What Size Split System Do I Need? Your In-Depth Guide
Maximise comfort and save on energy bills by selecting the right size split system air conditioner. Learn how room factors affect sizing and see our handy, quick guide.
Split System A/C: What Size Do You Need?
Are you trying to work from home by day and binge-watch the latest Netflix series by night during the summer? If you don’t have air conditioning, or your unit isn’t keeping up, you’re likely having trouble concentrating and relaxing!
You need a new split system air conditioning unit to keep you cool all day long. But you’re probably wondering, “What size split system do I need?”
Picking the right size split system isn’t just about comfort—it’s about getting the most bang for your buck. Too small, and the A/C will struggle to cool your space, so you’ll be throwing money at energy bills for no reason. Too big, and you’ll have wasted money on the upfront cost of the unit!
How do you get it just right? Let’s break down what you need to know about choosing the perfect A/C size for your home.
Why Choosing the Correct Size Air Conditioner Matters
While it may be tempting to go with the cheapest split system you can find, it’s super important to focus on the system’s size instead.
Why?
Energy efficiency: An undersized unit has to work overtime, driving up your energy consumption and bills. An oversized unit will cycle on and off too quickly, also wasting energy.
Comfort levels: A system that’s too small to effectively cool/heat a room will leave you feeling uncomfortable, as will an oversized system because it can create uneven temperatures and excessive humidity.
Durability: Constantly starting and stopping a larger unit or overworking an undersized one shortens the system’s lifespan.
Less maintenance: Because properly sized systems experience less strain, less maintenance is required.
Noise levels: An improperly sized unit can operate loudly if it’s constantly straining to keep up.
Cost-effectiveness: The right-sized unit will save you money over time by balancing the upfront cost with long-term savings on energy and maintenance.
The 4 Main Factors That Affect A/C Sizing
1. Room Size
Open layout spaces, larger rooms, and rooms with ceilings above the average 2.4-metre height need a split system with a higher kilowatt (kW) capacity.
The system requires extra power to cool/heat the larger volume of air in the room and maintain a consistent temperature.
2. Insulation
Well-insulated rooms retain cool air in summer and warm air in winter, reducing the strain on an air conditioning unit. On the other hand, poorly insulated rooms allow cool/warm air to escape.
Insulation directly impacts A/C sizing because a poorly insulated room makes a system work much harder to maintain a comfortable temperature.
3. Windows
What type of windows and window furnishings affect room temperature and, therefore, A/C size?
Large or multiple windows can increase heat gain in summer and heat loss in winter.
Single-glazed windows offer less insulation than double-glazed ones.
Windows facing east or west may receive more direct sunlight.
Curtains, blinds, and external awnings can reduce the impact of room temperature.
4. Room Orientation
What kind of room orientation affects room temperature?
Rooms that receive more afternoon sunlight in the summer will always be warmer.
Rooms with more external walls may experience more temperature fluctuation.
Homes in hotter climates may require larger capacity units.
How To Measure Your Room
You'll need to measure your room to figure out what size air conditioner you need.
Measure the length and width of your room, then multiply these measurements to get the total area in square metres (m²).
If your room isn’t a perfect rectangle, break it into smaller sections (like rectangles or squares), calculate each area, and add them together.
If your room is open to another space (like a combined living/dining area), include that area in your total measurement, as your air conditioner will need to cover it, too.
Once you’ve calculated the total m², apply the rule-of-thumb of 1 or 1.5 kilowatts (kW) per 10m² to estimate the capacity you’ll need. For example, a 20m² room would require a unit with a capacity of 2.0 to 3.0kW.
What Size Split System Do I Need: A Quick Guide
Room Type |
Room Area |
Split System Size |
Small bedroom or study |
Up to 20m² |
|
Medium bedroom or small lounge room |
20–40m² |
|
Large bedroom, open-plan living area, lounge room, or kitchen |
40–60m² |
Remember, the size of the air conditioner needed depends on ceiling height. These estimates are based on a standard ceiling height of 2.4m. Your A/C capacity should be roughly 10% larger for rooms with 2.7m ceilings and 20% larger for those with 3m ceilings.
Outsmart the Heat With a Midea Split System
“What size split system do I need?”
As a general rule of thumb, 1 or 1.5kW per 10m². But as we’ve discussed, a lot of other factors come into play!
After browsing the Midea range of affordable, energy-efficient split systems with a generous 7-year warranty, consult a Midea expert about the right size for your room.
Call 1300 726 002 or complete this online form, and we’ll contact you soon!
FAQs About “What Size Split System Do I Need?”
How Do I Work Out What Size Split System I Need?
Multiply the length of the room by the width to determine the area in square metres (m²).
Multiply the room’s area by 1 or 1.5 kilowatts (kW) per 10m² to estimate the split system capacity you’ll need.
Consider additional factors. Rooms with ceiling heights above 2.4m, poor insulation, or large windows facing direct sunlight may need a higher-capacity unit.
What Size Room Will a 7kW Air Conditioner Cool?
A 7.0kW split system air conditioner will cool rooms measuring 50–70 m².
This capacity is ideal for larger open-plan living areas or spaces with high ceilings. However, insulation quality, ceiling height, window size, and sun exposure can influence the unit's effectiveness.
Is 2.5kW Enough for a Bedroom?
A 2.5 kW split system is suitable for rooms 17–25 m², making it appropriate for most standard-sized bedrooms.