What is the climate like? (Where do you live?) Note that unless you have really inexpensive electricity and net gas is available, it will cost less to use a furnace for heat and get a straight cooling system rather than a heat pump. Keep the ducts inside the house where it is at all practical.

What is location?

I would get a price on the XR17 two stage HP system. Price difference should be significantly less than the XL18i you were quoted. you do lose the extra 2 yr warranty on compressor snd Trane's proprietary funky top. I assume you are in an all electric system.

There is nothing wrong with reusing existing lineset as long as it is in good condition, flushed properly, and sized correctly.

I have no problem with flex duct for supply and return runs but please use metal for the trunk lines. Depending on location R8 at a minimum with mastic.

I like and have Trane's Perfect Fit media cabinet. Heavy duty and changeout is easy. Generic filters less expensive available at air filter companies.

XR15 and XR17 are also available from Trane's sister company Am Standard usually less expensive. You do want the TAM7 air handler for either of these outside condensers that delivers the best performance/efficiency numbers.

Nothing said about thermostat or heat strip size.

IMO

This post was edited by tigerdunes on Fri, Nov 28, 14 at 15:44

I am just southeast of the Raleigh,NC area.
Currently have a 3 ton Goodman CPLE heat pump, with R22 refrigerant,about 14 yrs old & 27 year old Carrier air handler, 40AQ036330EH, in attic of single story 2125 s/f brick house. Currently running on supp. heat since compressor died.

The heat strips proposed with both the XR15 and XL18 is BAYEVAC08LG.
The thermostat proposed for the XL18 is prestige IAQ and the XR15 just says digital programmable, no model number. How important is the thermostat? Your thoughts?

Do you still think it's worth looking at the 4 ton XR17 vs. 3.5 ton XR15? Will it make that much of a difference in energy costs savings? Other reasons?

I have two returns, one is in a hallway in the 8 ' ceiling and the other is on the high side wall of a cathedral ceiling, which I have to get the 8 foot ladder out for whenever I need to change that filter. If I get the media filter in the attic, I would have to go up in the attic via the pull down stairs, although I was told that filter would only need to be changed once a year. Is that true?
We'll be changing out the ductwork and the proposal states "replace supply & return plenums, replace 3 supply runs and 2 return runs with new high velocity return grille" and "mastic seal all new duct connections". Don't know size or type of ducts.

I am just southeast of the Raleigh,NC area.
Currently have a 3 ton Goodman CPLE heat pump, with R22 refrigerant,about 14 yrs old & 27 year old Carrier air handler, 40AQ036330EH, in attic of single story 2125 s/f brick house. Currently running on supp. heat since compressor died.

The heat strips proposed with both the XR15 and XL18 is BAYEVAC08LG.
The thermostat proposed for the XL18 is prestige IAQ and the XR15 just says digital programmable, no model number. How important is the thermostat? Your thoughts?

Do you still think it's worth looking at the 4 ton XR17 vs. 3.5 ton XR15? Will it make that much of a difference in energy costs savings? Other reasons?

I have two returns, one is in a hallway in the 8 ' ceiling and the other is on the high side wall of a cathedral ceiling, which I have to get the 8 foot ladder out for whenever I need to change that filter. If I get the media filter in the attic, I would have to go up in the attic via the pull down stairs, although I was told that filter would only need to be changed once a year. Is that true?
We'll be changing out the ductwork and the proposal states "replace supply & return plenums, replace 3 supply runs and 2 return runs with new high velocity return grille" and "mastic seal all new duct connections". Don't know size or type of ducts.

Forgot to mention, it is all electric.

Forgot to mention, it is all electric.

re: "Currently have a 3 ton Goodman CPLE heat pump, with R22 refrigerant,about 14 yrs old & 27 year old Carrier air handler, 40AQ036330EH, "

LOL, we still have a Carrier 40AQ036 cranking away in our crawlspace since 1983. They were really workhorses, weren't they? A couple of blower motors along the way (heat pump), but that's it, never a leak.

This post was edited by Dovetonsils on Sat, Nov 29, 14 at 19:05

I don't think that heat strip is large enough.

And I definitely would not go up in size without documentation that supports that decision, ie load calc.

What is size of your home? How did existing system perform?

Post back.

IMO

Tigerdunes,thanks for responding. House is 2125 s/f ranch. As stated above have 14 yr old 3ton Goodman R-22 heat pump with bad compressor. When it was working it seem to work well, except in extreme hot & cold would have to raise or lower thermostat to keep up and would run more. And you would feel cool air fist coming out of vents before heating. Never had a problem with air handler, 27 yr old Carrier, which is in the attic,except for a capacitor. The heat pump had condensor fan replaced, some capacitors, and last couple years had hard start on it.
I was also told the line set would not have to be changed on the XR15, but according to specs on net for 3 ton Goodman, it has 3/4 and 3/8 as opposed to specs on XR15 which is 3/4 and 7/8?
What size heat strip do you suggest?
Your thoughts on changing the 27 yr old ductwork. If so, size and type recommended. Same size as existing or is size of duct related to type system/size system installed?

Heat strip are usually sized to heating load, defrost function, and for emergency heat. If 3 ton, then minimum 10 KW which yield about 35 KBTUs.

As far as lineset size, you need to verify exactly what you have now.

I can't give you an informed opinion about your existing ductwork system. Request leak test.

You should be more comfortable with a completely matched system than what you have now not to mention the efficiency savings.

I prefer HP systems with EDD pls minimum 15 SEER and 9 HSPF.

IMO

Double check the lineset sizes (something doesn't sound right). You can get away with linesets that are slightly smaller than recommended at the expense of some efficiency. Usually only an issue for long lineset runs. This information on any efficiency loss should be available in the equipment installation manuals.

Homeowner has a mismatched system. The existing lineset size should be checked to the manufacturer's recommendation. I don't want a lineset that is sized close for a new system.

IMO

(Raleigh,NC area) It appears the existing line set size for old Goodman is 3/8" liquid and 3/4" gas. The proposed new Trane XR15 4TWR5042 requires the same size. I was looking at the 4TTR in error.
As far as heat strip size 8kw recommended, based on supp. needs of coldest day of year. Also would need to change wiring if 10 kw, currently have #4 aluminum wire. Load calc: heating 41,015 btu and cooling 39,884 btu---3.5 ton proposed for XR15. We have been running on supp heat now for about 2weeks now and it's very comfortable,and I'm assuming it can't be more than 8kw due to existing wiring. Also proposed thermostat is Honeywell PRO7000 and new ducts r-8 flex silver foil.
Your thoughts on sizing of heat pump and strips, thermostat, and duct type.

This post was edited by lin51 on Mon, Dec 1, 14 at 13:18

Sorry, 8 KW will not properly temper the defrost function AC air for a 3 or 3 1/2 ton HP condenser. And certainly will leave your comfort lacking if you ever require emergency heat. You are being advised incorrectly here. Does not matter to me. Just so you know.

I have no idea what your current heat strip size is. I would expect it to be comfortable with these mild and moderate days. Get a sweater though when it gets to the low 20s.

No all flex ductwork. Flex OK for runs but you want metal trunk lines for both supply and return. R-8 insulation OK. How many returns are planned? I would want 3 strategically located and correctly sized for 1500 CFMs.

As far as thermostat, HW Mdl 8321 same as Trane's 803 model.

Anything about a filter cabinet?

IMO

This post was edited by tigerdunes on Tue, Dec 2, 14 at 4:46