Skip to main content
Chillin Air & Electrical
Switch to dark mode
Back to Split Systems

What Size Split System Do I Need?

The right split system size depends on your room area: 2.5kW for bedrooms up to 20m², 3.5kW for medium bedrooms up to 30m², 5kW for living areas up to 50m², and 7kW for large open-plan areas up to 70m². But ceiling height, insulation, window size, and which direction the room faces all affect the actual requirement.

Why sizing matters

Too small and the unit runs at full capacity constantly, struggling to reach the target temperature and burning more power. Too large and it cools the room too fast without removing humidity — the room feels cold but clammy. **The golden rule:** it's better to slightly oversize than undersize in Queensland. Our humid climate means the unit needs to remove moisture as well as heat, and an undersized unit can't keep up on a 35° day. **Factors that increase the size you need:** - Large windows facing west or north - High ceilings (over 2.7m) - Poor insulation (common in pre-2000 Queenslanders) - Open stairwells or hallways that let air escape - Upper floor rooms (hot air rises) When in doubt, go up a size. The price difference between a 2.5kW ($1,400) and a 3.5kW ($1,550) is $150 — less than the cost of replacing an undersized unit that can't cope.

Pricing

SizeBest ForPrice
2.5kWBedrooms, studies (up to ~20m²)$1,400
3.5kWMedium bedrooms, offices (up to ~30m²)$1,550
5kWLiving areas (up to ~50m²)$1,995
7kWLarge open-plan (up to ~70m²)$2,245

All prices supplied & installed, inc GST. Prices are final for standard back-to-back installs.

12-Month Workmanship Guarantee

Every Chillin installation is backed by our guarantee. Hisense 7-year manufacturer warranty included.

Book Your Install

Frequently Asked Questions

Can one split system cool my whole house?

No. A single split system cools one room or one open-plan area. For whole-home cooling, you need either multiple split systems, a multi-split system (one outdoor unit, multiple indoor units), or ducted air conditioning.

What if my room is between sizes?

Go up. An oversized unit handles the load better and cycles less, which is better for the unit's lifespan. An undersized unit running flat out all day is worse for both comfort and running costs.

Do you help me choose the right size?

Yes. When you book, tell us the room size and we'll confirm which unit is right. For standard rooms, the sizing guide above is accurate. For unusual spaces, we'll advise before installation.

Does ceiling height matter?

Yes. The sizing guide assumes standard 2.4-2.7m ceilings. If your ceilings are higher (common in Queenslanders), you'll need a larger unit or accept that the unit will take longer to cool the space.

Trusted by Queensland homeowners since 1991. Call 07 3801 3269.