I'm not sure our HVAC subcontractor (chosen by our contractor) is installing
the proper diameter line set and I was hoping someone would know what the
correct diameter is. We are adding an all new system (2nd zone) in the
attic and I lost confidence in the contractor when I heard the price (and
his justification for it) for replacing the older condenser and coil in the
Anyway, the condenser is a TCA230AK - Tempstar 2200 2.5 ton 12 SEER (13 SEER
with matching coil) and the run up to the attic is about 70 feet with a 20
foot rise and 5 90 degree bends. (Have I learned enough searching through
old posts in this group in the last 24 hours to at least ask the question
properly?) I believe the two lines he's using are 3/4" and 3/8" but, I
could certainly be off by 1/8". I've seen references to 1 1/8" lines for
longer runs on some equipment and this definitely isn't that large.
Is he using the right size? Are there any other important installation
issues I should be aware of?
Thanks in advance for any help.
You would have to reference the installation guidelines for that unit and I
don't have them handy. A comparable unit in the brand I sell recommends
3/4" up to 50' and 7/8" maximum for long line applications. You would
likely never see 1 1/8" on a 30,000 BTUH unit. The 3/8" line is correct
First, you are not going to get 13 SEER unless you use a 'Variable Speed'
Second, the oil charge is only good for 50', and the 3/8 - 3/4 line set is
good for up to 75'.
What's the numbers off the coil and furnace/air handler?
(get me those and I'll get you the actual SEER rating)
The coil EPM36B15CZ/Internation Comfort Products (Tempstar's parent company
right?) and the furnace/air handler is Tempstar/T8MPN075B1ZA1 (hard to read
the furnace number since it was underneath and only a few inches off the
floor). I noticed the furnace has an AFUE of 80 is this reasonable for a
suburban NYC area home (reasonably cold for 4 to 5 months a year). This
unit is heating/cooling about 1400 sq. ft. - 4 bedrooms & 2 baths and
Excuse my ignorance but, if the charge is only good for 50' does that mean
the installer has "add charge"?
If the 3/8 - 3/4 is good for 75' does that mean a 75 foot run of actual
tubing with or without bends or do 90 degree bends add extra "length" to the
Thank you very much for the info you've already provided.
First, UT (United Technologies) owns ICP (International Comfort Products)
which then markets several brands...
The figures you have been told are WRONG!!
The TCA230AKA condenser, EPM36B15C piston coil, and regular blower with
blower delay timer is rated for 11.0 SEER!
(BTW, In my opinion.....this is a stupid combination!)
The only way to get more is to use a TXV coil and a Variable Speed blower.
It'd be cheaper and perform better if you used a 10 SEER condenser with a
(living in NYC, you are not going to see a great deal of savings by
using/going to a 12 SEER unit)
Pay off would probably be in the 12-15 year range to start saving money in
Then the 80% furnace is another BAD choice! If I'm right you use heating the
majority of the time, and this is where you want the most efficiency you can
And the 92% is not a major upgrade. And you could very well see a savings in
little as 2-5 yrs easy.
I live in a warmer climate than you and haven't installed a 80% in like 1
1/2 - 2 years now.
(home furnaces that is)
But, one thing I think is being missed totally is a load calc, this is a
calculation that is performed to size the units according to your homes
(as I feel the 2 1/2 ton ac is larger than you need, this is a guess as I
haven't done a load calc on your home either)
E-mail me a copy of the prints and I could give you a quick calc to see if
it's even close.
(need the layout, measurements, windows, which way the house sits, low/high
temps, home winter/summer temps, insulation R values....)
If the line set is over 50', they have to add oil per the install
(which gives the amounts to add)
90's add to the overall length of run.
So, this means in order to achieve the rated SEER the suction line size has
to be increased.
Where did this contractor come from?
The contractor hasn't actually given any figures - I've been spending the
last day or so trying to figure out if he knows what he is doing and I saw
the Tempstar 12SEER condenser (13 with the correct coil according to
Tempstar's web site). The general contractor picked the hvac contractor and
my wife and I don't feel he's doing things right. We got suspicious when we
got a price of about $4500 to replace the downstairs condenser and coil in
an existing system. We're still not sure if the hvac contractor gave a high
price or if the general contractor marked it way up.
We live in the burbs outside of NYC. Summers are warm and humid more often
than not and A/C is used about 4 months a year. If we install a 13 SEER
unit (not sure if that's a simple rating off of the condenser or the whole
system's actual rating) we get a $300 rebate from the electric co. so,
payback may be sooner if the extra cost isn't too much more for 13 vs. 11
The unit is in the attic and we were told that the high efficiency units use
water lines that can freeze in the winter. This sounded a little strange to
me but I believed what I was hearing. Is this a bunch of bull? Winter
temps rarely go below 0 degrees F but occasionally they get into the
I love to but I don't have any prints and I really don't want you to go to
that much trouble. I can see what I really need to do is tell them to STOP
and have another contractor (of my own choosing) come in and evaluate the
Is there an easy way for me to tell the difference between 3/4" and 7/8"? I
saw in another post that a penny is 3/4" diameter and it appeared to be the
same size as the tubing but, I don't know how easy it is to see a 1/8"
Thank you VERY much for the quick and informative info. I really appreciate
Post a link to Tempstar's site that says it's a 13 seer rating with a
(for I'm a ICP dealer and their dealer site says NO, unless TXV & Variable
Then the 12 SEER unit is probably not a wise choice.
(all depends on electricity rates and usage)
92 % in my opinion, some areas require the unit to be in an inclosed room in
(all depends on the area)
Would be a wise move. Make sure the company did a load calc!
Measure the outside with a tape measure, the OD is the size of tubing.
(yes a penny is 3/4 while 7/8 is between a nickel and a quarter)
And the outside insulation on the line should also have the line size marked
Here's the link:
Please keep in mind I just assumed things were simpler than they really are
- I've learned alot in 48 hours. I guess the 13 SEER is a best case. Is
the combo he chose really bad? We did tell the general contractor we wanted
a quiet condenser. According to Tempstar's site the 2200 is quieter than
the 10 SEER units (2000 series I think). As long as we've got the 12 SEER
condensers we should certainly have the most efficient coils to go with it,
right? Is a variable speed motor an option on an 80% furnace?
See previous post, they assume the best equipment used.
My opinion, YES.
12 SEER....2 1/2 ton....72 db
10 SEER....2 1/2 ton....74 db
And if you find out that the unit is over sized the smaller units are
10 SEER....2 ton....72 db
10 SEER....1 1/2 ton....70 db
All of these units are pretty quiet, I wouldn't let that lean me one way or
If you want to gain the efficiency you spent the money on the condenser for,
(otherwise, you should go with the 10 & TVX, same SEER but less money, and
better coil control)
Yes, instead of a T8MPN it's a T8MPV....V or 'Variable Speed' option.
Never mind, they have it on their regular site....
'up to 13 SEER with the proper inside coil'
That in real life means.....this is the HIGHEST rating they can achieve out
of this unit using the highest quality units available to match up to it!
The real facts are that this unit is usually as follows....
11 SEER with piston coils
12 SEER with TXV coils
13 SEER with TXV & Variable Speed Blowers
The fact is that most people don't have VS Blower, so there goes the 13 out
(but they use it for marketing)
BTW, I still say you are better off with a 10 SEER & TXV.....for 11.0 SEER
(saving the upfront cost that are going to probably take 12-15 yrs to
How about the 80% furnace in the attic - if it turns out a 92% requires an
enclosed room I'd like to know if there an option on the 80% furnace for a
VS blower? If so would it sounds like that would be worth it.
How much extra is TXV and VS? If the $300 rebate covers a reasonable amount
of the extra cost I'd certainly do it.
Variable is avail in the 80, but if you don't plan to run the blower
constantly, I wouldn't opt for it.
(the 1 extra SEER just isn't worth it, in my opinion)
One thing for sure, if you go with VS Blower make sure you get a 10 yr parts
& labor warranty.
(for the VS motors are very salty to replace if it's not under the standard
5 yr warranty)
92% on the other hand is going to save you 12% in fuel cost, this is a major
What's your heating fuel cost per year?
If so it's going to save you roughly '$150-200' a year.
Very true, I just don't think if something has a 10 yr payback that it is
But, one never knows what inflation is going to do and how quick it's going
to do it.
But one thing is for sure, he needs more efficiency on the heat side than on
(for the heating is the more used appliance in his area)
It was too late and too dark to check the line set last night but I looked
this morning and it's definetely 3/4". Thanks for the tip about the
diameter being written on the insulation - I kept looking at the tubing
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