Hi, my AC condenser unit (3ton) is 19 years old so I decided to replace it
before it fails.
Is it a reasonable idea to replace the unit with a heat pump thereby giving
me a new AC unit and dual heat systems, gas and heat pump?
Your thoughts and ideas would be greatly appreciated.
JenTra Winston Salem, NC
That's what we did in February. It has been a good decision,
especially with the price of natural gas sky-rocketing. When we had a
gaspack, with only gas heat, our gas bills would sometimes reach $200.
The latest bill received yesterday was $53. Our nighttime
temperatures have been in the teens and twenties. Our last electric
bill was $103, so our total energy bill was $156. That's around $100
less than it would have been with the gaspack. The gas comes on only
in the morning at 7:00 A.M. when we bring the house temperature back
to 72-degrees. If there is a 3-degree differential between the
thermostat setting and actual temp, the gas comes on for a short time.
Between 6:00 P.M. and 10:00 P.M. we raise the temp to 74-degrees. We
are aware that we could cut our costs considerably if we went no
higher than 68-degrees.
Be aware that a dual-fuel heatpump is a lot more expensive than just a
plain A/C. And there aren't very many of them on the market. After a
lot of investigating, we ended up with a Trane.
Dick - Prescott Arizona
Cant do that.
A heat pump meters differently than straight air. You are wasting your money
to do that.
When it goes into heat mode, and the flow of refrigerant is reversed, the
metering will not even be close to right, particularly on a 20 year old
system. So much has changed in the last 5 years alone, only a fool or a
crook would install a heat pump like you suggest to ANY existing units coil.
Yes, they are excellent systems, but (at the very minimum) you'll have to
install a different thermostat, new low voltage wiring, and a control system
to shut the gas furnace off when the outside heat pump is running. You'll
also probably have to change the inside refrigerant coil and raise the
outside heat pump unit. If you're going to replace the inside coil, then you
might as well replace the gas furnace. The new inside coils fit nicely above
the new gas furnaces, and that means less labor. Plus, new furnaces can be
much more efficient.
With a heat pump, you'll probably average 90 to 95 degree air out your
registers, so if your duct work is undersized, you may feel uncomfortable
when it's running. Talk to at least 3 HVAC contractors, and go with the one
who explains things the best, and who returns your phone calls. Price
doesn't have a lot to do with the quality of the workmanship. Some brands
can be more expensive, like Trane and Carrier. IMO, they aren't worth it.
Stay away from builder grade units like Goodman & Janitrol.
It is done all the time. It is, in this climate (Central NC) the cheapest
form of heat you can have.
This season alone, we have already installed over 10 systems like you are
talking about, HOWEVER, its not a deal where you just get the contractor to
switch out the outer unit.
You have several options.
You can leave your furnace, provided that the unit has enough airflow to be
matched to the heat pump. In this case, you add a new evap coil matched,
with proper metering to the new outdoor unit, and a dual fuel control. The
thermostat will also need to be replaced, and more than likely, new
thermostat wiring will need to be ran. A new linset is almost maditory, and
the electrical to the outer unit may need to be upgraded.
You can replace it all, including the furnace for max efficienty. Chances
are that your 19 year old setup is on its last legs anyway, and the time is
now, before everyone runs out of the 10-11-and 12 SEER rated units to get a
bargan on the parts required to do this. In this case, it will cost a bit
more, but you have a full warranty on the equipment. It would really suck to
find out that right after you drop a few grand on a new heat pump
installation, that your 20 year old furnace isnt up to the task.
You can also go straight electric. Remove the gas unit, and go to an air
handler, with electric backup, and a new heat pump. In this case, you will
have to upgrade the electric to the air handler, and if your homes main is
close to max, it will need to be upgraded to handle the strips. The
installer you chose will be able to look at it, and tell you if this is the
It is also the cheaper way to heat your home here.
Depending on the manual T (the load calculation that MUST be done to insure
proper heat pump sizing) , and the SEER rating of the unit you pick, your
current furnace also may not have enough airflow to work with the heat pump.
Keep this in mind.
Also, keep in mind, that your existing ductwork may not be suitable for a
new higher airflow unit. Your contractor should check this to make sure this
is, or is not the case.
Anyone that does not, you need to show to the door. Replacing a straight air
unit with a heat pump is not as simple as looking at the old unit, in this
case, 3 tons, and saying, ok, you need a 3 ton heat pump.
You need to insist on a few things:
Make SURE your installer pulls permits, and gets the inspections. It is
illegal for them not to.
If he is not licenced as an electrician, and most are not, there will be
electrical permits pulled by a licenced electrician in addition to the
Make SURE your installer is insured.
Make sure your installer is licenced.
Prices will vary, and can vary greatly. Depending on the make, and model of
the unit that you pick, prices can range from (very roungh estimate without
being able to see it, and know what you are going to do) under $2500 for a
real hacked in job, to as high as $6,000 or more for a 18+SEER unit.
Also, keep in mind that many contractors there in Winston are charging for
estimates now. We are in direct competition with most of the guys there, so
I wont name names, but you need to call around, and ask.
Ask if they do the proper load calc, ask if the estimates are free, or how
you get refunded for the estimate charge should the job be awarded. Ask for
a copy of the insurance. Ask for licence numbers. Make SURE that the licence
number matches the name of the company IF you are using a referral from a
friend. Ask how long the service agreement is for. Ask if you even get one.
Ask if extended warranties are available for your unit. Ask for referrals if
you doubt and if you doubt, I might suggest NOT using the guy, or company.
Expect NOT to get fitted right in. Any contractor in this area right now
that is worth anything is buried. Ask for a QUOTE, Not an estimate.
Estimates can vary greatly, and NC law allows for this. You can get an
estimate for $3000 and then get a bill for $3500 and its legal.
With a hard quote, they can only charge more for unseen issues, with a
signed change order.
Try not to deal with a salesperson. I dont even hire sales guys. Sales guys
know one thing: Sign Here. I hate em. They tend NOT to know what to look for
when sizing one out, they tend NOT to take the right calculations and then
size it right..they just want you to sign the bottom line.
Ask who is going to come out, ask who is going to insure the installers do
the job correctly. The inspections department only checks for code issues,
not installation issues related to a unit, unless its a direct code issue.
Remember that the name on the unit means little, its the install that will
make you happy with the money you spend.
And yes...im in your area, (Davidson) and as always, estimates for NG
members are free.
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