GOODMAN//Multi-zone//3 zones
Goodman 3-zone heat pump: three refrigerant lines, one outdoor unit
The 27,000 and the 36,000 take three heads. Before the heads comes the route: GOODMAN publishes a maximum length per line and for the whole system, and asks for extra refrigerant beyond the precharge. Enter your three lengths and the tool does the sums.
The question this page answersThree rooms on one outdoor unit: do the line lengths and the charge work?
The two Goodman tri-zone systems in our store
The 27,000 comes in five variants, the 36,000 in ten: one per trio of heads. Each product page leads to a price request.
Tool//Line plan
Your three refrigerant lines against GOODMAN's limits
Enter the length of each line, from the head to the outdoor unit, in feet (the tool also gives the total in metres), then the head in each room. The tool checks each line against the per-head limit and the total against the system limit, works out the refrigerant to add beyond the precharge and tells you whether the trio is published.
Three lines on the 27,000
MST273E21MCAA, heads 9,000 + 9,000 + 12,000
Length enteredLimit per line (98 ft)Full bar: 197 ft, the total allowed
- Total length
- 105 ft32.0 m
- Beyond the precharge
- 31.2 ftprecharge for 73.8 ft
- Refrigerant to add
- 5.0 ozabout 142 g
Within the published limits. No line exceeds 98 ft, and the total stays within 197 ft.
Trios published on the 27,000
Trio published by GOODMAN on the 27,000. It is sold as a variant.
See the 9 + 9 + 12 variantAll four bars share one scale: zero to the total the outdoor unit allows. The brochure does not say whether the precharge covers the total or each line; the tool applies it to the total. Read per line (24.6 ft each), it can call for more refrigerant: on the 27,000 when a line is shorter than 24.6 ft, on the 36,000 as soon as a line is longer, since its fourth port stays free. The final charge is set at installation. Height differences are not calculated here; metres are a conversion of GOODMAN's feet. GOODMAN's table covers wall and ducted heads; the variants we sell are wall heads.
GOODMAN//Line set
Line limits of the 27,000 and the 36,000
What GOODMAN prints for the refrigerant lines of its two outdoor units with three zones or more, in the 03-21 brochure and its 06-21 revision.
| Published value | 27,000 | 36,000 |
|---|---|---|
| Outdoor unit | MST273E21MCAA | MST363E21MCAA |
| Number of heads | 2 or 3 | 2 to 4 |
| Maximum length per head | 98 ft | 115 ft |
| Maximum total length | 197 ft | 262 ft |
| Maximum height difference, outdoor unit to head | 49 ft | 49 ft |
| Maximum height difference between heads | 33 ft | 33 ft |
| Refrigerant precharge for | 73.8 ft | 98.4 ft |
| Additional charge | 0.161 oz per foot | 0.161 oz per foot |
| Factory charge | 98.8 oz of R-410A | 105.8 oz of R-410A |
Where the documents disagree, we picked one value and say which. Lengths: the table follows the 03-21 and 06-21 brochures, which agree; the 2018 French-language document gives 30 and 35 ft per head, 148 and 197 ft in total. We keep 2021, the more recent. Precharge: 73.8 and 98.4 ft in the 03-21 brochure and the 2018 document, rounded to 74 and 98 ft in the 06-21 revision; we keep the decimal.
GOODMAN//27,000 or 36,000
Three rooms: what sets the 27,000 apart from the 36,000
Both outdoor units take three heads and have the same dimensions. Two differences matter.
Five trios versus ten
On the 27,000, GOODMAN publishes 9 + 9 + 9, 9 + 9 + 12, 9 + 9 + 18, 9 + 12 + 12 and 12 + 12 + 12. The 36,000 takes the same five and five more: 9 + 12 + 18, 9 + 18 + 18, 12 + 12 + 18, 12 + 12 + 24 and 12 + 18 + 18 (source 1, p. 7).
One free port on the 36,000
The 27,000 has three ports, all used by three heads; the 36,000 has four, and one stays free with 3 zones (source 1, p. 7). If its 98.4 ft precharge is read per port, the 24.6 ft meant for that fourth port goes unused (AirGreen calculation).
Compare//The 36,000, two uses
The 36,000 with 3 or 4 zones: the line set
Same outdoor unit, same length limits. What changes is each line's share. GOODMAN values from source 1, p. 7; the marked rows are AirGreen calculations.
| On the MST363E21MCAA | 3 zones | 4 zones |
|---|---|---|
| Refrigerant lines | 3 | 4 |
| Maximum length per head | 115 ft | 115 ft |
| Maximum total length | 262 ft | 262 ft |
| Average per line at the maximum total (AirGreen calculation) | 87.3 ft | 65.5 ft |
| Precharge for | 98.4 ft | 98.4 ft |
| Refrigerant to add with 40-ft lines (AirGreen calculation) | 3.5 oz for 120 ft | 9.9 oz for 160 ft |
The calculations read the precharge against the total, as the tool does; read as 24.6 ft per line, the tri-zone with three 40-ft lines would need 7.4 oz. See the 4-zone page.
Did you know//GOODMAN documents, AirGreen sums
Three line-set figures to know before drilling
With three heads, the total limit rules
On the 27,000, three lines at the per-head maximum (3 × 98 = 294 ft) run 97 ft over the 197 ft allowed in total; on the 36,000, 3 × 115 = 345 ft against 262 ft allowed (AirGreen calculation). With three rooms, the total limit is the one to check first.
Source 1, p. 7; source 2, p. 724.6 ft of precharge per port, on all three units
GOODMAN precharges the 18,000, 27,000 and 36,000 for 49.2, 73.8 and 98.4 ft: 24.6 ft (7.5 m) times each unit's number of ports (AirGreen calculation).
Source 1, p. 712 + 12 + 24 yes, 9 + 9 + 24 no
On the 36,000, the only trio with a 24,000 head is 12 + 12 + 24. The smaller trios 9 + 9 + 24 and 9 + 12 + 24 are not published.
Source 1, p. 7; source 3, p. 9AirGreen × GOODMAN//Who does what
From GOODMAN's table to the job site
What GOODMAN brings
- The 27,000 and the 36,000, two outdoor units that take three heads
- Published maximum lengths per line and for the whole system
- A factory precharge and an additional-charge rule
- The allowed height differences, to the outdoor unit and between heads
What AirGreen brings
- An on-site survey of the three routes, floor by floor
- Refrigerant lines and charge by our refrigeration technicians, under AirGreen's RBQ licence 5645-9605-01
- The choice between the 27,000 and the 36,000 for your three rooms
- One quote for the outdoor unit, the three heads and the line set
Questions//3 zones
Questions about the Goodman tri-zone
How much refrigerant line can you run for three rooms?
According to GOODMAN's 2021 brochure: on the 27,000, up to 98 ft per line and 197 ft in total; on the 36,000, 115 ft per line and 262 ft in total. Both limits apply together: once the total is reached, every extra foot on one line comes off the other two.
Does refrigerant need to be added?
Only beyond the length covered by the precharge: 73.8 ft on the 27,000, 98.4 ft on the 36,000. Three lines of 25, 35 and 45 ft on the 27,000 run 31.2 ft past the precharge, that is 5.0 oz at 0.161 oz per foot (AirGreen calculation). Since all three lines are longer than 24.6 ft, the result is the same whether the precharge is read against the total or per line.
One head in the basement and one upstairs: is that allowed?
Yes, as long as the height differences stay within GOODMAN's limits: 49 ft (14.9 m) between the outdoor unit and a head, 33 ft (10.1 m) between two heads. We measure the real heights on site before proposing the route.
Is a tri-zone outdoor unit noisy?
GOODMAN publishes 63.4 dB(A) for the 27,000 and 62.3 dB(A) for the 36,000, without stating the measuring distance. In Montreal, noise and installation-permit rules change from one borough to the next, and the City asks you to contact your borough before you apply. We choose where the outdoor unit goes with you.
Does the Goodman tri-zone qualify for Hydro-Québec's LogisVert financial assistance?
No. Since November 26, 2025, Hydro-Québec requires an ENERGY STAR certified heat pump, and neither the 27,000 nor the 36,000 is in the ENERGY STAR list read on November 5, 2026. GOODMAN's 2018 French-language document marked the 27,000 "OUI" (yes) and the 36,000 "NON" (no) for ENERGY STAR; we go by the current list, the one Hydro-Québec requires.
Read next//The GOODMAN space
For one, two or four rooms
Three rooms: we start by measuring the routes
The lengths entered in the tool are estimates. On site, each real route is checked against GOODMAN's limits, per line and in total, and the refrigerant to add is worked out from those real lengths.
Sold and installed by AirGreen.Montreal, Laval, Longueuil, the South Shore and the North Shore.
An AirGreen technician assesses the heating and cooling needs, where the units will go and the refrigerant line route on site before proposing a model.
Subclasses 15.8, 15.10 and 16. Gas and oil work is done by a partner holding the required licence.
The equipment is GOODMAN-branded. AirGreen sells it, installs it and services it across Greater Montreal.
Sources
- GOODMAN, "Heat Pump and Air Conditioner Ductless Units", 19 Series and 21 Series, code CB-DL-1921S-HP 03-21, p. 7. GOODMAN document kept in AirGreen's files.
- GOODMAN, same brochure, revision CB-DL-1921S-HP 06-21, p. 7.
- GOODMAN, "Thermopompe et climatiseur simple et multizones" (French-language document), code CB-GDuctless2018-FR 10.18, p. 9 and 11.
- ENERGY STAR, certified heat pumps (dataset w7cv-9xjt), Canadian market, read November 5, 2026. energystar.gov
- Hydro-Québec, "LogisVert Efficient Homes Program – ENERGY STAR® Heat Pump", partner notice of September 25, 2025 (required from November 26, 2025). hydroquebec.com
- City of Montreal, permit page for installing a heat pump or an air conditioner (French-language page), updated August 3, 2026, read November 5, 2026. montreal.ca
Read and dated by AirGreen. Capacities and limits are the ones GOODMAN publishes; a real installation can give other values.