I've received three bids on replacing a 2.5 Goodman outdoor AC unit
that just died. Since we had a new Trane evaporator coil installed
with a new gas furnace last year, the consensus seems to be that we
should stick with a Trane AC unit to match the indoor coil. However,
advice from these 3 contractors (all of them recommended by friends)
on which Trane unit to install differs considerably:
Contractor A (the guys who put in our furnace last year) simply
recommended and priced a 12 SEER, R410A 2.5 ton unit over the phone.
Contractor B recommended either a 12 or 14 SEER 2 ton unit that uses
R22 refigerant. B also thought our 80,000 Btu furnace was oversized
for the house and offered to adjust (i.e., lower) the air flow to keep
the unit from heating the house too quickly and thus short cycling.
Contractor C recommended either a 12 or 14 SEER 2.5 ton unit that uses
R410A refrigerant. When I mentioned B's recommendation, he told me
that an outdoor unit using R22 would not properly match the evaporator
coil we now have, that "you don't want to mix oils." He didn't seem
to be concerned about the furnace being oversized.
I've read a good bit about the R410a vs. R22 debate, but my first
question is, should I even consider the R22 units, given the indoor
coil we have? In other words, is Contractor C right about the
inadvisability of Contractor B's proposal?
Secondly, none of these contractors made a thorough load calculation
before submitting a proposal (nor did Contractor A when he sized our
furnace last year). However, Contractor C did offer to do the full
J-Manual calculation once we accepted his bid. All other things being
reasonably equal, and presuming he's right about matching the coil,
I'm inclined to go with him for that reason. Is that a sound
If it helps, the coil model is TXC031C4HPCO/334158L5G; furnace model
is TUC080C942B8/3335XN87G. House is 1200 square feet, built in 1950,
brick veneer, with cathedral ceiling over kitchen and front room, and
single-pane double hung windows, located in central North Carolina.
Thanks beforehand for any advice!
Did he do a manual J?
If not, he has no clue.
Adjusting the airflow...IE, slowing it down, on an oversized furnace is not
only stupid, its out right dangerous.
Funny...your Goodman unit that just died used R22...therefore, replacement
with an R22 unit would be fine.
And while, no, you dont want to mix oils, there are ways to reuse the old
evap, and since if you go to a R410a unit, you have to replace the lineset
anyway, flushing the coil is simple....
Did HE do a manual J on the home to determine if the furnace is oversized?
No. He is not.
Also, it is my humble opinion, that with R410 still being in the infancy
stages, and having been down this road before with R500, R22 is a natural
choice for the time being. R22 will still be made when its time for your new
unit you are getting installed now to be replaced.
First, I am in Central NC too....would you accept a bid from me without a
full basis for the price quoted? If so...let me tell you that its gonna cost
$1500...UNLESS AFTER I do the manual J, it needs more, then it might be
You have NO way of knowing what you need.
Sounds like you are in Greensboro..LOL....we see this all the time up that
Manual J MUST be done BEFORE a bid is quoted. That way, both YOU and the
contractor know in advance what has to be done, and what size unit you need.
IF hes wanting to charge for it, as most of us do since that is time wasted,
and those of us that DO the calculations are tired of doing other peoples
homework, IF the contractor that does the calculations gets the job, he
should offer to take that off the final bill...be it $75, or $200.
Nope. Does not help a bit. See..in order to do a proper manual J, you must
know much more than that. It takes up to an hour to measure the home,
determine all the values that need to be done, and then, another 1 to 2
hours to calculate it all on paper.
Besides, Central NC has more than one value that is used to calculate your
load calc. If you are in Winston, its one value, Greensboro, another,
Charlotte area, still another...
Hows this....if you are in my service area, a free manual J, printed out,
and given to you? I dont sell Trane...dont want to..they make me too much
money as it is in repairs. IF you are interested...no strings..just offering
to help since thats why I got into the trade...you can call at the number
listed on the website, or e-mail me direct....I am in Davidson county...if
you are more than 50 miles out, there would be a small fee for time, but at
least you would have a second, unpartial opinion.
Websites listed at the bottom of my tagline.
Also, as more free advice....ignore anything that HVAC guy might say about
things...he isnt in the trade, and offers wrong and incorrect advice 99.9%
of th etime
You would be lucky to get CB to look at it, im 1500 miles away,
dont know him , but from posts here he will do it correct.
Unlike unlisenced Daves Heating and Hack Repair who thinks a
blower door test is putting foill tape on the air handler.
Yup...seen a few around here. One some idiot had gone to the local supplier
with his MVAC card, and gotten a can of R22 and filled it..
Now...try to explain to a guy that the refrigerant used is listed on the
info tag, its not R22, R22 will cause problems...and the start of the
problem is that the compressors toast...
Plus...they in general sucked.
This is Turtle.
After reading what you have said here. i feel like I'm in a chinese Fire Drill that
turned into a Real fire and they did not bring
Let me start at the beginning and define beginning and the end result.
First you accept no bids from contractor with out a Heat load calculation to see What
size unit as Cooling and Heat you Need. If the
contractor feels that he is going to run the heat load on the house for the other
contractor to use as what to bid on. They or most
will not submit a bid or heat load calculations first for others to use. I personally
will not submit a bid and a heat load
calculations with knowing the other contractor are going to see my calculations and
not have to spend the time to do the math for
the other contractors. More that 1/2 of the hvac installing contractor don't know how
to run heat load calculations to submit with
the bid and will want to suck off the real professional hvac installers that will
submit a heat load on the job. So Nobody Submits a
Bid without a Heat Load Calculations with it.
Secondly here All contractor A -- B -- C are making bids on something they have no
ideal of what you need. Would you call up a car
dealership and tell them to send you a car to buy and to use as for your use and the
dealership does not know anything about what
your needs is or what would be the right model for you. Asking a HVAC contractor to
submit a bid for some hvac work without them
running a heat load calculation and know what is needed would be the same as the
calling the car dealership and just tell them send
me a car to buy.
Thirdly Here You are asking for and getting bids for condenser only, 2.5 ton , 2.0
ton, 12 seer in each , 14 seer in each,
condenser + Evaperator coil , Condenser + Tubing Set + Flushing the evaperator coil,
Condenser 12 seer + Flush Evaperator coil,
Condenser Only 14 seer, and about 20 other combination that can be made out of what
the contractors have told you. So you want the
three contractor to put what type and size units / seer rating , and different type
of equipment in a combination of their choice
which is nothing more than a guess on their and your part and I can't see how you
expect any respectiable contractor to get serious
about doing your job. You have about 40 different combination to bid on and no one
will be able to bid on all the combination your
Fourthly here You need to call a HVAC contractor that will run a heat load
calculations on the home and you may have to pay him
for that service because of all the hacks out there that do not know how to run a
heat load calculations and hope they can bid a job
with the professional hvac contractor that has submitted a size and heat to bid on.
$75.00 to $200.00 is not out of line for a real
heat load calculation run on a home and really take all the information down and
really run the load correctly.
Now that the furnace and evaperator coil is only 1 year old. i would say all you need
is a condenser unit and / or a tubing set
change out if the tubing set is less than a year old don't change the tubing set. If
the tubing set is old change it out. The R-22
oil can be flushed easily enough to not cause a problem with going to the new 410-A
oil. The converting from R-22 oil to R-410-A oil
is nothing but a flush job.
Now if this job was my home. it would be R-22 going back in it for R-410-A has not
been around long enough to prove it'self yet. If
you want to be a part of the experiment of R-410-A , Be my guest. They are planning
on making R-22 too expencive to want to buy by
the years 2020 . If a system is properly installed and you get good equipment. you
will never need a drop of R-22 or any freon at
all for a life time of the unit. Now for a second note here is if R-22 gets too
expencive down the road. they have a direct drop in
/ replacement freon / R-407-C right now in freon to replace R-22 if it gets too
expencive. So your not left out in the cold if R-22
price goes to the moon. I will say your not making a screw up at all by still using
R-22 at all.
Now the fellow who wants to slow the air down to slow the heating of the home too
fast. That is a No No and you must have mistaken
him for saing that he would turn the gas pressure down to the lower end of the gas
pressure range to slow the heat down. Turn the
Gas pressure down but not the air volume down.
Now if you was happy with what you had in there. Put back what you had and be happy.
If you wanted to discuss anything here. post
bacxk an see.
Where do I send the bill for this job.
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