sms wrote:

I've been getting quotes for central A/C and they all seem very high.

The basic components are available to me at the following prices:

Air Conditioning Condensing Unit Horizontal Discharge, 13 SEER,
Single-Phase, 2 Ton, R410A $1300

Evaporator: $230

Replacement furnace: $550

So the big items are about $2300 including tax. The quotes I've been
getting are around $7000.

I don't really need a new furnace, but the existing one is about 32
years old and it's so tall that to install the A/C would require a lot
of duct work to fit in the evaporator, while with a new, shorter
furnace, there is no duct work needed.

The 230V power and all the plumbing are already in place. The electrical
panel needs a circuit breaker connected to the 230V wiring that's coiled
up behind it. I need to change the furnace blower motor from plug-in to
hard-wired with a switch, which is easy to do.

Has anyone here done their own A/C install?

In order to do your own install, you will normally need to find an HVAC
tech who will charge and check the system for you. In some areas this
may be difficult to find, while in other areas it may be easy to find a
moonlighting HVAC tech to help you out. The charging and checking are
the parts HVAC techs like, screwing around getting ductwork to fit
(especially retrofit) and the like are the less popular tasks.

I did my own HVAC install and had an HVAC tech friend charge and check
the system. Since I did the install to my standards and on my schedule
it was done extremely neatly (my friend was impressed). The install was
5 or 6 years ago and everything is still performing nicely. I've also
helped my friend out on some of his moonlighting work since I happen to
be pretty good with ductboard.

Doing it all yourself is possible but not really practical since you'd
need to get your EPA refrigerant license (I did) and also buy tools like
a gauge set that you wouldn't likely use again. Much easier to find a
tech to do the charging for you.