For U.S. homeowners seeking energy-efficient and cost-effective heating and cooling solutions, the MRCOOL DIY Mini Split system is an increasingly popular choice. Designed with user-friendly features and pre-charged refrigerant lines, this ductless system allows for a DIY installation that minimizes the need for professional HVAC technicians. This article provides a detailed, step-by-step guide to the installation process, along with essential accessories, safety considerations, and maintenance tips based on the documentation provided by MRCOOL.
Introduction
MRCOOL Mini Split systems are designed for versatility, quiet operation, and energy efficiency. They are ideal for use in a variety of spaces, including bedrooms, offices, garages, and additions. The installation process is structured to be accessible to individuals with basic DIY skills, though certain aspects—particularly electrical work—may require professional assistance.
This guide is based on official installation instructions and product descriptions from MRCOOL’s resources. It covers the planning phase, necessary tools and materials, installation of both indoor and outdoor units, electrical and refrigerant line connections, and post-installation testing. Additionally, it highlights recommended accessories to enhance performance and aesthetics.
Planning & Preparation
Choosing the Right MRCOOL Mini Split Model
Before purchasing a MRCOOL Mini Split, it is essential to determine the appropriate British Thermal Unit (BTU) rating for the intended space. The BTU rating determines the system’s cooling and heating capacity. The following guidelines are provided:
- Small Rooms (150–350 sq. ft.): 9,000–12,000 BTU
- Medium Rooms (350–600 sq. ft.): 18,000 BTU
- Large Rooms (600–1,000 sq. ft.): 24,000 BTU
- Extra-Large Spaces (1,000+ sq. ft.): 36,000 BTU+
A unit that is too small will struggle to maintain a comfortable temperature, while an oversized unit may cycle on and off frequently, reducing efficiency and increasing wear.
Tools & Materials Needed
To successfully install a MRCOOL Mini Split, gather the following tools and materials:
- Drill and drill bits for wall installation
- Level to ensure the unit is mounted correctly
- Screwdrivers (Phillips and flathead)
- Tape measure
- Crescent wrenches (2x) for refrigerant line connections
- Allen wrench for opening refrigerant valves
- Wall anchors and screws
- Electrical supplies, including correct wire gauge and disconnect box based on the unit’s specifications
It is also recommended to have a voltage tester and multimeter for electrical work. Safety equipment such as gloves and goggles should be worn during the installation process.
Check Local Codes & Regulations
Before beginning the installation, it is essential to review local building and electrical codes. Some jurisdictions may require a permit for electrical work. Compliance with these regulations ensures that the installation is safe and avoids potential issues during future home inspections or property sales.
While MRCOOL Mini Splits are designed for DIY installation, certain electrical wiring steps may require the assistance of a licensed electrician. Failure to adhere to local codes can result in safety hazards or voided warranties.
Installation Process
Indoor Unit Installation
Step 1: Choosing the Right Wall Location
The indoor unit should be placed in a location that ensures proper airflow and optimal temperature distribution. Key considerations include:
- Avoid areas with direct sunlight or heat sources such as ovens or heaters.
- Ensure at least 6 inches of clearance from the ceiling and 12 inches from side walls.
- The unit should be positioned near the outdoor unit to facilitate refrigerant line routing.
- The unit should be centrally located in the room for even air distribution.
Step 2: Mounting the Indoor Unit
Once the location is selected, the unit is mounted using wall anchors and screws. A level is used to ensure the unit is mounted correctly. The mounting bracket should be securely fastened to prevent vibration and ensure long-term stability.
Step 3: Connecting Refrigerant Lines
The refrigerant lines are routed from the indoor unit to the outdoor unit. A 3 1/2-inch hole saw is used to create an opening in the wall for the lines. The lines should be secured and insulated to prevent heat loss or gain. A torque wrench is used to tighten all connections, and a soap and water solution can be applied to detect leaks. If bubbles appear, the connections should be tightened and retested.
Outdoor Unit Installation
Step 1: Choosing the Location
The outdoor unit should be placed on a flat, stable surface that allows for proper air circulation and ventilation. The following guidelines are recommended:
- Avoid busy streets, crowded areas, and sources of combustible gas.
- The unit should be protected from excessive dust, salt air, or areas prone to forced water exposure.
- Ensure the unit is shielded from prolonged sun exposure and rain.
- In snowy areas, steps should be taken to prevent ice buildup and coil damage.
- Clearance requirements include:
- 24 inches above
- 79 inches in front
- 12 inches on the left side
- 24 inches on the right side
- 12 inches (ground-mounted) or 6 inches (bracket-mounted) from the wall
Step 2: Connecting to the Indoor Unit
Refrigerant lines from the indoor unit are connected to the outdoor unit. All connections should be made using a torque wrench to ensure they are secure and leak-free. The lines should be insulated and protected from environmental factors.
Step 3: Electrical Considerations
The electrical connections should be made according to the MRCOOL installation manual. A voltage tester should be used to verify the connections and ensure they are safe. Proper grounding is essential to prevent electrical hazards.
Step 4: Install the Sound Deadening Pads
To minimize noise transmission and vibration, sound deadening pads should be installed between the outdoor unit and its mounting surface. This step is especially important if the unit is mounted near living spaces.
Recommended Accessories
MRCOOL Line Set Cover Kit
The Line Set Cover Kit ($137) is recommended to protect the refrigerant lines from environmental damage, UV rays, and potential harm from animals. It also helps to insulate the lines, maintaining system efficiency. The cover should be fitted without pinching the lines and should allow for easy maintenance.
MRCOOL Condenser Wall Bracket
The Condenser Wall Bracket ($127) is used to elevate the outdoor condenser unit, protecting it from dirt, snow, and debris. This bracket extends the unit’s lifespan and reduces vibration and noise transmission. The bracket should be mounted on a stable, sturdy wall at the correct height to ensure optimal airflow.
MRCOOL Mini-Stat Smart App Controller
The Mini-Stat Smart App Controller ($168) provides remote control via a smartphone app, allowing users to adjust temperatures, set schedules, and monitor system performance. It enhances energy management and convenience. The controller should be placed within a good range of the Wi-Fi router for stable connectivity.
Safety Considerations
When DIY Is Not Recommended
If there are any uncertainties regarding electrical connections, it is advisable to hire a licensed professional. HVAC systems involve high-voltage electricity, and improper handling can pose serious safety risks. Professional installation also ensures compliance with building codes and maintains the warranty.
Electrical Safety
Electrical work should be performed with caution. Always turn off the power at the main panel before beginning any electrical connections. Use a voltage tester to confirm that the power is off. Ensure that all wiring is done according to the manufacturer’s specifications and local codes.
Post-Installation Testing
Powering Up the System
Once the installation is complete, power is restored at the electrical panel. The system is turned on using the remote control or the MRCOOL SmartHVAC app. Both heating and cooling modes should be tested to ensure proper operation.
Testing for Leaks
Refrigerant leaks can impact system performance and efficiency. A soap and water solution can be used to check for bubbles at the refrigerant line connections. If leaks are detected, the connections should be tightened and retested.
Smart Home Integration
The MRCOOL Mini Split can be integrated with smart home platforms such as Google Home and Alexa. This allows for voice-controlled climate adjustments and automated temperature scheduling, which can reduce energy use and maximize efficiency.
Maintenance and Long-Term Care
Regular Cleaning and Inspection
To maintain optimal performance, the indoor and outdoor units should be cleaned and inspected regularly. Dust and debris can accumulate on the coils and affect efficiency. It is also important to check for any signs of wear, such as loose connections or unusual noises.
Seasonal Checks
During seasonal transitions, it is recommended to test the system in both heating and cooling modes. This ensures that the unit is functioning correctly and efficiently. Any issues should be addressed promptly to prevent further damage.
Conclusion
The installation of a MRCOOL Mini Split system is a practical and cost-effective solution for heating and cooling various spaces in the home. With the right tools, careful planning, and adherence to safety guidelines, most homeowners can successfully complete the installation as a DIY project. The ductless design, energy efficiency, and smart home integration make this system a valuable addition to modern homes.
By following the step-by-step process outlined in this guide, users can ensure a safe, efficient, and long-lasting installation. Whether you are upgrading an existing system or installing a new one, the MRCOOL Mini Split offers a reliable and user-friendly option for improving home comfort.