Reverse cycle air conditioner size calculator

Check assessed cooling and heating loads against a quoted reverse-cycle air conditioner. A design load is the heating or cooling output the room needs at the assessed indoor and outdoor temperatures. It must come from an installer assessment.

Collect the unit cooling and heating outputs at those same conditions. Also collect the electrical input for each condition and your electricity price. Output is heating or cooling supplied to the room; electrical input is the power bought to provide it.

Use the exact model table, not just the largest number on a product page. The calculation compares the figures you enter. It does not create a room load from floor area, ceiling height or a general sizing rule.

Required cooling and heating capacity are the installer design loads. Capacity margin = manufacturer output at those conditions minus assessed load. Hourly electrical cost = manufacturer electrical input kW at that condition × electricity price. The tool does not create a room load from floor area or ceiling height.

Read cooling and heating margins separately. A positive margin means the entered output exceeds the assessed load by that amount. A negative margin means it falls short. Passing one condition does not establish that the unit meets the other.

The hourly cost prices the entered electrical input at that condition for one hour. It is not an annual bill or a prediction that the unit will draw that power continuously. Daily use and changing temperatures need a separate operating estimate.

Keep cooling data together and heating data together. Copy each load, output and input from the corresponding assessment or table column, with its temperature conditions. Check the units before calculating. A figure in watts must be converted to kW, and a yearly energy label cannot replace an input-power figure. These checks help avoid a plausible-looking but mismatched result.

These illustrative inputs are separate from your saved answers. Prices, use and performance are held constant for this worked scenario; they are not personal defaults.

Use an installer-assessed heating and cooling load and equipment output rated at the same temperatures. Mixing a room load at one outdoor temperature with a unit output at another does not give a matched comparison.

A maximum advertised output may differ from output at your design conditions. The calculator does not adjust the product table, add an automatic safety margin or infer performance between test points.

Keep all power figures in kW. Electrical input must not be substituted for cooling or heating output. Use the unrounded documented figures where possible; displayed money is rounded after the calculation.

These checks describe capacity at the conditions entered. They do not assess airflow, room layout, comfort, noise or installation suitability. Actual energy use varies as conditions and controls change. Incomplete edits keep the last valid result visible with a warning.

This Australian calculator prices electrical input using cents per kWh. Use the electricity price on your bill including applicable tax. Leave daily and monthly fixed supply charges out of that unit price.

Use local equipment documents for the exact unit and check the conditions beside each output rating. The sources explain the method and limits, rather than verifying your personal room loads. The result does not certify an installation or replace local requirements.

An installer must confirm cooling and heating capacity from the actual room loads and equipment performance. Take the room assessment and exact unit table so they can check both conditions together.

Ask them to explain any shortfall or margin, and review compatibility and installation scope. Use the appropriate qualified professional for electrical changes. Follow the maker instructions. A favourable capacity comparison is one check within the wider design decision, rather than approval to buy or install.