High efficiency or not

Lets talk efficiency what through the eyes of a refrigeration person would be considered as high efficiency not the numbers listed by the MFG but what truly would be a reason for high efficiency in a residential A/C unit.

What would be your take on the pic below could it be a high efficiency and why or would it be low efficiency and why.

First off…

What does the manufacturer recommend for clearances?

Where’s the pad?

Where’s the Emergency shut-off?

First sentence nothing to do with efficiency:D

Second sentence nothing to do with efficiency:D

Third sentence nothing to do with efficiency:D

OK, before I answer, I’d like answers…

You’re efficient!:smiley:

I really don’t know about the other…it works or it doesn’t.

u guys are efficiently funny

Actualy a more efficient way to have said it would have been;

“Neither the first, second, or thrid sentence have anything to do with efficiency”:slight_smile:

But seriously, How is one supposed to tell from that photo or any photo what the efficieny is? How do we even know if the plenum coil is properly matched? The current charge? The stated efficiency? etc, etc.

Oh no…Not anohter of Charley B.'s . **NOW CLASS :wink:

**Go for it Charlie, teach these Cretans something. If that’s possible.:-):slight_smile:

Just shut up Mike I’m having some fun here answer the question:D :smiley:

You can tell from down at the end of the next block.

Ok fair enough:

The disconnect was above just out of the pic

The unit is setting on concrete not a heat pump not required to be raised.

Yes the unit was a little close to the exterior wall had a hard time reading the data plate.If it had been moved out any further would of been blocking the sidewalk that traveled back under the raised deck.

Does Size matter?:stuck_out_tongue:

Just what size do you think that unit was:D It was an infant

Looks small for OK:D

In all seriousness besides the seer rating , the good tech will see if the size of the unit is matched properly to the space it must cool.
To small and it will over work.
Too large and it will burn the compresser with to many starts and stops.
Is the ducting sealed properly.?
Hows the house insulation.?
Are thereturns placed in proper locations and are they balanced to the vents(output)
It is a lot of things.
Me I just turn it on. lol

The energy ratings of air conditioners are based on how many Btu’s (heat) per hour the unit can remove for each watt hour of power it draws.

For central air conditioners, the efficiency rating is called the Seasonal Energy Efficiency Ratio, or SEER.

The most efficient air conditioners are listed by size and efficiency in the Consumer Guide to Home Energy Savings, published by the American Council for an Energy-Efficient Economy.

National appliance minimum standards for central air conditioners require a SEER between 8.9 and 10.0, depending on when the unit was manufactured.

To determine the approximate SEER of an existing CAC find the model number and the manufacturer from the nameplate on the outdoor unit and contact a local dealer and ask them to look it up for you.

Sizing is a very important consideration to achieve comfort and minimize energy cost when selecting new a/c equipment.

The cooling comfort is provided by reducing air temperature and removing humidity. An A/C that runs all the time isn’t necessarily sized correctly. It could be oversized, and straining to overcome maintenance, repair or adjustment problems. Or it could be undersized.

The preceeding is not meant to undermine the intelligence of others but rather to assist those who may not have known as much. :smiley: Oh well!


The preceeding is not meant to undermine the intelligence of others but rather to assist those who may not have known as much. :grin: Oh well!

** ???**

Ahh, you know how things get twisted around here sometimes, just wanted to clarify things. :smiley: LOL!!!

Hugs and kisses!!!


This is true no argument from me but my intent was to discuss efficiency not on the MFG specs or name plate but what is basically visible to the HI. Yes condensers are rated on their ability to remove BTU’s per hour but that varies with the outside ambient and I will explain that later.

The reason I even bring this up was the physical size of the unit in the pic even surprised me was even smaller than it looks in the pic. It was a 2 ton carrier bottom of the line builders model junk. It was serving an added on bedroom on a 4K plus home.

When I think of high efficiency I think very large condenser area with the capacity to hold large volumes of Freon. And my take on this not being a design engineer just know what I have observed in the field. The Ideal pressure on a condenser with an outside ambient at say 85 to 90 degrees is 250 PSI on the high side and 65 PSI on the low side. As the outside ambient climbs above the 95 degree mark the head pressure or highside starts to climb also. Pressure temp relationship is greatly affected at this level. The higher the head PSI the higher the suction PSI.

Basically what I am saying the units with a large condenser moving more air across the condenser will be more efficient due to the amount of heat removed while changing the hot gas to a liquid within the condenser the cooler the liquid traveling back to the A-coil has a definite effect on the vapor pressure leaving the A-coil.

For an example lets say the liquid pressure leaving the condenser is at 350 to 400 PSI the suction pressure is going to be near 80 to 85 PSI the ability to cool a home at those temps are squat the unit will be in a continuous run mode and the inside temp will climb accordingly. OK lets put some dog hair and grass clippings on the fins of the condenser and watch the efficiency of the unit go down the creek with the additional head pressure temp increase.

Bottom line; efficiency is directly tied to the ability to control and manage the head pressure and suction pressure of the unit. Size of the condenser major factor. Size Mike Size:D No I am not suggesting HI use gages simply touch and feel will tell you all you need to know if you understand the freon flow pattern in a system where it is a hot gas where it is a warm liquid and where it is a cool vapor. If you don’t have at least this knowledge you as an HI should learn it Just Ask one of the many knowledgeable guys available on this board and am sure you will have answer


Looks too small to be a Hi efficiency unit.