7 Common Mistakes to Avoid When Installing a Ductless AC

Installing a ductless air conditioner (also called a mini-split system) is a great way to cool specific rooms or areas in your home. These systems are efficient, easy to install, and provide focused cooling. However, to get the best out of your ductless ac, you need to avoid some common mistakes. Here are seven mistakes people often make and how to avoid them.

1. Choosing the Wrong Size Unit: One common mistake is picking the wrong size unit for your room. A unit that’s too big will turn on and off too often, wasting energy and not cooling properly. A unit that’s too small will struggle to cool the room and might wear out faster. To avoid this, measure your room and check what size unit you need. It’s a good idea to ask a professional for help.

2. Bad Placement of the Outdoor Unit:The outdoor unit also needs a good spot. Don’t put it in a small, enclosed space where it can overheat. Make sure there’s enough space around it for air to move. Try to keep it out of direct sunlight and put it on a solid, level surface to reduce noise and vibrations.

3. Ignoring Electrical Needs : Ductless AC systems need specific electrical setups. Ignoring these needs can be dangerous and cause problems with the unit. Make sure the electrical circuit can handle the unit’s power and that the wiring is done right. It’s best to have a licensed electrician do this part.

4. Skipping the Vacuum Step: After connecting the refrigerant lines, you need to remove air and moisture from the system using a vacuum pump. Skipping this step can make the system less efficient and might damage it. This step makes sure the refrigerant flows correctly. It’s a technical task, so you might want a professional to do it.

5. Incorrect Drainage Setup: Ductless AC units produce water that needs to drain away properly. If the drainage is set up wrong, it can cause leaks and water damage. Make sure the drain pipe slopes downward so water can flow out. Some systems have a pump for this, which needs to be installed correctly. Our installation team can ensure your drainage system is set up correctly to prevent any issues.

6. Neglecting Regular Maintenance: After installation, regular maintenance keeps your ductless AC running well. Forgetting to clean filters, check refrigerant levels, or inspect the system can reduce its efficiency and lead to costly repairs. Set a schedule for maintenance and stick to it. You can also sign up for a professional maintenance plan. Set a maintenance schedule and stick to it. Ventac offers maintenance plans to keep your system in top condition year-round.


A ductless ac system can cool your home efficiently if installed properly. By avoiding these common mistakes, you ensure your system works well and lasts a long time. Remember to choose the right size, place the units correctly, set up the electrical and drainage systems properly, and perform regular maintenance. If you’re unsure, hiring a professional can help you save time, money, and avoid headaches.