High efficiency or not

[jrivera]

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. Oh well!

Mic

[Bob Elliott]

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

??????

[jrivera]

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

Hugs and kisses!!!

Mic

[Charley L. Bottger]

Originally Posted by jrivera

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. Oh well!

Mic

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 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




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[klott]

Looks too small to be a Hi efficiency unit.

[klott]

One way to tell on the inside unit is if it has a plastic vent pipe, it is a 90% efficient unit, right Charley?

[klott]

Originally Posted by jrivera

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. Any manfactured after January 23rd 2006 must have a minimum rating of 13 SEER, however, units manufactured before that time may still be used until the stock is depleted.

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. Oh well!

Mic

Rheem units that start with RAND in the model number are 13 SEER or above, according to Rheem. FWIW

[phinsperger]

Originally Posted by cbottger

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 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


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Charley, I think your definition of efficiency is basically flawed. From what I read in your post, a 6 ton, 8 SEER unit in a 1000 sqft home would would clasifiy as hi-eff. I don't think so. Efficiency are measured under certian conditions. Conditions that can be reproduced and verified when needed. Specific applications will alter the conditions which affects the actual output perfomance which I think is what you are trying to say.

[Michael Larson]

Charlley,

I tried to give everyone a clue when I wrote Size and small.
I didn't want to give it away right off.

[Charley L. Bottger]

Originally Posted by phinsperger

Charley, I think your definition of efficiency is basically flawed. From what I read in your post, a 6 ton, 8 SEER unit in a 1000 sqft home would would clasifiy as hi-eff. I don't think so. Efficiency are measured under certian conditions. Conditions that can be reproduced and verified when needed. Specific applications will alter the conditions which affects the actual output perfomance which I think is what you are trying to say.

Paul I think you missed my point I have never seen a 6 ton unit but say for the point of discussion there is; my point is the condenser on a 6 ton 8 seer unit would be smaller than the condenser on a 6 ton 13 seer. Just like the 2 ton in the pic no way for it to be a 13 seer the condenser is to small. Not trying to make HVAC techs out of HI's just trying to point out some physical features that are very visible even to a HI. When I first saw the small 2 ton unit I had not even looked at the furnace or the area that it served but I had stored in my memory bank that is was a low efficiency unit and would probably have a hard time cooling its designated area with high outside ambients. I try to document that type of information in my report and when I get one of those phone calls that starts out with YOU inspected my home and my A/C unit runs all of the time never shuts off I can look at my report and explain why.

Back before the days of published seer ratings carrier made what they called a high efficiency unit and the tag on the top stated high efficiency the unit was in the shape of a very large soup can, very large condenser but they also made a low efficiency unit with the same size compressor but the unit was in the shape of a Ham can very small condenser with no advertised rating on the unit. Both units would have the same compressor installed no difference.

[Charley L. Bottger]

Originally Posted by mlarson

Charlley,

I tried to give everyone a clue when I wrote Size and small.
I didn't want to give it away right off.

I knew what you were doing I was just jacking with you.

[Charley L. Bottger]

Originally Posted by klott

One way to tell on the inside unit is if it has a plastic vent pipe, it is a 90% efficient unit, right Charley?

Yes that is a good indication about the furnace but has nothing to do with the outside unit because you can have a low seer unit outside installed on a high efficiency furnace would not make any sense to install that way but you never know what makes people think.

[Michael Larson]

Originally Posted by cbottger

I knew what you were doing I was just jacking with you.

Good, I was afraid I was being too subtle.