Enter the number and size of rooms to compare units, estimated electricity use, annual cooling cost and installation complexity.
| System route | Indoor / outdoor units | Cooling | Annual electricity | Annual cooling cost | Planning |
|---|---|---|---|---|---|
| 4 single-split systems | 4 / 4 | 8 kW | 400 kWh | £100 | Higher |
| One multi-split system | 4 / 1 | 6.8 kW | 429 kWh | £107 | Moderate |
| 4 portable air conditioners | 4 / 0 | 8 kW | 692 kWh | £173 | Low |
| Air-to-water heat pump + separate cooling | 4 / 2 | 8 kW | 429 kWh | £107 | Higher |
Strong room-by-room control and redundancy, but the largest outdoor-unit count and visual/noise planning burden.
Usually the clearest permanent multi-room cooling route where outdoor space is constrained, subject to pipe runs and simultaneous-load design.
Avoids permanent installation, but needs safe window exhaust routes in every room and uses more electricity for the same useful cooling.
A whole-home heating and hot-water route, but standard radiator-based air-to-water systems do not replace room air conditioning.
This is an early-stage capacity and electricity model, not a heat-loss calculation or installation quotation.
Confirm outdoor-unit positions, noise assessment and local planning conditions before ordering.
Reversible splits can heat rooms, but they do not normally provide domestic hot water.
A multi-room plan must explain which rooms are served, when they operate together and where heat, pipework, condensate and sound will go. Counting indoor units alone is not a design.
Bedrooms used overnight, a daytime office and a highly glazed living room may peak at different times. Record individual dimensions and exposures, then ask whether the proposed outdoor unit can serve the credible coincident load.
Several single splits can provide independent operation but require more outdoor units. A multi-split reduces outdoor-unit count but creates shared capacity and routing questions. Portable units avoid refrigerant installation but require a suitable exhaust opening in every served room.
Air-to-air heat pumps normally do not provide domestic hot water. An air-to-water proposal may cover heating and hot water but needs a separate, explicit cooling route where cooling is required.
Limit: Indicative capacities and costs cannot replace room-by-room heat-loss and cooling-load calculations, acoustic evidence, electrical design, planning checks or a site survey.
Figures are illustrative and reviewed 10 August 2026. Confirm the current position for the nation, property and proposed installation.