Alternative Power sources - A/C efficiency

Author

A/C efficiency

Robert Morein

2005-10-12, 8:21 pm

I've been looking for replacement central air. The most advanced system I
have been able to discover is Trane's 19.3 SEER unit, which uses two
asymmetrically sized compressors, providing two "on" states. The unit also
has a DC drive proportional control evaporator fan.
However, I am surprised that Trane still uses AC induction motors to power
the compressors. Do any manufacturers offer more efficient compressor
drives, such as permanent magnet motors driven by inverters?

Solar Flare

2005-10-12, 10:21 pm

10 years ago when I installed my A/C unit the figures out there were SEER 10 and
very rarely SEER 13. The saving in consumption at $10 per month in energy would
have never paid for itself in my lifetime. This would also indicate that the
energy to produce this product to my wall would also never break even on the
savings. Some green effort.

I have to assume this is still the case with these new higher SEER ratings.

"Robert Morein" <nowhere@nowhere.com> wrote in message
news:1_SdnS7-0IJUCdDeRVn-vg@giganews.com...
> I've been looking for replacement central air. The most advanced system I
> have been able to discover is Trane's 19.3 SEER unit, which uses two
> asymmetrically sized compressors, providing two "on" states. The unit also
> has a DC drive proportional control evaporator fan.
> However, I am surprised that Trane still uses AC induction motors to power
> the compressors. Do any manufacturers offer more efficient compressor
> drives, such as permanent magnet motors driven by inverters?
>
>

RF Dude

2005-10-12, 11:21 pm

Sale of 10 SEER units will be banned as of January 2006. New minimum is 13
SEER. This is represents an operating energy savings of 30%. The higher
efficiency units cost $500 to $1000 more, and have larger condenser coils
(the unit stands higher). If you live in a hot climate, the higher
efficiency makes economic sense. Long term, the cost of the 13 SEER units
should come down. But if you live further north, the extra cost for 13 SEER
is likely a waste of money. Where I live (around the 42nd parallel), we
operate A/C about 3 to 4 weeks per year. The rest of the time open windows
in the evening suffice. I purchased a 10 SEER unit on sale this year.

mike wilcox

2005-10-13, 12:21 am

Solar Flare wrote:
> 10 years ago when I installed my A/C unit the figures out there were SEER 10 and
> very rarely SEER 13. The saving in consumption at $10 per month in energy would
> have never paid for itself in my lifetime. This would also indicate that the
> energy to produce this product to my wall would also never break even on the
> savings. Some green effort.
>
> I have to assume this is still the case with these new higher SEER ratings.
>
>
> "Robert Morein" <nowhere@nowhere.com> wrote in message
> news:1_SdnS7-0IJUCdDeRVn-vg@giganews.com...
>
>
>
>

I would consider going from a SEER 10 to 19.3 in ten years quite a
saving. A seer 19.5 uses almost half the electricity than a Seer 10
and likely costs less to produce than the old 10 seer unit of 10 years ago.

Solar Flare

2005-10-13, 12:21 am

Exactly. I live just above 43 degrees and the a/c runs sometimes a full two
months. The possible $60 for the year would never pay for the $1000 increased
cost of the unit (at the time)

The installers said they never put them in because nobody wanted them and they
were very rare to obtain.

This was 10 year back now.

"RF Dude" <post@thisnewsgroup.com> wrote in message
news:trj3f.5504$S43.725041@news20.bellglobal.com...
> Sale of 10 SEER units will be banned as of January 2006. New minimum is 13
> SEER. This is represents an operating energy savings of 30%. The higher
> efficiency units cost $500 to $1000 more, and have larger condenser coils
> (the unit stands higher). If you live in a hot climate, the higher
> efficiency makes economic sense. Long term, the cost of the 13 SEER units
> should come down. But if you live further north, the extra cost for 13 SEER
> is likely a waste of money. Where I live (around the 42nd parallel), we
> operate A/C about 3 to 4 weeks per year. The rest of the time open windows
> in the evening suffice. I purchased a 10 SEER unit on sale this year.
>
>

Solar Flare

2005-10-13, 12:21 am

Somehow I doubt that. More research needed on that one for my new house I will
build next.

"mike wilcox" <appraisers@sympatico.ca> wrote in message
news:Jxj3f.4904$vD4.343711@news20.bellglobal.com...
> saving. A seer 19.5 uses almost half the electricity than a Seer 10
> and likely costs less to produce than the old 10 seer unit of 10 years ago.

Bill Kaszeta / Photovoltaic Resources

2005-10-13, 1:21 am

On Wed, 12 Oct 2005 18:57:13 -0400, "Robert Morein" <nowhere@nowhere.com> wrote:

>I've been looking for replacement central air. The most advanced system I
>have been able to discover is Trane's 19.3 SEER unit, which uses two
>asymmetrically sized compressors, providing two "on" states. The unit also
>has a DC drive proportional control evaporator fan.
>However, I am surprised that Trane still uses AC induction motors to power
>the compressors. Do any manufacturers offer more efficient compressor
>drives, such as permanent magnet motors driven by inverters?
>
>
Ten years ago Trane mave a variable speed unit with a permanent magnet rotor,
but they discontinued it when they changed to scroll type compressors. Seems that
it was costly and the scroll compressors have lower efficiency at lower speeds
compared to piston compressors.
Bill Kaszeta
Photovoltaic Resources Int'l
Tempe Arizona USA
bill@pvri-removethis.biz

Roy Starrin

2005-10-13, 9:21 am

On Wed, 12 Oct 2005 22:15:56 -0400, "RF Dude" <post@thisnewsgroup.com>
wrote:

>Sale of 10 SEER units will be banned as of January 2006.
Not quite so. Dealers,etc., can sell/install 10 SEER as long as they
have them. There will not be any new ones made.

SQLit

2005-10-13, 3:21 pm

"Robert Morein" <nowhere@nowhere.com> wrote in message
news:1_SdnS7-0IJUCdDeRVn-vg@giganews.com...
> I've been looking for replacement central air. The most advanced system I
> have been able to discover is Trane's 19.3 SEER unit, which uses two
> asymmetrically sized compressors, providing two "on" states. The unit also
> has a DC drive proportional control evaporator fan.
> However, I am surprised that Trane still uses AC induction motors to power
> the compressors. Do any manufacturers offer more efficient compressor
> drives, such as permanent magnet motors driven by inverters?

Your idea might pick up a few efficiency points but the costs would
definitely out weight the saving.

Who knows there might be one in testing right now.

Pete C

2005-10-13, 3:21 pm

Dave Hinz

2005-10-13, 3:21 pm

On Thu, 13 Oct 2005 19:08:19 +0100, Pete C <petecnews@gmail.com> wrote:
> Hi,
> What's the relationship between SEER and COP, anyone know?

Not to be a smartass, but google gives great links on a search of:
seer cop table

Solar Flare

2005-10-13, 5:21 pm

Where?

"Roy Starrin" <starrin@verizon.net> wrote in message
news:bojsk1dokeh7totua9mfi08fk11rncd4g5@4ax.com...
> On Wed, 12 Oct 2005 22:15:56 -0400, "RF Dude" <post@thisnewsgroup.com>
> wrote:
>
> Not quite so. Dealers,etc., can sell/install 10 SEER as long as they
> have them. There will not be any new ones made.

Pete C

2005-10-14, 2:21 pm

Hi,

Thanks for the replies, looks like COP = EER/3.413 so 13 EER = 3.8
COP.

This would be quite easy for a split air conditioner, in the UK ones
with a COP of ~4.5 aren't too expensive.

Would A/C in one or two rooms be acceptable for occasional use? For
longer use several units or a multi-split would be better.

cheers,
Pete.

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