On Feb 1, 11:20 pm, Ermalina wrote:
"" wrote:

We live in Southern Arizona.
The A/C unit is on the south side of the house.
and gets direct sun most of the day.
In the summer time, you could fry eggs on the A/C housing.

Is there any advantage to erecting some sort of shade
over the A/C unit ?

Enough to where the ( energy ) savings would be significant ?

( planning my summer projects.... )

rj

I was surprised to find this:

http://www.homeenergy.org/archive/he...95/950904.html

Excerpt:

"Air Conditioner Shading Shows Minimal Savings

"A study by the Florida Solar Energy Center (FSEC) on the effects of
shading outdoor air conditioner condensers indicates that energy savings
benefits are modest at best--less than 5%. Although the study involved
just three sample cases, and researchers describe the experiments as
somewhat inconclusive, the results suggest that if shading is not done
properly, the risk of interrupting air flow to the condenser could more
than offset any benefits."

and a follow-up by the researchers:

http://homeenergy.org/archive/hem.di...95/951102.html

"Our report, "Measured Impacts of Air Conditioning Condenser Shading"
(FSEC-CR-827-95), does not show that shading A/C condensers cannot save
energy (see "Air Conditioner Shading Shows Minimal Savings," Sept/Oct
'95, p. 7). It does indicate that the potential savings are small. The
report shows that if done properly, as at Site 1, an improvement in A/C
efficiency of about 1% can be realized. On the other hand, the data show
that when shading is done improperly, A/C efficiency can be lowered.
Proper and improper shading strategies appear to be delineated by the
proximity of the landscape shading to the condensing unit and its air
flow pattern. A proper attempt at A/C shading would use landscape that
is sited so that the unit is shaded in the late afternoon hours, but air
flow is not impeded--particularly the hot exhaust air plume. This
usually means using larger specimens (or waiting for smaller ones to
grow), so that the shade trees are at least 6 ft away from the unit. We
do indicate that such shading is not cost-effective when done solely for
the purpose of shading an air conditioner. However, often landscaping is
placed around homes for other purposes (beautification), and allocating
one or two medium shade trees to this duty might be considered a no-cost
option."


I saw that report too. I found it interesting that when the first
study showed some savings, they almost dismissed it because it was
less than 5%. I don't know about you, but I would think saving say
4% on an cooling bill in say AZ or FL is not insignificant. If you
spend $1000 a year on cooling, that's $40 every year. And if you can
work some attractive landscaping into it that brings other benefits as
well, it seems well worth it to me.

If it really is only 1%, then I agree it's not worth it. And the
bigger issue is that if in the process you block airflow at all, then
it can have a neg impact.

For another opinion, here's what DOE says:

http://www1.eere.energy.gov/consumer...ditioners.html
Plant trees or shrubs to shade air conditioning units but not to block
the airflow. Place your room air conditioner on the north side of the
house. A unit operating in the shade uses as much as 10% less
electricity than the same one operating in the sun.


But, unfortunately, they don't cite what this is based on.