Expert: David Powner - 2/2/2006

Question
Dear David,
I have a question for you.  You see below part of an E-mail that my friend sent me about calculating EER. I have everything except the AMPS put out by my Portable Room Air Conditioner.  i guestimated 6AMPS by the way itis running.  But need to know how to get the watts that my Portable A/C is putting out when running.  What do I use and where do i take the reading for th eamperage of my A/C.  Once I have it I can compare it to the EER they claim for this machine of their web-site.  I want to use use this to compare the machines true efficiency

I appreciate your help.
God Bless,
Don Crosby JR.
-------------------
Hey DonHo,

EER is the energy efficiency ratio:

EER = output / input

If you buy an air conditioner with a high EER (Energy Efficiency Ratio),
you can save on your electric bill. Energy Star-qualified air
conditioners use less electricity than conventional models. Some utility
companies also offer rebates for owners of Energy Star products,
potentially saving you even more money.

EER ratings measure the amount of cooling provided by an air
conditioning unit against the size of, and energy used by, that unit.
The higher the rating, the more efficient the unit, and the more you'll
end up saving on your energy bill. Most EER ratings fall between 8.0 and
11.0.

13,000 Btu/hr is claimed
10 amp at 115 volts = 1150 watts, input (MAXIMUM - 10 amp circuit)
6 amps at 115 volts = 690 watts, input (MEASURED value)
1 btu = 0.3 watt hours (or 1 watt hour = 3.33 btu's)
1 watt second = 1 joules
1 btu = 1055 joules
1 watt hour = 3,600 joules = 3.4 btu

At 100% capacity (10 amps)
1,150 watts for 1 hr = 3,830 btu's

At 6 amps
690 watts for 1 hr = 2,298 btu's

EER rating is output/input energy (assuming 6 amps measured)
EER = 13,000/(2,298) = 5.7

Seems pretty low (poor efficiency - IF 6 AMPS WAS MEASURED, WHICH YOU
ARE GOING TO CHECK
Per below 11.3 EER is claimed.


From the Fujitronics Web-site
----------------------
Model: FA-1300
BTU: 13000
Recommended room size: 400 square feet
EER: 11.3
Controls: Electronic
Noise level: 53 dB
Modes: Portable ac, fan, dehumidifier
Condensate: All pumped out hose
Number of hoses: 2
Hose length: 5'
Diameter of exhaust hose: 5"
Window kit max.: 48"
Voltage: 115v
Amperage: 10 Amps



-------------------------
Followup To
Question -
Dear David.
I appreciate your help.  Somethings that I did not mention.  They claim that the machine does 84 pints per day de-humidification. They assured me that this machine would do the 20-30% humidity that I needed.  the problem there is no way to compare %humidty to pints per day, so thay can not make that claim.  Another thing they say set it to 70 and you will get 70.  On a warmer day I need to set it to  60 to get it in the low 70's  This makes me thing something is not right.  As far as everything goes. nothhing has changed much, and the conditons are still the same.  The machines are th esame basic set up, 1-2 hoses filtered out the window mount as was before where I only had on hose. You say de-humidification and stuffines go hand in hand, is that because you are removing humidity. My set up is this.  the A/C venting out the window, right behind it the de-humidifier.  

Since your E-mail I discovere th eitem below.  It is a window guard.  it filters out 95% of the stuff in the air, while letting fresh air in.  My thinking is it will undo the stuffiness, but it will let some moisture back in which the dehumidier will take care of.  I used this for three years before I got my A/C and it worked well.  How will thios set up work,. will it keep the room less stuffy.

God Bless,
Don Crosby Jr.
 
.

http://www.allergyasthmatech.com/allergyasthmatech/product-detail.asp?ItemID=137

If you're sensitive to pollens and molds and want to enjoy an open window, our Window Guards are just for you. Pollen, dust and mold are kept outdoors by this unique Window Guard. Its patented triple-filtering air baffles allow only clean, fresh air to enter. It can be used in any season since it is not affected by rain, snow or high winds. Its sturdy aluminum frame makes it easy to install in any double-hung casement window. To clean, just rinse it off under running tap water. The small Window Guard is 7" high and adjusts to fit any window 20" to 36" wide. The large Window Guard is 11" high and fits any window 24" to 44" wide.



-------------------------
Followup To
Question -
Dear David,
From reading your area of expertise, it seems like you may be able to help me with my dilema.  I live in Westminster CA, right on the border of Huntington Beach.  My second floor 10x10 faces the beach, as a result my room is always 10 degrees hotter than the rest of the house.  For 8 years I had a Delonghi PAC290 Portable room Air Conditioner and never had a stuffy room problems.  My current machine the Fujitronic FA1300 does not seem to perform very well, as a result it leaves my room kind of stuffy.  I can open a window, but it has been a bad pollen season, so that is not an option as I have allergies. I must also keep the door closed to keep the stuff from the rest of the house from coming in.  In my room besided the air conditioner, i have a ceiling fan, air cleaner, cool mist humidifier and de-humidifier.  Down stair in th eliving room I have a ceiling fan.

I was wondering if you had any advice on keeping my room less stuffy.  Would running the ceiling fan down stair all the time help at all.  i appreciate your help as I am tired of waking up in a stuffy room.

God Bless,
Don Crosby jr
Answer -
Hi Don..

At first glance, I am puzzled. The Fujitronic seems to be about 50% more powerful than the Delonghi, so I would wonder whether the new unit is faulty.

Did you have the other accessories when you had the Delonghi? Has anything else in the equation changed (apart from global warming)?

Stuffiness & Dehumidifiers go together - is it essential to have it? - I would have expected the Fujitronic to be more than adequate in dealing with the humidity.

I'm not familiar with either piece of kit, but I think they both use the same refrigerant, which again leads me to think there may be a fault on that side.

So my suggestion is to have the unit checked for faults.

Is it possible to hire another identical model for a short time to confirm the unit works properly?

I really don't know what else to suggest, as the specification says it ought to perform better purely from a mathematical standpoint.

Dave Powner
Answer -
I guess they mean up to 84 pints where the humidity is at saturation. You can get a temperature humidity gauge for a few dollars.

Living in the UK, I have no comprehension of your specific conditions, but of course you need some level of humidity.

Bodily comfort is related to both temperature & humidity - evaporation of sweat has a cooling effect, so the higher the humidity, the less sweat is evaporated.

I would suggest you visit http://www.csgnetwork.com/canhumidexcalc.html, where you will find the humidex calculator.

You will see that different combinations of temperature & humidity have different effects, and that you should aim to get a humidex of 29 or less to ensure comfort.

You can then experiment with different settings to achieve the desired result.  

Dave Powner

Answer
To measure the amperage is technically very simple. In practice, for most people, it is not so.
You will either need an ammeter(amp-meter) that you can connect in line with your electricity supply, or a clamp meter that encircles the live feed. Neither of which you are likely to have.
Incidentally, your device does not "put out" amps - it consumes electricity measured in watts. Watts = Volts x Amps. 115 volts x 6 amps = 690 watts
With your friend's data, you thenhaveall you require to do the maths