1.5 HP and 1.25 HP Air Conditioners: What Suits Your Room

1.25 HP suits a room of about ⁦15–18⁩ m² on a mid-level floor, and 1.5 HP a room of about ⁦18–21⁩ m². On a top floor with sun exposure, the ranges shrink by about 20%.

The calculation is based on about ⁦650 BTU⁩ per m², the basis of the calculator on our site:

• 1.25 HP (about ⁦12,000 BTU⁩): about 18.5 m² on a mid-level floor, about 16 m² on a top floor and about 15 m² on a top floor with a west-facing window.
• 1.5 HP (about ⁦13,500 BTU⁩): about 21 m² on a mid-level floor, about 18 m² on a top floor and about 16.5 m² on a sunny top floor.
• Ceiling above 2.8 m or a room open to a hallway: add about 10% more.

This size suits a master bedroom, a large study, a small living room in a ⁦2–3⁩ room apartment (Israelis count the living room as a room), or a top-floor bedroom where a 1 HP AC isn’t enough. For a living room of 20 m² or more, and certainly one open to the kitchen, a 2 HP AC is better.

The full table, from 1 to 5 HP, is in our guide on how many horsepower an AC needs, which also has a calculator.

Because most manufacturers in Israel jump from a model of about ⁦12,000–⁦12,400 BTU⁩⁩, labeled 1.25 HP, to a model of about ⁦15,000–⁦18,000 BTU⁩⁩, labeled ⁦1.5–2⁩ HP. So if you’re looking for ⁦13,500 BTU⁩, you have to decide which way to round.

Examples from the spec sheets we checked:

• Tadiran Air One INV 180: labeled 1.25 HP, ⁦12,180 BTU⁩.
• Electra Platinum INV 180: labeled 1.25 HP, ⁦12,300 BTU⁩, but the inverter range reaches ⁦13,500 BTU⁩.
• Tornado TOP J INV 18: ⁦15,013 BTU⁩ cooling, at about ₪2,590.
• Electra Relax Inverter 240: labeled 2 HP, ⁦16,241 BTU⁩.

On top of that, the number in the model name doesn’t always indicate capacity. At Electra, model 140 of the A Inverter series is 1.25 HP (⁦11,020 BTU⁩), and model 150 of the Platinum series is 1 HP (⁦9,600 BTU⁩). Even at the same store, the table and the spec sheet sometimes show different figures, so it’s important to read the cooling output line in BTU/h.

The rule: if your calculation comes out at ⁦12,500 BTU⁩ or less, a 1.25 HP model with a wide upper range will be enough. If it comes out at ⁦14,000 BTU⁩ or more, skip to a model of about ⁦15,000–⁦18,000 BTU⁩⁩.

Tadiran has several 1.25 HP models at about ₪⁦1,500–2,000.⁩ The main difference between them is efficiency and warranty, not capacity.

What we saw on the store pages:

• Tadiran Air One INV 180: ⁦12,180 BTU⁩, SEER 7, SCOP 3.9, Shabbat mode, WiFi and a 5-year warranty badge. Sells for about ₪1,650.
• Tadiran Galaxy INV-185: ⁦11,430 BTU⁩, SEER 6.12, SCOP 4.02 and WiFi. Per the page, the warranty is one year from the importer, and Shabbat mode isn’t mentioned. Sells for about ₪1,990, and the black version for about ₪1,565.
• The store’s list also includes the Alpha Pro INV 185X, at about ₪1,990, and the Supreme 180 INV, at about ₪2,170. We didn’t check their specs.

Bottom line: among the Tadiran models we checked, the Air One INV 180 gives the highest SEER at the lowest price. If you heat a lot in winter, also compare it with the Electra Platinum INV 180, which per the specs reaches a SCOP of 5.2. A full comparison between the two importers’ series is in our Tadiran vs Electra air conditioner guide.

For an ⁦18–20⁩ m² room on a mid-level floor, 1.25 HP with a wide upper range is enough. On a top floor, and from 21 m² up, about ⁦15,000–⁦18,000 BTU⁩⁩ is better.

Considerations based on what we saw in stores:

• Price: a 1.25 HP model costs about ₪⁦1,250–2,050,⁩ and a 2 HP model about ₪⁦2,230–3,400.⁩ The difference is about ₪1,000, plus about ₪400 in installation, because per pro.co.il (an Israeli contractors’ site) installing ⁦2–4⁩ HP costs about ₪⁦1,200–1,800⁩ compared with ₪⁦800–1,400⁩ up to 1.5 HP.
• Electrical: the 1.25 HP models we checked work with a 10-amp breaker. The Tadiran Air One INV 240, a 2 HP model, requires a 16-amp breaker per the specs. In an older home, check this with an electrician.
• Humidity: an oversized AC in a medium room reaches temperature quickly and removes less humidity. On the coast this feels like cold, sticky air.

If you’re right on the border, for example a 19 m² room on a top floor, consider the Tornado TOP J INV 18 (⁦15,013 BTU⁩) as a compromise between the two sizes.

Usually about ₪⁦2,050–3,450⁩: about ₪⁦1,250–2,050⁩ for the AC plus about ₪⁦800–1,400⁩ for standard installation.

Per pro.co.il, standard installation of an AC up to 1.5 HP includes up to 3 meters (10 ft) of copper piping. Each extra meter costs about ₪⁦120–140.⁩ Other common costs:

• Drilling through a concrete wall: about ₪⁦300–400.⁩ In a mamad (reinforced safe room) or thick wall, about ₪⁦600–900.⁩
• Dedicated AC outlet: about ₪⁦300–1,000⁩ per Tadiran, if there’s no suitable outlet.
• Extending the drain hose: about ₪⁦10–15⁩ per meter per Tadiran.
• Crane: about ₪250 per hour, when the outdoor unit is in a hard-to-reach spot.

Before ordering, make sure the installer is licensed and that the installation warranty is given separately from the importer’s warranty. Per Tadiran, the importer’s warranty covers the AC, and the installation warranty comes directly from the installer. Full details are in our AC installation cost guide.

If the AC is the room’s main heat source, compare the heating figure in BTU and the SCOP. Here the differences between models are bigger than in cooling.

What we saw in the spec sheets:

• Electra Platinum INV 180: ⁦13,100 BTU⁩ heating and a SCOP of 5.2. The best figures in the group.
• Tornado TOP J INV 16: ⁦12,966 BTU⁩ heating and a SCOP of 4.1.
• Tadiran Air One INV 180: ⁦12,180 BTU⁩ heating and a SCOP of 3.9.
• Electra Relax INV 170: ⁦10,966 BTU⁩ heating, lower than cooling, but a SCOP of 5.07.

A high SCOP means less electricity per unit of heat. In Jerusalem, Safed or Beersheba, where winter nights are cold, you’ll notice it on the electricity bill.

On very cold days the outdoor unit may go into defrost. Per Tadiran, if in heating mode the compressor is running, the fans stop and a light flashes, the AC is defrosting, and you need to wait about 10 minutes. It’s not a fault. The full explanation of the lights and remote symbols is in our Tadiran AC remote symbols guide.