RicodJour wrote:

cowboy wrote:

c actually shade matters a lot in your utility bill, that is why I said
c it would cost less.

As I said before, you are mistaken. the air over the condenser coil keeps
it
cool even with the sun on it. sunlight has a very minute influence on the
head pressure. please get some training somewhere before you try to answer
these questions. you really do need it.


you are really embarrassing yourself in front of everyone, this point is not
even debatable!

you don't get to defy basic science, no matter how clueless you are!

if you really believe this (because you have never had a class in basic
thermodynamics, and are basically just a stupid redneck with a GED) you can
easily prove it to yourself by doing a simple experiment that even YOU can
understand!

hook a clamp on ammeter around the unit's lead-in, measure current draw
after running unit in the sun for an hour in the hot part of the day, then
shade condenser and measure in another hour (make sure that the ambient temp
outside is the same in both cases)

you will see a significant difference in energy consumption!


I posted this on the alt.hvac board - didn't find it's own way here.

Stormin Mormon wrote:

I'd have to dig around for a link. But someone posted a couple months back a
web site where they did study this. two identical houses, they put the
condensing unit in the shade for one, the sun for the other. They found less
than 5% energy usage difference. Doesn't make sense to me. I mean, I'm a lot
cooler in the shade, seems a condensing unit should be, too.


Is this the study? http://www.fsec.ucf.edu/bldg/pubs/pf302/
They found less than expected energy savings - minimal in fact. They
figured 3% savings or less would be the maximum effect, and their study
averaged essentially zero.
R

That study doesn't seem to agree with your position. I'm not arguing
the thermodynamic principals, just pointing out that an unbiased,
highly regarded authority in the energy field did a real life study
over a couple of years and found negligible difference between shaded
and unshaded condensors. How do you explain that?

Paul came up with approx a 2% gain. OTOH, that is considering 100%
absorption and a perpetual maximum exposure.
I converted this to a savings of a dollar or two per month during the
hot summer, but didn't subtract for the partial exposure and partial
absorption. With these accounted for it works out to less than one
dollar per month savings during the hottest months. Also the heat
exhausted from the condenser is the sum of the extracted indoor heat
plus the energy input to the compressor, thus Paul's hypothetical figure
of 36000 btu/hr would have to be adjusted to account for the EER,
further reducing the percent savings.

hvacrmedic



R