Top 7 Mistakes to Avoid During Air Conditioner Installation 

Last Updated on October 22, 2025

When it comes to keeping your home cool and comfortable in Brisbane’s heat, nothing beats a proper air conditioner installation. Many homeowners invest in quality systems but overlook one important part – the installation process. Even the best air conditioner won’t perform well if it’s not installed correctly. At Dawson Electric, we’ve seen how simple mistakes can lead to higher bills, poor performance, and costly repairs later on. 

Below, we’ve listed the seven most common mistakes people make when installing their air conditioning units and how our professional team can help you avoid them. 

1. Choosing the Wrong Size Unit 

The first mistake is selecting an air conditioner that’s too small or too large for your room. Many people guess the size without understanding that room size, insulation, and ceiling height all play a role. 

A unit that’s too small will struggle to cool the space, running non-stop and using more energy. On the other hand, an oversized system cools the room too quickly without removing humidity, making the air feel clammy. 

At Dawson Electric, we calculate the right capacity for your home using precise measurements. We match your room size with the correct kilowatt output, ensuring your system runs efficiently and keeps you comfortable all year round. 

2. Poor Placement of the Indoor Unit 

Where you install the indoor unit matters more than most people think. Placing it near a corner, above a doorway, or opposite a window can cause uneven airflow. The cool air might not reach every part of the room, leaving hot and cold spots. 

Our licensed technicians always check airflow direction and room layout before installing. We position the indoor unit so the air circulates evenly, giving you consistent cooling throughout your space. 

Proper placement also helps avoid excess condensation on walls and furniture, keeping your home dry and clean. 

3. Ignoring Electrical Requirements 

An air conditioner draws a significant amount of power. Using the wrong circuit or skipping a dedicated power line can overload your home’s electrical system. Unfortunately, many DIY installers or unqualified handymen overlook this crucial step. 

Every air conditioning installation we perform follows strict electrical safety standards. Dawson Electric is a fully licensed electrical contractor, so we handle both your electrical wiring and your air conditioning setup in one visit. You’ll receive a certificate of compliance that ensures your system meets Queensland’s legal standards. 

4. Skipping Proper Insulation and Sealing 

Another big mistake is not checking the insulation and sealing in the room before installation. Without good insulation, cool air leaks out, forcing your unit to work harder. The result is higher energy bills and faster wear on your system. 

Our team inspects the walls, ceiling, and windows before installation. We recommend affordable insulation upgrades or sealing gaps if needed. This step helps your new air conditioner perform at its best while reducing your electricity costs over time. 

5. Poor Outdoor Unit Placement 

The outdoor condenser unit is often overlooked. Many people install it in a tight corner, under direct sunlight, or near a wall without enough airflow. This limits efficiency and shortens the life of your system. 

We always place the outdoor unit where it can “breathe.” That means enough clearance for air to flow freely and less exposure to harsh weather. We also ensure it’s mounted securely to prevent vibration or noise transfer into your home. 

Quote of the day: 
“Cool comfort starts with smart installation — let Dawson Electric do it right the first time.” 

6. Neglecting Drainage and Water Flow 

Water dripping from an air conditioner is not normal. It often means the drain line wasn’t installed properly. Poor drainage can cause mold, wall damage, and unpleasant odours. 

Our technicians make sure the condensate drain line is angled correctly and securely fitted. We also test the system before leaving your property to confirm that water flows away safely. This small step prevents big problems later on. 

7. Not Hiring a Licensed Installer 

The biggest mistake of all is trying to install the system yourself or hiring someone without the proper licence. In Queensland, it’s illegal for an unlicensed person to install split systems. It can also void your manufacturer’s warranty. 

At Dawson Electric, all our installers are fully qualified and insured. We follow all manufacturer guidelines, ensuring your warranty remains valid. You’ll get peace of mind knowing your system was installed safely, efficiently, and correctly. 

We also handle the entire process for you — from supply to installation and testing. Our experienced team works neatly, respects your home, and provides friendly service every step of the way. 

Why Professional Installation Matters 

Professional installation doesn’t just protect your system it saves you money. When your air conditioner is installed correctly, it uses less energy, lasts longer, and performs better. 

Many customers who switch to Dawson Electric after poor installations notice immediate improvements. Their systems cool faster, run quieter, and don’t need as much maintenance. 

We also provide expert advice on selecting energy-efficient models, ideal placement, and long-term care tips. When you choose us, you’re not just getting an installer — you’re getting a local team that values honesty, safety, and customer satisfaction. 

Maintenance Tips After Installation 

To get the best out of your air conditioner, regular care is key. Here are a few easy tips: 

• Clean the filters every few weeks during summer 

• Check the outdoor unit for dust and leaves 

• Schedule a professional service at least once a year 

• Keep doors and windows closed while cooling 

• Avoid setting temperatures too low (24°C is ideal for comfort and efficiency) 

Dawson Electric also offers ongoing maintenance plans for Brisbane homeowners. These visits help keep your unit running smoothly, prevent breakdowns, and extend its lifespan. 

Trust the Experts at Dawson Electric 

Avoiding these seven mistakes can make a big difference in comfort, safety, and energy savings. The team at Dawson Electric has helped hundreds of Brisbane homeowners enjoy reliable cooling with professional installations done right. 

We provide transparent pricing, fast quotes, and guaranteed workmanship. Whether you need a new system or want to replace an old one, we’re here to make the process easy and stress-free. 

If you want your next air conditioner installation to be smooth, efficient, and done by qualified experts, contact Dawson Electric today. 

FAQs 

1. How long does it take to install a new air conditioner? 
Most split system installations take between 3 to 6 hours, depending on the layout and wiring. 

2. Do I need to supply the air conditioner myself? 
No, our team can supply and install quality brands like Daikin, Fujitsu, and Mitsubishi Electric. We’ll help you choose the right system for your space. 

3. Will you remove my old unit? 
Yes, we can safely disconnect and remove your old unit before installing the new one. 

4. Can I install my own air conditioner? 
No, only licensed professionals can legally install air conditioners in Queensland. Doing it yourself can void warranties and cause safety risks. 

5. Do you service areas outside Brisbane? 
Yes, we cover Brisbane and surrounding suburbs. Contact our friendly team to check service availability in your area.