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
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.
I was employed for six years, doing just that.
There is a heck of a lot to know, and a lot of
specialty parts to have on hand. Not saying it's
impossible, but it took me several installs to
get the hang of it.
And about two years from now, expect a thread about
"Repairing Central A/C Yourself?"
"I've been getting very high quotes for repairing
my central AC. I've checked the price of freon,
but the companies want...... "
I wonder if the OP checks the price of burgers
before going to Burger King?
I did mine about 12-13 years ago , replaced the furnace and added AC .
Second summer it didn't cool too well , because I had a leak in a fitting on
the LP side tubing . Fixed that and recharged and the only problem since was
a blown S/R cap in the condenser unit - and my son replaced the supply
breaker recently because it went bad .
I did have prior experience with refr work <Dad did AC/R> , metal work ,
and electrical ...
On Tuesday, May 6, 2014 6:28:55 PM UTC-4, Terry Coombs wrote:
I replaced my gas furnace and AC 3 years ago. I did a lot of research
first and I didn't run into anything really unexpected. Like many
things, it's more work than you would think. It was about $4000 for
the eqpt for a 5 ton AC, 120K BTU furnace.
Some answers and comments:
To do the brazing of the copper lines, you need to flow nitrogen through
the system, otherwise the high temps will cause oxidation and you'll
have crud inside the new system.There are alleged "pros" out there that will skip that step, but if you want to have a system that fails prematurely,
the choice is yours. In retrospect, if I had to do it all over again,
instead of brazing, I'd use Staybrite 8, which is solder with silver
added. If you do some research, you'll see pros bitching back and forth
about whether it's OK or not. There are plenty that have used it for
decades. Also, if you google, you'll find a Harris Products video that
shows what happens when you braze fittings versus use the Siverbrite 8.
While people believe brazing is stronger, there is more to it than that.
The joint itself is stronger with brazing, but the high heat affects the
soft copper tubing. Harris shows videos of where they pressure test both
methods to the failure point. The brazed tubing fails first, bursting
near the joint. The Staybrite stays intact to higher pressures. If you
use Staybrite, you can probably skip the nitrogen because the temps
required for soldering are much lower than brazing, so it's unlikely
that crud is going to form.
The system comes pre-charged, with enough refrigerant for a given length
of lines. If your lines are about the right length, it should not need
additional charge. But it does need to be evacuated with a vacuum pump
prior to opening the valves. Doing that right is critical. So, it's more practical to get someone to
do that portion of the job. I found a guy on Craigslist, and of course
anytime you're dealing that way there is some risk. I had longer lines,
so he had to top it off too.
You're almost certainly not going to wind up with a warranty that will
be honored by the manufacturer. But I'm 3 years in and it's all working
And I'd look into state, utility, etc rebates. I got the fed tax credit,
but no state/utility rebates. The state/utility rebates required information
and processes that you couldn't complete yourself, at least not easily.
For example, they required a complete manual J calculation, so I just
said to hell with it. I still saved several thousand dollars. But it's
worth making the true price comparison, including any rebates that you could
get if you do it via a contractor.
Also, you probably need to pull permits, depending on where you live.
I had to pull three here in NJ.
I'd install it, call an HVAC company and say it's not working. They'll come
and check it out and charge it. If they ask how it got there, shrug your
shoulders and say "I don't know, it was like that - I inherited this house
from my insane uncle who lived in an electric blanket fort and didn't need a
To the OP Steve: Have you tried discussing your worksheet with an HVAC
contractor? Sometimes you can work a deal if they know you know what their
equipment costs are, and whatever you get stuff for, they can likely get it
for 10 to 25% less. Sometimes they'll get hot enough to need an ice bath
but it's always worth a try. It helps to get beyond one of the commissioned
salesmen and to a manager, which could be easy or impossible.
It also helps to communicate that if they're unwilling to make a deal,
you've got the yellow pages in front of you and lots of time to call other
people. You might have to wait until they have some slow time, too, to get
any kind of a break. With the first heat wave of the year approaching here,
it's probably not going to be an ideal time for wheeling and dealing.
I had a boss that was a pro at this sort of stuff. He was an ex-tank
commander from the first Iraqi war and knew his vehicles inside and out. He
could make car dealers cry because he knew not only what their cost was, but
how much it helped them to add even a near zero profit sale to their books.
That's because they're always involved in manufacturer/dealership
"contests/programs" to see which dealer moves the most cars per
quarter/year. IOW, if they move enough cars, they get "spiffs" that can
easily make up for not making much money on the occasional sale to a
hardball negotiator. They know if they don't sell you that car, you'll get
it from some other dealer and their yearly sales figures will go up.
He had some other good rules. When the salesmen says "I've got to run this
by my manager" he would insist "I guess it's time for me to talk to the
manager myself - just to make sure we're clear on what I want."
The big secret was to always be ready to walk away, which he did, often.
But he always left his business card and they always called back with a
better deal. "I just talked to my manager and he said he was willing to
GIVE you the Truecoat (or whatever) for cost." Then he would say "But I
don't want it at ALL because it can actually cause premature rusting!" and
hang up. That could go another few rounds because IIRC, the true cost of
applying that crap is appalling low compared to what they try to charge.
As for what Pete said, I agree. Sheet metal work is a bitch. It helps to
have a truck full of various elbows, reducers, etc. when fitting a new
furnace. FWIW, I've never been able to do duct work without ending up with
a serious scar to memorialize the job. The big problem with a self-HVAC
install is that you're going to need a helper to position stuff or run to
the Home Depot for whatever you need to connect something that's not quite
This is when you're especially glad if there's a Home Depot or Lowe's or
wholesaler just a few miles away. Case in point. I thought I had
everything I needed to install a central vac by myself. Hah. Three
separate trips to get a new hole saw, a spade bit extension and some new
fittings for the ones I swear I press-fit checked but that were not "on the
beam" after I glued them.
On Wednesday, May 7, 2014 8:40:52 AM UTC-4, bob haller wrote:
The direct vent thing brings up another issue. OP didn't say what
exactly he has, but if it's a furnace on a chimney shared with a gas
water heater, when he goes to direct vent, if he's in a cold climate,
with the chimney exposed and he leaves the gas water heater, he should
put in a liner. I think he's in CA though, so may not be an issue.
I always wonder about those comments about a oversize flue. around here they are seperate flues.
Now take the follwing breakdown situation!
The furnace and water heater share the flue...
the temperature isnt very cold.
a hot water line breaks for any reason.....
so the water heater is coming on but the furnace has nearly no reason to come or breaks somehow so the furnace burner never comes on.
whats the difference between a direct vent furnace install, so it never vents exhaust gas in the chimney, but the water heater still does?
On Saturday, May 10, 2014 3:11:39 PM UTC-4, bob haller wrote:
The difference at issue here is if it's in a climate
where it's cold during winter and at least part of the
chimney is exposed, ie not withing the heated part of
the building. Then with a cold, over-sized chimney,
the combustion gases from the orphaned water heater will
condense inside the chimney. That produces acidic condensate,
which over many years can eat away at the mortar in the chimney,
causing failure. A liner eliminates the problem. With the old
furnace venting into the chimney, it provided heat to keep the
chimney warm enough so that condensation was not possible.
Aside from that, chimneys are supposed to be sized to the
appliances, so that it will draft properly. You can probably
get away with that being oversized in most cases, eg the chimney
still works for just the water heater in summer, when the furnace
wasn't running, but it's better if it is properly sized.
On Tuesday, May 6, 2014 4:22:16 PM UTC-4, sms wrote:
At one point I had two houses and a condo. Total of 4 split heat pumps, 2
split ac, and two gas furnaces. So I started doing my own. I figured the
cost of gauges, an economy vacuum pump, and a few special tools was not tha
t bad. I use silver solder instead of brazing so I don't need a nitrogen t
ank. Never had a problem with silver solder. I got rid of one of the hous
es so I'm not trying to keep up with so much but I still fix what I have an
d what is left is all split heat pumps. If you'r planning on doing your ow
n hvac work long term the equipment cost is not to bad. I did have to get
the basic epa certificate to be able to buy refrigerant. And buying whole
systems is a pain because most outlets will only sell to pros. You go out
in the country and you find more places that are used to people doing their
own work so it gets easier to buy a complete system. Plus the internet.
Buying parts is no problem anywhere.
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