Keep product, delivery, window accessories, installation, maintenance and electricity visible as separate costs.
A cheaper unit can cost more to own when delivery, a suitable window seal, installation work, maintenance and electricity are counted on the same timeline. This calculator keeps every input visible so two products can be compared on an identical use pattern. Enter prices you can evidence rather than a promotional saving or an assumed national average.
Purchase, delivery, accessories and installation normally happen at the start. Electricity and planned maintenance repeat. Keeping those groups separate shows whether a difference comes from the product price or the way it will be used.
Apply the same hours, days, weeks, tariff and duty-cycle assumption to each candidate. Rated power is a useful maximum-input comparison, but a compressor may cycle after the room approaches its set temperature. The tool therefore labels the estimate rather than presenting it as a bill forecast.
A portable unit may need a window kit or hose accessory; a split system needs a site-specific professional quotation. Do not compare a bare equipment price with a complete installed price. Record VAT, electrical work, access, commissioning and warranty terms separately.
The result does not predict future electricity rates, repairs, resale value or compressor behaviour. It is a planning scenario, not a retailer quote or a promise of savings. Recheck current prices and product power input at the source before purchase.
Method last reviewed 28 August 2026.