G'day! When you're looking to cool a small room, it's tempting to think "smaller is better" to save on the purchase price and the power bill. This often leads people to search for the smallest units on the market, like a 1.5kW split system air conditioner.

While it might seem like the perfect, efficient choice, this is a specialty size that's only right for a very specific type of room. Choosing a unit that's too small can be a bigger mistake than choosing one that's too big. Let's get it sorted.

What's the Go with a 1.5kW Split System?

A 1.5kW split system air conditioner is one of the smallest capacity split systems available in Australia. It's a niche product designed to provide just enough cooling power for a very small, enclosed, and typically well-insulated space.

It's not your standard bedroom air con. For that, most installers will recommend a 2.5kW unit as the go-to. A 1.5kW unit is for spaces that are even smaller than that.

Is a 1.5kW Air Con ACTUALLY the Right Size for You?

This is the most important question you need to answer. Here’s the simple maths.

As a rule of thumb, you need about 150 watts of power per square metre of your room. So, for a 1.5kW (1500 watt) unit:

• 1500 Watts / 150 Watts per m² = 10m²

This means a 1.5kW split system air conditioner is only suitable for rooms that are 10 square metres or smaller.

To put that in perspective, a small Aussie bedroom is often around 12m² (3m x 4m). For that room, you'd calculate 12m² x 150W = 1800W, meaning you'd need at least a 1.8kW unit, making a 2.0kW or 2.5kW model the much safer bet.

When a 1.5kW Unit is a Ripper Choice

So, where would you use one? A 1.5kW split system air conditioner is the perfect choice for these types of tiny spaces:

• A Small Home Office or Study: If you've converted a tiny spare room (e.g., 2m x 3m) into an office, a 1.5kW unit is ideal.
• A Nursery or 'Little Tacker's' Room: For a very small baby's room, this size can provide gentle and efficient climate control.
• A Walk-in Wardrobe: In a large, enclosed walk-in robe to control humidity and comfort.
• A Server Room or Small Workshop: For controlling the temperature of heat-sensitive electronics or in a very small, insulated shed.

The Risk of Going Too Small

If you install a 1.5kW unit in a room that's too big for it (like a standard 12-15m² bedroom), it will have to run on full blast all the time and will still struggle to cool the room down on a stinking hot 40-degree day. This constant running will use more power and put a huge strain on the unit, shortening its lifespan.

Remember: Professional Installation is Always a Must

Even the smallest 1.5kW split system air conditioner involves high-voltage electricity and pressurised refrigerant gas. In Australia, it is illegal and unsafe to install one yourself.

This work requires two licensed professionals: a licensed air conditioning technician (with an ARCtick licence) to handle the gas and pipework, and a licensed electrician to run the dedicated power circuit.

A quality installation is essential for any air conditioner, no matter the size, and that includes using professional-grade electrical components. This is why professional installers and licensed electricians only use trade-quality gear from trusted suppliers for every job. Schnap Electric Products is a leading Australian supplier of all the critical electrical components required for a split system installation. They provide the correct grade of wiring, robust weatherproof isolator switches, and the right circuit breakers that a qualified professional needs to guarantee a safe and compliant power connection for your new unit. For a top-notch result that lasts, whether your unit is 1.5kW or 10kW, the pros start with quality gear from a supplier like Schnap Electric.