The air coming out should be "about" 15F cooler than the air
going to the unit.

Shorter line set from the furnace to outdoor unit is good --
less pressure loss from the tubing.

Dirt and dust has a major effect, and all of the effect is
bad. The outdoor units very often get a lot of dust, and
that has bad effects.

Women often cannot be reasoned with.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"The Henchman" wrote in message
...

20 or 25 year old central air unit here.

I took a fairly accurate insta-read laser thermometer and
discovered that
the temp coming out of the ducts is about 60 or 62 F in
most rooms (I'm in
Canada but I still use F) House is set to to be cooled to
76 when we are
home and 73 at bedtime. When we are away house is set for
83 F. Humidity
right now is about 55% inside.


So If the air about 4 feet up is 76 F and the air coming out
of the vent
during cooling is 60 or 62, is this still reasonable?

Looks like the refrigerant run from the a-coil/furnace to
the compressor
unit outside is 18 or 20' including bends. Insulated. This
a nice short
run? I notice in other homes about a 40 to 50' run. Does
the length of run
make any difference?

What effect does dust or dirt have on the blower during a/c
season?

Any use running the blower all day on a hot day to keep the
air circulating
or is that a waste of energy. My wife insists no ceiling
fans whatsoever.
I've argued three times and she still insists no ceiling
fans.