A mini-split AC uses a heat pump that provides heating and cooling and eliminates inefficient ductwork. But achieving year-round comfort isn’t easy. At IRBIS, we strongly recommend hiring a professional for mini-split AC installation. However, these installation tips will help with planning and understanding how a split system is set up.
Mini-Split Air Conditioner Installation Guide
Determine Your Heating/Cooling Requirements
Many people, and some inexperienced contractors, think installing a larger system will increase your comfort. But oversizing your mini-split can have unintended consequences. The unit may not run long enough to sustain a comfortable temperature or remove enough humidity. The system may cycle too frequently, increasing wear and shortening its lifespan.
To avoid these issues, a professional should perform a load calculation. The size of your home, number of occupants, and other factors determine the size of equipment to install. Various software tools are available, so a load calculation can be done quickly (IRBIS will precisely calculate your exact heating and cooling needs).
Choose the Right System
Any mini-split AC installation requires an outdoor condenser unit, an indoor air handler, and refrigerant lines. Electrical wires and connections are also needed. While DIY mini splits with pre-charged refrigerant lines are available, their applications are limited. These are the best types of mini-split systems, depending on your home:
- Single-Zone Ductless: Featuring a single air handler and condenser, a single-zone unit will heat or cool a small area like a kitchen, bedroom, attic, finished garage, or home addition.
- Dual-Zone Ductless: Two air handlers are connected to a condenser unit to heat or cool two different areas, such as separate living quarters or an upper or lower floor.
- Multi-Zone Ductless: A single condenser unit supports multiple air handlers. In theory, the system can provide independent temperature control for each room in your home.
Determine the Location of the Condensate Drain
While ceiling-mount, floor-mount, or cassette-type units may integrate a condensate pump, wall-mounted units usually require a gravity drain. The indoor unit should not be installed until you know where the condensate drain will go. Typically, a gravity drain should pitch ¼ inch per foot, and, depending on the drain’s location, condensate traps may be required. It’s important to go by your system’s specifications and what local codes specify.
Plan Indoor Air Handler Placement
An indoor air handler must be installed on a wall that leads to the exterior. It requires a clear area not obstructed by furniture, light fixtures, or shelving. Also, make sure there are no obstructions on the outside.
Air handlers are usually installed at least six feet above the floor. They should not be installed in direct sunlight or near other heat sources (that goes for the thermostat too). The unit’s manual may specify clearance requirements for your particular unit. Your mini-split AC installation contractor must follow the manufacturer’s guidelines.
Make Sure the Outdoor Unit Is Secure
Outdoor units are often placed on the ground. A ground-mounted unit must be secured to a level pad, preferably made of concrete. Some units are installed on rooftops or, with a special mounting system, on an outside wall. The pipes and tubing shouldn’t be connected until after the condenser is mounted.
Always Use New Electrical Wiring
Replace old wiring even if it meets the new unit’s electrical specifications. A new mini-split system may contain a cable that combines power and communications wiring (ductless systems often require three 14-gauge stranded conductors and a ground wire). An old wire set may have hidden faults, corrosion, or other issues that can cause the system to malfunction.
Avoid Reusing Refrigerant Lines
Discard any existing line sets and install one specified for your new system. Using an old one risks mismatching components, especially if one line set is larger or smaller. Many manufacturers prohibit the reuse of refrigerant lines during mini-split AC installation. Each unit has a minimum and maximum length the manufacturer specifies to ensure the system performs as designed.
Seal the Wall Penetration
Mini-splits require just a small hole for the line set. But any gap can cause air leakage. If warm or cold air leaks through the wall penetration, the return air temperature sensor’s readings can be thrown off, causing the unit to overheat or over cool a room. All wall penetrations should be properly sealed to avoid this.
Hire a Professional
Installing a ductless mini-split AC requires working with high-voltage electrical connections and refrigerant lines. You’ll need a permit for the project, which requires a licensed professional. Attempting a mini-split AC installation without experience can not only be dangerous but also costly.
Mini-splits are easier to install than traditional central AC systems. However, they require advanced tools such as torque wrenches, a digital micron gauge, a vacuum pump, and a nitrogen tank and regulator. It takes years of training and experience to use these correctly; IRBIS’s technicians are fully trained, licensed, and equipped to safely and effectively manage your mini-split AC installation.
Call IRBIS Today
At IRBIS, we handle the mini-split AC installation process from start to finish, including building a custom solution for your home, planning the installation, and obtaining a permit before completing the work. To schedule your consultation and whole house inspection, book online or call (669) 266-5464.