Hello,

I have an airconditioned room that seems to require more
airconditioning than the other rooms from the difference of the amount
of time I've noticed the compressor being engaged between those rooms.

They are all with walls being hit by the sun from noon till sunset,
with the exception of the hot room which has a steel door facing the
run.

The walls are pretty reasonable in tempreture when touched, the steel
door which is dark brown is very hot.  You can feel the heat on your
face if you stand close to it.

I was thinking of shading the door as it seems like the reason behind
the high temprature exchange between the outside and inside
environments for that particular room.

I was also wondering what would happen if I only covered its outside
area with aluminum foil?  Would that suffice?

The two amounts of effort are not comparable and it's not visible to
humans from the outside so there's no esthetic loss by covering it up
in an ugly manner. :-)

The question is basically, how much return on investment between the
two methods I'm looking at in comparison to the effort and cost and
benefit out of the two means?

/lizardnation

Most economical solution is to simply paint the outside
side of the steel door white. 
 Use primer first, possibly two coats.

As the looks are irrelevant, the difference is in ease of application
and durability. The cooling effect is about the same for good paint
and foil:

>For the sake of clarity let me point out I was comparing mirror GLASS with
>white paint.  Silvered glass reflects only 88 - 93 of incident light
>according to my trusty, if outdated, copy of the CRC Handbook.
>  Certain white paints reflect 85 - 98 percent of incident light.  

http://fins.actwin.com/aquatic-plants/month.9702/msg00453.html

data on different types of paints:

http://www.rima.net/handbook/page3.htm

Large amount of data comparing shading and reflectant paint 
and films;
.. with Titanium Dioxide .85 Ordinary White Paint .77-.51 ..
. VS a sheet of aluminum foil with a ..
www.state.sc.us/energy/Energy%20Briefs/ EB%20Cooling%20Home%20Naturally.pdf



SEARCH TERMS
 Reflectance, paint, foil

          Good Luck 
hedgie

Completely put the issue to rest for me. :-)

/Lizardnation