Tools

Free, no-nonsense calculators. Plain tools for owners; technical ones for installers and pros. Every result is an estimate or a guide — confirm with a survey or check the current rules. No selling, no account, no email.

For owners

Room sizing calculator

Estimate the cooling/heating capacity a room needs.

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Running-cost calculator

What a unit costs to run, for cooling or heating.

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Unit converter

kW ⇄ BTU/h, m² ⇄ ft², °C ⇄ °F — instant, two-way.

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Grant eligibility checker

Regulated

Indicate likely UK grant eligibility for a heating system.

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Planning permission checker

Regulated

Is an outdoor unit likely permitted development? (England)

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Heating-cost comparison

Cost of useful heat: heat pump vs boiler vs electric.

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For installers & pros

F-gas leak-check interval

Regulated

Mandatory leak-check frequency for a refrigerant charge.

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TM44 applicability checker

Regulated

Is a TM44 air-conditioning inspection required?

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Advanced heat-load estimator

A fuller component-based pre-survey ballpark.

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