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AirGreen × TOSOT · Sold and installed by AirGreenThe Lomo 23 dual zone at AirGreenTwo rooms on one Lomo 23 compressor, from 18,000 to 42,000 BTU/h.
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TOSOT · Multi-zone · Lomo 23 dual zone · updated November 5, 2026

Lomo 23 dual zone: starting with a single head

The Lomo 23 compressor sheets allow a single head to start. Pick the compressor and the first head: you see what the sheet says about that head alone, and the possible pairs when the second one arrives.

Pick my first headBook my free estimate
  • 5Lomo 23 dual-zone compressors online
  • 1head at least, per the sheets read on October 28, 2026
  • 9,500 BTU/hheating for a single 9,000 head on the 36,000 Lomo 23
  • -21 °Cheating, per the TOSOT sheets
01 · One head now

Pick the compressor and your first head

What the sheet says about that head alone, then the possible pairs when the second one arrives, with your first head’s share.

Compressor · BTU/h

First head · BTU/h

TM24H4O with a 12,000 head: allowed to start per the sheet read on October 28, 2026; 3 possible pairs afterwards.

Lomo 23 · 24,000 BTU/hTM24H4O · AHRI 10064019
  1. AllowedA single head to startThe sheet gives a minimum of one head for this compressor.
  2. SheetThis head alone: no row publishedThe sheet’s table starts with pairs: no output published for this head alone.

When the second head arrives: the pairs the sheet lists

Second headSystem, cooling / heatingYour first head, cooling / heating
+ 9,00021,000 / 22,50012,000 / 13,000
+ 12,00024,000 / 26,00012,000 / 13,000
+ 18,00025,000 / 28,00010,000 / 11,200
See this compressor as a dual zone

TOSOT sheets for the Lomo 23 compressors, read on October 28, 2026; outputs at AHRI test conditions (95 °F cooling, 47 °F heating). A pale chip: head size not among this compressor’s combinations.

AirGreen × TOSOT

TOSOT Lomo 23 dual-zone units, live

Each product page: outdoor model, AHRI number and the heads offered.
02 · Did you know

Three things to know before starting small

01

One head is enough

The sheet for the 36,000 Lomo 23 compressor, read on October 28, 2026, says it outright: a single head is enough to run the system. It also gives the output of each head alone, from 9,000 to 24,000 BTU/h.

TOSOT sheet TM36H4O.

02

The first head can deliver less

On the 24,000 Lomo 23, the 12,000 + 18,000 pair gives 25,000 BTU/h in cooling: 10,000 for the 12,000 head and 15,000 for the 18,000 head, per the sheet read on October 28, 2026.

TOSOT sheet TM24H4O, combination table.

03

No ENERGY STAR record

Neither ENERGY STAR nor NEEP has a record for the AHRI numbers of the Lomo 23 multi-zone compressors, and Hydro-Québec’s list of October 7, 2026 gives them no LogisVert amount.

ENERGY STAR and NEEP (October 28, 2026); Hydro-Québec’s list of October 7, 2026.

03 · Side by side

The five Lomo 23 compressors as dual zones

The heads each sheet takes, and what it publishes for a single head.

CompressorHead sizesPairs listedSingle head publishedLine setCircuit
Lomo 23 · 18,000TM18H4O9,000 · 12,0003listed, no per-head output65 ft in total · 33 ft per headMCA 16 A · MOCP 25 A
Lomo 23 · 24,000TM24H4O9,000 · 12,000 · 18,0006no197 ft in total · 65 ft per headMCA 23 A · MOCP 30 A
Lomo 23 · 30,000TM30H4O9,000 · 12,000 · 18,000 · 24,0009no230 ft in total · 82 ft per headMCA 20 A · MOCP 30 A
Lomo 23 · 36,000TM36H4O9,000 · 12,000 · 18,000 · 24,00010yes, 4 sizes246 ft in total · 82 ft per headMCA 23 A · MOCP 35 A
Lomo 23 · 42,000TM42H3O9,000 · 12,000 · 18,000 · 24,00010no246 ft in total · 82 ft per headMCA 24 A · MOCP 40 A

TOSOT sheets read on October 28, 2026. MCA: minimum circuit ampacity; MOCP: maximum overcurrent protection.

04 · Multi-zone

The multi-zone pages, each with its question

R-410ADual zoneYour pair of heads, compressor by compressor.R-410ATri-zoneYour line-set plan, checked against the sheet.R-410AFour zonesFour heads against one compressor.R-410AFive zonesWhat TOSOT really publishes for five rooms.R-410AUltraHeat dual zoneWhat the compressor keeps in deep cold.R-410AUltraHeat tri-zoneThe head trios TOSOT accepts.R-410ALomo 23 tri-zoneThe compressor’s ceiling with three heads.TOSOTAll multi-zone unitsBoth compressor families, from 2 to 5 rooms.
AirGreen × TOSOT

The right model is chosen at your place, not on a grid

We look at the room, the insulation and the electrical panel, then we propose the model, the quote and the LogisVert amount that applies.

Book my free estimate514 316-2973
  • Sold and installed by AirGreenMontreal, Laval, Longueuil, South Shore and North Shore.
  • RBQ 5645-9605-01Subclasses 15.8 Ventilation, 15.10 Refrigeration and 16 Electricity.
  • LogisVertHydro-Québec never solicits by phone or door to door for LogisVert.
Sources

Sources and reading dates

  1. TOSOT, submittals TM18H4O, TM24H4O, TM30H4O, TM36H4O and TM42H3O, undated, read on tosot.com on October 28, 2026 (specifications and combination tables); these files were no longer online there on November 5, 2026.
  2. ENERGY STAR and NEEP: no record for AHRI numbers 10064017, 10064019, 10064021, 10064023 and 10064025 (searched on October 28, 2026).
  3. Hydro-Québec, “Heat pump search tool”, list of October 7, 2026 (LogisVert amounts).
  4. TOSOT, “Heat Pumps” brochure in English, undated: note on the 24,000 BTU/h size with the 42,000 BTU/h compressors.

LogisVert amounts come from Hydro-Québec’s list on the date shown; only Hydro-Québec confirms the grant. AHRI numbers are those on our product pages, unchanged.