done so you know what your home calls for!
When both your central units are running they "could be pulling around" 8570-watts. That is a lot of juice! How much on average do those central units run?
For your own benefit, read both of the linked pages below. - udarrell http://www.udarrell.com/airconditioner_current_temperature_btuh_charting.html
--
Factors in the Correct Sizing of Residential Air Conditioning Systems -
Recommended Procedures for Proper Duct Sizing of Residential Air Conditioning
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uDarrell, thanks a lot for your links.. They are informative. I will see if I can get a Manual J done on my house. But for now. putting the Window Jammer will definitely save me $$..just for the peak summer months in TX..
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Well, I guess you could look at your service entrance meter and figure it out...
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How large a room? How large an AC? Temperature outside and sun load?
To see if it is cooling put a thermometer on the intake and another on the outlet and see what the differential is.
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Litttle thing called thermal dynamics.... And of course, lack of information from you to be able to tell you, but in a nutshell, window units suck and people seem to think that if consumer reports said they are good, any size one will work.

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On Thu, 28 Jul 2005 01:45:24 -0400, "Carolina Breeze HVAC"

Care to elaborate?
In a nutshell, I think SUV's suck, but many soccer moms will beg to differ.
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--
-john
wide-open at throttle dot info
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wrote:

Nope......
Soccer moms blow.....and it's them mini-vans that suck !!!
--
SVL




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wrote:

Sure: No one knows how to size em right, they think that if they get that little 99$ one at Lowes, its gonna work forever, none of the sizing charts, if you want to call them that state anything much more than room size..no insulation values, nothing.. They are noisy, vibrate too much and are heavy..lol...

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I always regarded you as a knowledgeable person, but is itseems you are also an elitist.
In many climates it is plain silly to spend $10,000 for central AC when a window shaker works for the 10 or 20 days a year it is really hot.
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wrote in message

Cripes man... 10 grand for a central air units really pushing the envelope right now....well, maybe not, but still, when you can get a package unit, with duct installed in the 12SEER 3 ton range for under $3000 in some places, well, it just makes sense to get one. Window shakers have their place. And ironicaly enough, I just had to pull one and reinstall a new one for a resturant that is in a building that central AC is all but impossible due to the landlord. The landlord lives above the cafe, and the clothing store and THEY have central air, but will not allow them below to have it.
The problem I have and I think you missed it, and if you did, its partially my fault..something about loosing a sense of humor when its 113F out and everyone thinks you are superman for 48 hours, is that when you, the average person, goes to Lowes, Home Depot, or gasp..Wally World, you have no idea what you are looking at NORMALLY, in the sense of what will this do REALLY? You can take two 21,000BTU units, different makes and different air flow designs, and while both should remove 21K one might have better airflow than the other, makig it seem that its cooling faster, altho, both are indeed removing the same amount of heat. Then, you have the sizing issue...some places only need a few thousand BTUs while others will need much more. Many people just look at the price, and maybe, thats maybe the little sizing chart that they might, or might not have at the store. Granted, not many people can or will take the time to get a load calc done for a window unit, but sometimes, it can be the difference of it working, and not working to your satisfaction. Point being, IF you didnt size it right, and IF its worked fine till the temps hit 90+F, then if it seems not to be cooling right, its not the units fault. They still suck tho..lol..after lifting that 2.5ton heat pump unit into that window myself, I would have rather moved a 5 ton heat pump package unit solo.....and yes..I did on Sat..LOL...

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Maybe you mean the room has significant thermal mass... 35 minutes at 5000 Btu/h is 2917 Btu, enough to cool 3 55 gallon water drums or 2917 ft^2 of 1/2" drywall 2 F.

Perhaps W. Watson has 2 dozen water drums in the room :-)
Nick
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Nick, He may have a defective thermometer :-)
Watson did not say what size window unit he had, what size & how many windows were there, if the room was insulated or how well, or how hot it was outside (or how many drums of water or other stuff was in the room.
We need more information.
Stretch
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True. Does it always read 84 F?

I'm thinking most window units are at least 5K Btu/h, and windows and insulation aren't a big factor 30-40 mins after the AC is initially turned on, starting with indoor and outdoor temps in equilibrium.

Lots of mass with a small time constant (eg lots of drywall) could initially keep room air warmer, but a 55 gallon drum with a 12 hour time constant wouldn't do that.

Agreed. Maybe W. Watson has a huge unshaded west window and only turns on the AC when sun begins to shine in.
Nick
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snipped-for-privacy@ece.villanova.edu wrote:

Well, this thread certainly wandered a bit since I posted it about 12 hours ago. No one had anything to say about the war in Iraq, global warming, AIDS, the West Nile virus.
Despite all the hand wringing on CR and other matters, the unit does the job. It keeps me cool despite 95 degree outdoor temps right outside the room. The the room is one of three rooms in a building well detached from our house. There are no barrels of water nearby. The room has a concrete floor (did that raise a few eyebrows), and otherwise is constructed like a conventional house--insulation, wallboard, two 2 by 3' windows, and three doors. One door goes to the outside. Another goes to a similar room, and the other goes to a room that has much less insulation than the other two. In fact, this room has a *metal* dome on it. In fact, it is an observatory (as in astronomy). The door between it and the room I have the A/C is rather thin and uninsulated. I wonder where the thread will go now? :-) None of these rooms is in any shade.
--
Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
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its takes time to cool things down... Also depends on the size of the unit. If its undersized it can take an eternity to cool things down.
Make sure to keep that door shut too!
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