J Jensen wrote:
1. Keeping the a/c cooling the house all day uses less electricity
than turning it off and then back on in the evening or when you
return from a vacation.
False.
http://www.ontario-sea.org/34kyoto/ac.html

2. Running the a/c a few degrees colder at night cools the big cement
slab that the house is built on, and thus saves electricity during
the day (the a/c is set back to normal living temperature during
the day).
False.
http://www.ontario-sea.org/34kyoto/ac.html

2b. If the temperature inside the house reaches 78 F at 10 AM on both
days with the a/c set colder the previous night, and also when it
was just set normally the previous night, then that proves
setting it colder made no difference.
False.
Many, many variables in this equation.

3. The a/c uses less current at night ( you measure it with an
ammeter as it is running ).
Depends. Compressor current consumption can vary with the load.

4. The a/c uses less current if you spray the outside unit with the
garden hose and then measure it with the ammeter.
See above.

5. Shading the outside unit (compressor and condenser) does not reduce
electricity costs [Assume shade does not block air flow].
It depends.
http://homeenergy.org/archive/hem.di...95/951102.html

6. If you have high ceilings and ceiling fans, it is more energy
efficient to leave the fans running at low speed all the time to
pull down hot air and get it to circulate through the a/c system.
Fans don't cool rooms, they cool people (due to the evaporative cooling
effect on skin). To save energy, turn fans off when you leave the room.

7. It isn't worthwhile to check on the amount of Freon (or whatever)
that is in the system -- all that matters is measuring the
temperature of the cold air coming out (say 62 F) and the outside
temperature or maybe the attic temperature.
False.
There are many factors that influene the measured temperatures besides
the refrigerant charge..