How to Install a Mini Split System

New England winters are notorious for their biting cold and relentless snowfall. While the picturesque landscapes are a sight to behold, the frigid temperatures pose a significant challenge for homeowners, especially when it comes to heating separate structures like studios or workshops. At House Calls, we faced this exact dilemma. Our filming studio, detached from the main house, lacked an efficient heating and cooling system. Traditional methods like space heaters and old air conditioners were neither effective nor energy-efficient. The solution? Installing a mini-split system.

With the help of our friends at Fairfield County Heating and Cooling, we installed a mini-split system to help control our climate in the studio. 

What is a Mini Split System?

A mini-split system is a ductless heating and cooling solution that uses an outdoor compressor/condenser unit connected to one or more indoor air handlers via refrigerant lines. It provides zoned temperature control, offering energy efficiency and flexible installation compared to traditional ducted systems.

Why Choose a Mini Split System?

Before diving into the installation process, you might be wondering why a mini-split system is an excellent choice for heating and cooling, especially in climates like New England. 

Mini-split systems are recognized for their high energy efficiency, which leads to reduced energy consumption when compared to traditional HVAC systems. 

They offer zoned heating and cooling, enabling targeted temperature control in specific areas for optimal comfort where you need it most

Installation is less invasive and often faster than traditional systems since ductwork is not required, although professional installation is strongly advised. 

Furthermore, this system provides versatile year-round climate control by offering both heating and cooling capabilities in a single unit.

Consider your square footage and your climate when making the decision whether the mini split is right for you. 

Understanding the Mini Split System

A mini-split system offers ductless heating and cooling with an indoor wall unit that circulates conditioned air. This indoor unit is connected by refrigerant lines to an outdoor condenser unit. These systems provide zoned temperature control, making them efficient and flexible. The indoor unit (Evaporator) is typically mounted on the wall inside the space, it distributes warm or cool air throughout the room. The outdoor Unit (Condenser): Installed outside the building, it connects to the indoor unit via refrigerant lines.

Mike from Fairfield County Heating and Cooling explains, "A mini split is an air-to-air heat pump capable of both heating and air conditioning within the same unit. It's an efficient solution to replace old air conditioners and space heaters."

Is Installing a Mini Split a DIY Project?

Installing a mini-split system involves crucial considerations beyond simple setup: local regulations may mandate licensed HVAC professionals, electrical work often demands a dedicated 240-volt circuit requiring a licensed electrician, and properly charging the system with refrigerant must adhere to EPA regulations.

Mike's Recommendation: "I recommend hiring a licensed electrician and HVAC contractor to ensure the system is installed correctly and safely."

Preparing for Installation

Start by assessing your space by calculating the square footage you need to heat and cool and consider your local climate. A general guideline for sizing the unit is 35 BTUs per square foot, so a 500-square-foot space would require approximately 17,500 BTUs. Then, when selecting the right mini-split system, prioritize heating capacity suitable for low outdoor temperatures, look for high SEER and HSPF energy efficiency ratings, and consider features like programmable timers, remote controls, and multiple fan speeds.

Step-by-Step Mini-Split Installation Guide

Step 1: Choosing the Indoor Unit Location

Ideal Placement:

• Above Eye Level: Typically mounted high on a wall for optimal air distribution.
• Clear Airflow: At least 6 inches of clearance above and around the unit.
• Structural Support: The wall must be strong enough to hold the unit securely.

Our Choice:

We selected a spot above the window. Mike explains, "Placing it here allows the unit to circulate properly, drawing in hot air from the top and dispersing cool air from the bottom. In winter, it operates in reverse."

Step 2: Mounting the Bracket

Materials Needed:

• Mounting bracket (included with the unit)
• Level
• Screws and anchors suitable for your wall type

To attach the bracket:

1. Mark the Position: Use a level to mark where the bracket will be installed.
2. Secure the Bracket: Attach the bracket firmly to the wall. In our studio, the wood paneling provided sufficient support without needing to locate studs.
3. Ensure Levelness: Double-check that the bracket is level to prevent drainage issues.

Step 3: Drilling the Access Hole

To run the refrigerant lines, electrical wires, and drain hose from the indoor unit to the outdoor unit.

To drill an access hole:

1. Mark the Hole Location: Typically behind the indoor unit, as indicated by the installation template.
2. Drill a Pilot Hole: From inside, drill a small hole through to the outside to confirm placement.
3. Drill the Main Hole:
   • Use a hole saw (usually 3 to 4 inches in diameter).
   • Drill halfway from the inside, then complete from the outside to prevent damage to exterior siding.
   • Ensure the hole slopes slightly downward toward the outside for proper drainage.

Step 4: Installing the Indoor Unit

1. Prepare the Lines: Gently bend the refrigerant lines and drain hose to feed through the hole.
2. Feed the Lines: Push the lines and hose through the hole to the outside.
3. Mount the Unit: Hang the indoor unit on the bracket, ensuring it's secure and level.

Step 5: Electrical Connections

Important: Electrical work should be performed by a licensed electrician.

Step 6: Installing the Outdoor Unit

Proper placement of a mini-splits outdoor unit requires a stable foundation such as a concrete pad or stand, ample space for airflow and servicing, and, particularly in areas with snowfall, elevation to avoid snow accumulation and facilitate drainage during defrost cycles.

Our Installation:

Mike assembled a stand using pressure-treated lumber and exterior screws. "This keeps the unit off the ground, which is crucial during winter defrost cycles," he explains.

Step 7: Connecting Refrigerant Lines and Drain Hose

To connect, carefully run the refrigerant lines straight from the indoor to the outdoor unit, protecting them with PVC line covers or conduit, securely connecting the lines and electrical components to the outdoor unit according to the manufacturer's instructions, and installing a drain hose with a consistent downward slope for proper condensate drainage.

Step 8: Vacuuming and Charging the System

Note: This step should be performed by a certified HVAC technician.

Testing the Mini Split System

With everything connected and the system charged, it's time to test. First, turn on the electrical circuit and start the unit using the remote control. Then, set the desired temperature. We set it to the highest setting, known as "turbo," to quickly heat the space. Observe performance and feel the warm air distribution, check for consistent airflow, pay attention to the noise level, and that it running smoothly without excessive vibrations. 

Our studio transformed from a chilly space to a warm, comfortable environment!

Installing a mini-split system resulted in improved comfort through consistent heating, and increased efficiency by replacing older, less effective appliances.

Maintenance Tips

To keep your mini split system running efficiently:

• Regular Cleaning: Clean or replace filters every few months.
• Inspect Outdoor Unit: Keep the area around the outdoor unit free from debris and snow accumulation.
• Professional Servicing: Schedule annual maintenance checks with a licensed HVAC technician.

Embrace Year-Round Comfort with a Mini Split System

Installing a mini-split system revolutionized our studio's comfort level, making it a welcoming space regardless of the season. For homeowners facing similar challenges—whether it's a detached studio, garage, or a room without adequate heating and cooling—a mini split offers an efficient and effective solution.

Before choosing a mini-split system, it's essential to thoroughly understand your space's specific heating and cooling needs. While DIY installation might seem appealing, engaging professionals is highly recommended to ensure safety and optimal performance. In the long run, investing in a mini-split system offers not only immediate comfort but also potential energy savings and an increase in your property's overall value.

Additional Notes

Always consult the manufacturer's installation manual for your specific mini-split unit. Before installation, it's essential to check with your local municipality for any necessary permits and installation requirements. Additionally, investigate potential energy rebates or incentives available for installing energy-efficient systems.

Ready to Transform Your Space?

With a mini-split system, you can achieve year-round comfort efficiently and effectively. Whether you're in the heart of New England's winters or facing hot summers, this solution adapts to your needs. Your journey to a more comfortable living or working space starts with the right information and the right partners.