I live in San Diego. House is 1600 sqft. My furnace is a 23 year old
Day&Nite 80,000 BTU unit. It uses a 3 ton split system air conditioner, also
23 years old.

The A/c sees very little use and is working fine. The furnace is getting
cranky and I would like to replace it.

Is it necessary or advisable to replace the a/c compressor and coil when I
replace the furnace?

Is there any cogent need to replace even the coil? After all, there is no
wear/tear on the coil. Can I just replace the pan under the coil when I
replace the furnace?

I realize that a new A/c compressor and coil would be more efficient but we
only use the a/c during an occasional hot spell, maybe 10 days a year.
--

Walter
The Happy Iconoclast www.rationality.net

Walter E. wrote:
I live in San Diego. House is 1600 sqft. My furnace is a 23 year old
Day&Nite 80,000 BTU unit. It uses a 3 ton split system air
conditioner, also 23 years old.

The A/c sees very little use and is working fine. The furnace is
getting cranky and I would like to replace it.

Is it necessary or advisable to replace the a/c compressor and coil
when I replace the furnace?

Is there any cogent need to replace even the coil? After all, there
is no wear/tear on the coil. Can I just replace the pan under the
coil when I replace the furnace?

I realize that a new A/c compressor and coil would be more efficient
but we only use the a/c during an occasional hot spell, maybe 10 days
a year.

23 years old! Yea I would replace it. Considering where you are it may
take a while to get your money back, but you are going to save a good
percentage on the cost of running it. I suspect if you factor in the
potential for breakdowns, and the expense and possible lack of available
parts, you may actually be ahead a lot sooner.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

"Walter E." wrote in message
news:1111699211.ceb1f890ed928c63dd22626c4727539b@t eranews...
I live in San Diego. House is 1600 sqft. My furnace is a 23 year old
Day&Nite 80,000 BTU unit. It uses a 3 ton split system air conditioner, also
23 years old.

The A/c sees very little use and is working fine. The furnace is getting
cranky and I would like to replace it.

Is it necessary or advisable to replace the a/c compressor and coil when I
replace the furnace?

Is there any cogent need to replace even the coil? After all, there is no
wear/tear on the coil. Can I just replace the pan under the coil when I
replace the furnace?

I realize that a new A/c compressor and coil would be more efficient but we
only use the a/c during an occasional hot spell, maybe 10 days a year.
--

Walter
The Happy Iconoclast www.rationality.net


This is Turtle

By what you say --- I would change the furnace out and let it go. You only have
one thing to change the A/C out for and that is failure and lost of A/C during
the hot times. now with only 10 days or so as your failure time is cut way down.

TURTLE

"Walter E." wrote:
I live in San Diego. House is 1600 sqft. My furnace is a 23 year old
Day&Nite 80,000 BTU unit. It uses a 3 ton split system air conditioner, also
23 years old.

The A/c sees very little use and is working fine. The furnace is getting
cranky and I would like to replace it.

Is it necessary or advisable to replace the a/c compressor and coil when I
replace the furnace?

Is there any cogent need to replace even the coil? After all, there is no
wear/tear on the coil. Can I just replace the pan under the coil when I
replace the furnace?

I realize that a new A/c compressor and coil would be more efficient but we
only use the a/c during an occasional hot spell, maybe 10 days a year.

With 10 cooling days a years, you'll never see a payback replacing it early.
If it ain't broke...

I agree. If you used your AC a lot, the payback would be worth it.
But with 10 days use a year the payback would be forever. I believe in
selling high efficiency, but not if it doesn't save the customer money
or improve their comfort. Wait till the AC Croaks, then replace the
outdoor unit and indoor coil together for reliability and longevity.
They are sold as matched sets and will work better if replaced
together. The only other issue with a 23 year old indoor coil is they
typically remove dirt from the air that the filter misses. This is
because the coil makes a good filter when wet. The dirt gets caught
inside the coil and affects air flow by blocking the spaces between the
fins. If they check the coil when they replace the furnace, they will
be able to tell you if it needs replacing. But with 10 days a year
use, it will probably be OK.

Stretch

"Joseph Meehan" wrote in message
...
Walter E. wrote:
I live in San Diego. House is 1600 sqft. My furnace is a 23 year old
Day&Nite 80,000 BTU unit. It uses a 3 ton split system air
conditioner, also 23 years old.

The A/c sees very little use and is working fine. The furnace is
getting cranky and I would like to replace it.

Is it necessary or advisable to replace the a/c compressor and coil
when I replace the furnace?

Is there any cogent need to replace even the coil? After all, there
is no wear/tear on the coil. Can I just replace the pan under the
coil when I replace the furnace?

I realize that a new A/c compressor and coil would be more efficient
but we only use the a/c during an occasional hot spell, maybe 10 days
a year.

23 years old! Yea I would replace it. Considering where you are it
may
take a while to get your money back, but you are going to save a good
percentage on the cost of running it. I suspect if you factor in the
potential for breakdowns, and the expense and possible lack of available
parts, you may actually be ahead a lot sooner.

In stuff like this, labor is a big part of the installed cost. They are
gonna have the whole thing apart and the a/c discharged anyway. Especially
considering how small modern furnaces are- the HVAC guy would probably have
to kludge up something complicated to make the old A/C properly fit onto the
new furnace. Not to mention how to integrate it into the control system.
Definitely, replace it all. Even if the payback in energy costs will be
decades, most of the money should be recovered when OP or their heirs sell
the house. A young furnace/AC is a big sales point.

aem sends...

If it were me, I'd replace the whole thing. At the very least, I'd get
quotes on what the cost is to replace the whole thing now, versus what
it will cost if you want it done seperately. I think you'll find it
will cost considerably more to do it piece meal and at 23 yrs, you're
on borrowed time. Also make sure to look into any rebates from the
elec company that are frequently available.

I'm sure by now you've read all the comments from everyone. I want to throw
in my two cents worth....

As of January 2006, 13 SEER efficiency will be the law of the land for AC's.
IF (caps intended) you don't replace it before then and it goes out after
January 1, 2006, you'll have to pay considerably more for the 13 SEER
equipment.

Your call.


"Walter E." wrote in message
news:1111699211.ceb1f890ed928c63dd22626c4727539b@t eranews...
I live in San Diego. House is 1600 sqft. My furnace is a 23 year old
Day&Nite 80,000 BTU unit. It uses a 3 ton split system air conditioner,
also
23 years old.

The A/c sees very little use and is working fine. The furnace is getting
cranky and I would like to replace it.

Is it necessary or advisable to replace the a/c compressor and coil when I
replace the furnace?

Is there any cogent need to replace even the coil? After all, there is no
wear/tear on the coil. Can I just replace the pan under the coil when I
replace the furnace?

I realize that a new A/c compressor and coil would be more efficient but
we
only use the a/c during an occasional hot spell, maybe 10 days a year.
--

Walter
The Happy Iconoclast www.rationality.net

If I lived in San Diego and had your house I'd consider tossing the A/C
and furnace and getting heat pump.

HeatMan wrote:
I'm sure by now you've read all the comments from everyone. I want to throw
in my two cents worth....

As of January 2006, 13 SEER efficiency will be the law of the land for AC's.
IF (caps intended) you don't replace it before then and it goes out after
January 1, 2006, you'll have to pay considerably more for the 13 SEER
equipment.

Your call.

Just a clarification: As of Jan. 2006 only 13 SEER or above can be
MANUFACTURED, but anything manufactured before this date can still be
sold. So, lower SEER equipment will still be available for awhile.

I checked with three of my suppliers, Trane, Rheem, and Carrier say they are
not going to overproduce for 2006. The cheaper brands I would expect it
from. ICP, GMP, Nordyne, maybe even throw soem extra ones down the Payne
assembly line. But the higher end manufacturers are looking forward to the
higher SEER's; ME too! We don't sell anything below 13 SEER for the most
part any way, although we did add-on to existing new coils 2 10's this week.

--
Bob Pietrangelo


www.comfort-solution.biz
On Time or Your Service Call is FREE
Preventive Maintenance Specialist




"SN" wrote in message
news:HQ01e.5834$Dz4.560@okepread01...
HeatMan wrote:
I'm sure by now you've read all the comments from everyone. I want to
throw
in my two cents worth....

As of January 2006, 13 SEER efficiency will be the law of the land for
AC's.
IF (caps intended) you don't replace it before then and it goes out
after
January 1, 2006, you'll have to pay considerably more for the 13 SEER
equipment.

Your call.

Just a clarification: As of Jan. 2006 only 13 SEER or above can be
MANUFACTURED, but anything manufactured before this date can still be
sold. So, lower SEER equipment will still be available for awhile.

My experience with replacing furnaces. Three years as an installer. It can
be done, to save the indoor coil. They are often right on top of the
furnace, so it's a bunch of extra work to do the "furnace only" replacement.
It may actually be easier to replace the furnace and the indoor coil as a
unit.

You can replace the outdoor unit (or not) at your leisure.

Of course, I can't see it from here. I'm going strictly by my experiences in
Rochester, NY. Which might not be relevant in your area.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"Walter E." wrote in message
news:1111699211.ceb1f890ed928c63dd22626c4727539b@t eranews...
I live in San Diego. House is 1600 sqft. My furnace is a 23 year old
Day&Nite 80,000 BTU unit. It uses a 3 ton split system air conditioner, also
23 years old.

The A/c sees very little use and is working fine. The furnace is getting
cranky and I would like to replace it.

Is it necessary or advisable to replace the a/c compressor and coil when I
replace the furnace?

Is there any cogent need to replace even the coil? After all, there is no
wear/tear on the coil. Can I just replace the pan under the coil when I
replace the furnace?

I realize that a new A/c compressor and coil would be more efficient but we
only use the a/c during an occasional hot spell, maybe 10 days a year.
--

Walter
The Happy Iconoclast www.rationality.net

Reasons to consider a new unit are, VS DC motors, 2 stage heat, the
possibiltity you are oversized, the instalation of a superior larger
size air filter, electric and gas savings in heat and cooling mode,
future repairs, and utility costs are going up .

VS or variable speed can run on a Humidistat Thermostat offered by
Carrier and Lennox and maybe others, that can be set to run at a very
low fan speed to remove double the humidity on days when cooling is not
the real issue but humidity is, this feature could lead to you using the
AC much more than 10 days a year to lower just humidity with minimal
cooling if that is an issue in your area. In heating mode you could run
on low-fan, low fire for more even heat, and air circulation through the
air filter. VS DC can take 2/3 to 1/2 the electric power of non VS DC
for running the fan normaly and even less on low, 1/4 the power.

Your old units blower fan is probably much less efficient than any new
unit and you will have electric savings in winter as well, but more with
VS DC. VS DC are more prone to failure so a 10 yr warranty, normaly
offered as an option would be necessary.

Get a load calculation in writing , from who ever you deal with, if
your heat and AC are oversized now proper sizing will give better
comfort winter and summer, especialy summer in humidity removal. To
large an AC and you cool but remain clamy, to much Btu heat and a to big
a blower and you heat to fast and uneven.

Humid areas realy need good humidity removal.

There are many good air filters out there that were not avalaible
years ago, that not only filter better on first pass air but last longer
due to their total size, so instead of monthly or so replacement it is
yearly.

Electric and gas is not going down in price, with the proper unit
sized and installed by a Pro new high effeciency equipment, and the
deterioration your unit has you could save 50%-60% ++ on electric and
gas in winter and 50- 80% ++ electric in summer on AC, and get more
overall comfort and control in living.

There are so many comfort options offered today that did not exist
years ago. At least look into them your options are endless.