How Far the Line Set Can Run, and When the Answer Is No
Seven Carrier variable-speed families, one tier, three different limits — and on two of them a run past a hundred feet is not permitted at all.
Most replacements put the new condenser where the old one stood, and the run that already worked goes on working. This guide is for the other cases: the unit moving to the far side of the house, the condenser going down by the garage, the air handler in an attic three storeys above it.
The manufacturers do publish a limit. What they do not publish is one limit.
One brand, one tier, three answers
These are seven Carrier families of the same tier — Infinity — and the same kind of machine, a variable speed compressor. The number is total equivalent length, with the units on the same level:
| Family | Refrigerant | Ceiling | Past the threshold |
|---|---|---|---|
| 24VNA9 · 25VNA8 | R-410A | 100 ft | not permitted |
| 27VNA0 | R-454B | 200 ft | no accessories needed |
| 24VNA6 · 25VNA4 | R-410A | 250 ft | accessories required |
| 27VNA1 · 27VNA3 | R-454B | 250 ft | no accessories needed |
A homeowner told that their equipment is “Infinity, variable speed” has been told nothing at all about how far it can be piped. Two and a half times separates the top of that column from the bottom, and the middle rows differ in kind rather than degree.
The row that matters most is the first one
On the 24VNA9 and the 25VNA8 the sheet does not say that a longer run needs extra parts. It says the unit is approved to 100 equivalent feet with no additional accessories, and that longer line set applications are not permitted.
That is a different sentence from the one on every other family here. Elsewhere “long line” is a threshold past which the installer adds accessories and carries on. On these two there is nothing to add. The run either fits inside a hundred equivalent feet or that model cannot be used.
The same two sheets restrict the drop as well. With the outdoor unit below the indoor one, the four and five ton builds are marked outside the acceptable range beyond seventy feet of vertical separation — not a longer allowance with conditions, simply out.
Vertical separation is limited separately, and harder
Length and drop are two limits, not one, and the drop is usually the tighter of the two. The 27VNA3 shows both traps at once: 250 equivalent feet on any size, but with the outdoor unit above the indoor one the five ton is allowed 200 feet of vertical separation and the three and four ton only 100 — a split printed inside a single cell of the table, easy to read past.
Below the indoor unit that family stops at 80 feet on every size. So the same model, the same length of copper, is fine in one direction and over the limit in the other.
Equivalent, not measured
Every number on this page is total equivalent length: the run plus an allowance for each elbow and fitting, because a bend resists flow the way extra pipe does. It is always more than a tape measure gives, sometimes much more on a run that turns a lot.
You cannot check this yourself, and it is the one number the limits are written against. It is a fair thing to ask an installer to show you.
Why this is not a refrigerant story
It would be tidy if the R-454B families were the flexible ones. Three of the four here are, at 250 feet with no accessories, and the two hard-capped families are both R-410A.
But the 24VNA6 and the 25VNA4 are R-410A too, and they reach 250 feet — the same ceiling as the newest units, with accessories. The refrigerant does not sort this column. The family does, which is the same answer this site keeps arriving at from different directions.
What this does not tell you
- It is seven Carrier families, not a rule for the brand and certainly not for the industry. Other Carrier families have their own numbers, and other brands publish their own tables entirely.
- It does not tell you what your existing run measures. Nothing on this site can; it needs the elbows counted.
- It says nothing about whether your copper can be reused. Length and diameter are separate questions from whether the line set stays, which is answered on the brand rules page.
What to ask your installer
- What total equivalent length are you calculating for this run, and what is the published ceiling for the exact model you are quoting?
- How much vertical separation is there between the two units, and which way — is the outdoor unit above or below?
- If the quote changes where the outdoor unit sits, does the new position still fit inside both limits for that family?
Questions people ask
How far can a line set run?
There is no single answer, even inside one brand and one product tier. Across seven Carrier Infinity variable-speed families the published ceiling is 100 equivalent feet on two of them, 200 on one and 250 on four. On the two capped at 100 the sheet does not say a longer run needs accessories — it says a longer run is not permitted.
What is equivalent length?
The straight distance plus an allowance for every elbow and fitting, because each one resists flow like extra pipe. It is always longer than what a tape measure gives you, and it is the number the manufacturer limits. Working it out is the installer job, not something you can do from the driveway.
My condenser is going where the old one was. Does any of this matter?
Usually not — a replacement in the same position inherits a run that already worked. It matters when the run is being changed, when the new unit is a different family from the old one, or when the outdoor unit sits well above or below the indoor one, because the vertical separation is limited separately and more tightly than the length.
Sources
- Carrier — 24VNA9 Infinity 19VS Variable Speed Air Conditioner — Product Data . Read 2026-09-02.
- Carrier — 25VNA8 Infinity 18VS Variable Speed Heat Pump — Product Data . Read 2026-09-02.
- Carrier — 24VNA6 Infinity Variable Speed Air Conditioner with Greenspeed Intelligence — Product Data . Read 2026-09-02.
- Carrier — 25VNA4 Infinity Variable Speed Heat Pump with Greenspeed Intelligence — Product Data . Read 2026-09-02.
- Carrier — 27VNA0 Infinity Variable Speed Heat Pump with Greenspeed Intelligence — Product Data . Read 2026-09-02.
- Carrier — 27VNA1 Infinity Variable Speed Cold Climate Heat Pump with Greenspeed Intelligence — Product Data . Read 2026-09-04.
- Carrier — 27VNA3 Infinity Variable Speed Heat Pump with Greenspeed Intelligence — Product Data . Read 2026-09-04.
This is a starting point, not an approval. Everything here is read from published manufacturer documents and dated, but only the licensed contractor who signs your installation can approve a specific system for your home and your local code. Take the citations on this page to them and ask.