Separate the product, installation and electricity before comparing totals. Start with the system your room needs, then replace planning assumptions with a dated retailer price or itemised installer quote.
A portable unit is a supply-only buying decision. A split system is a property project. For planning, CoolCompare's current model starts a first indoor/outdoor split pair at £1,500–£3,000 before extra units, long pipe runs, electrical work, drilling, pumps, difficult access, urgency and VAT treatment are resolved.
Compare like with like. A product listing, a basic fitted pair and a surveyed multi-room design include different things.
| Route | What you are paying for | Cost evidence to use | Next step |
|---|---|---|---|
| Fan or shading first | Air movement or reduced solar gain, not refrigerant cooling. | Current product/material price and the room problem. | Check whether AC is needed → |
| Portable AC | Unit, delivery, exhaust hose and a secure window solution. | Exact retailer checkout total and source-checked electrical input. | Compare portable models → |
| Single split | Matched indoor/outdoor equipment, route, drainage, labour and commissioning. | Itemised site quotation; model allowance starts at £1,500–£3,000. | Plan installation → |
| Multi-split | Several room loads, compatible indoor units, outdoor capacity and multiple routes. | Room-by-room design and comparable surveyed quotes. | Design the rooms → |
| Ducted / whole-home | Air paths, grilles, controls, access and building work as well as equipment. | Property-specific design; a generic online total would be misleading. | Understand layouts → |
Floor area alone misses ceiling height, glazing, orientation, insulation, occupancy and heat from computers or cooking. An undersized unit can run hard while still missing the comfort target; an unnecessarily large product can add cost, noise and poor control. Use a capacity range, then check the exact model.
Calculate the room's BTU range →Ask whether the headline includes both indoor and outdoor units, brackets, vibration isolation, pipework, drainage, electrical work, access equipment, making good, commissioning, VAT and warranty registration. If an item is provisional, record what would change it.
Check a quote line by line →Cooling capacity in BTU/h or kW is not the same as electrical input. Running cost equals input power in kW × hours × tariff in £/kWh. Cycling, set point, weather and room heat gain change actual use, so a maximum-input scenario should be labelled rather than presented as a bill promise.
Use your watts, hours and tariff →Join purchase, installation, electricity and maintenance over the same number of years. Keep repair, replacement and future tariffs as explicit scenarios. A portable purchase may be cheaper today; a quieter installed system can be the more useful route for frequent, multi-season use.
Model three-year ownership →The survey should identify the cooled room boundary, indoor and outdoor positions, route length, wall construction, floor level, drainage fall, electrical supply and maintenance access. Flats can add freeholder or landlord permission and shared-fabric questions. Listed buildings, conservation areas and local planning constraints need property-specific checks.
Refrigerant work within the relevant F-gas rules must be handled by appropriately certified people and businesses. CoolCompare does not verify a company merely because it appears in a search result, and an online calculator is not an installation design.
The useful total depends on the system and scope. A portable unit is normally a product purchase plus delivery and a compatible window setup. A fixed split adds survey, equipment, installation, electrical and drainage work. CoolCompare uses a £1,500–£3,000 planning allowance for the first split pair before additional project drivers, not as a live quote or national average.
Not necessarily. Compare the delivered price, electrical input, hours used, room fit and likely ownership period. A poorly matched unit can run for longer without delivering the result expected.
No. BTU/h describes cooling capacity. Electricity cost should be calculated from electrical input in kW, operating hours and the tariff in pounds per kWh.
Ask for exact indoor and outdoor model codes, quantities, pipe route, drainage, electrical work, access, commissioning, warranty, VAT and exclusions. Compare the same scope rather than headline totals alone.
Planning assumptions reviewed 8 September 2026. The retained installation model is planning-model-1.1; it is not silently updated when a source changes. It is not a live quote or national average. Prices and project scope vary, so obtain itemised quotations and verify tax treatment before purchase.