Question:
Would anyone offer any detailed info or suggestions regarding the
installation of a central air conditioner for a DIY'er?
Answer:
Aside from the refrigerant licensing issue's and refrigerant charging
issues, my understanding is that all the instructions you need are provided
with the unit. This instructions should cover all the mysterious parts to
the installation. The others mysteries you imply are the endless a/c
installation configurations that professionals have to deal with. But you
will dealing with only 1 specific installation.
I assume you are able to provide sound electrical circuits as needed. If
you can do the duct work, electrical work, refrigerant work and have a place
to buy it, then have a go at it. My personal obstacle has always been
fabricating the metal duct work, but I understand that you can buy pre-made
plenums and ducts.
Watch out for the little things like not using galvanized hangers for the
copper line set, which would cause accelerated corrosion. Many units are
built with heating devices inside the outdoor condensing unit (too lengthy
to explain) and the unit must be energized 24 hours before turning on the
compressor to avoid damage to the compressor. Mount the thermostat on an
interior house wall away from wall switches or anything that emits heat or
draft. Install cooling vents near windows and the return vents across the
room from the cooling vent. Since your using ceiling vents, I would guess
that you want floor level return ducts for optimum cross draft, but I would
find out for sure before cutting holes. The unit must be on a dedicated
electrical circuit and you definitely don't want to take any short cuts on
wiring. For example, use an outdoor 'disconnect' box, double pole breaker,
proper grounding, etc.
My house utilizes some return air via the hollow wall studs and the
"flexible insulated ducts" are very popular. Your secret tool is your
'friend in the business'. How far away from the air handler is the outside
unit? It would be ideal to keep it within 25' to avoid custom length lines
and to avoid adding 'extra' refrigerant to a pre-charged system. Be sure
you get the right length line set. 15' and 25' are common. If you have to
add refrigerant for long line sets, that gets tricky real fast and unless
you already know how to do it, I doubt you will be able to perform that
yourself without some skill and expensive tools and of course a license is
required to 'open' a system. You need a drain for the condensate pan in the
air handler.
