Home & Lifestyle buying guide

How to choose an air conditioner

An air conditioner that is too small runs constantly and never cools the room, while one that is too big cycles on and off and handles humidity poorly. Size it to your room and climate first, then compare official energy labels and installation quality, which matters as much as the unit itself.

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Weighted criteria

What matters when choosing air conditioners

Weights add up to 100 and reflect how much each factor usually decides satisfaction. Change them to fit you in the scorecard.

  1. Right capacity for the room

    25%

    Cooling capacity (tons, BTU or kW) matched to room size, sun exposure, ceiling height and occupancy.

    How to check: Use a sizing calculator with your room details and confirm with the installer.

  2. Energy efficiency label

    25%

    The official rating: BEE star label and ISEER in India, ENERGY STAR in the US, the EU energy label with SEER in the EU.

    How to check: Read the label on the unit and look the model up in the official database where one exists.

  3. Installation quality

    20%

    Correct mounting, piping length, sealing and drainage affect efficiency and noise.

    How to check: Ask what the standard installation includes and what extra piping or brackets cost.

  4. Inverter & humidity control

    10%

    Inverter compressors adjust speed instead of switching on and off, which usually saves energy over a season.

    How to check: Check whether the model has an inverter compressor and a dry or dehumidify mode.

  5. Refrigerant type

    10%

    Newer refrigerants have lower global warming potential.

    How to check: Check the refrigerant on the label and whether local technicians can service it.

  6. Service & spares

    10%

    Availability of trained service and parts in your area.

    How to check: Confirm service coverage and the compressor warranty terms in writing.

Avoid

Red flags

  • No official energy label on a model that should carry one.
  • Very low price that excludes installation, piping and stabiliser.
  • Air-purifying or health claims for the indoor unit with no test data.
  • Gas top-ups sold as routine maintenance on a new unit (a leak is a fault).

Before you pay

Checklist

  1. Measure the room and note sun exposure.
  2. Work out the capacity you need.
  3. Compare official energy labels for that capacity.
  4. Get the installation scope and extra costs in writing.
  5. Check refrigerant type and local service.
  6. Estimate running cost from the power rating and your tariff.

Ask the seller

Questions to ask

  • What does standard installation include, and what costs extra?
  • How long is the compressor warranty, and what conditions apply?
  • Is the energy label the current one for this model year?

After you buy

Warranty & returns

Air conditioners commonly carry one year of full cover with longer cover on the compressor; conditions often require authorised installation.

  • Keep the installation invoice.
  • Schedule servicing as the warranty requires.
  • Get compressor warranty terms in writing.

Track the return window and warranty end date

Common mistakes

Myths vs facts

Myth Bigger capacity always cools better.

Fact An oversized unit short-cycles, wastes energy and leaves the room clammy.

Myth Setting the thermostat very low cools the room faster.

Fact Most units cool at the same rate; a very low setpoint just overshoots and wastes energy.

Where this comes from

Official sources

Criteria and weights are AltFTool's editorial judgement, not a statement by these bodies. This guide is general consumer information, not professional advice.

FAQ

Air Conditioners: common questions

What is ISEER?

In India, ISEER is a seasonal efficiency measure used for BEE star ratings on air conditioners. A higher value means less electricity for the same cooling over a typical season.

Window or split?

Split units are usually quieter and more efficient. Window units are simpler to install and suit some rentals.

How often should an AC be serviced?

Clean filters regularly and follow the maker's service schedule, usually before the main cooling season.

Free tools

Use these with this guide

Weighted scorecard

Review pattern checker

Complaint letter writer

Warranty & returns tracker

True cost calculator

Also handy: ac tonnage calculator, electricity bill calculator

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