What Is a Ducted Split System?
A ducted split system is an HVAC system composed of two main components: the outdoor unit and the indoor unit. The outdoor unit is typically installed outside the building and contains the compressor, condenser, and fan. The indoor unit, installed inside the building, includes the evaporator and a fan. These two units are connected by copper refrigerant pipes.

History of Ducted Split Systems

Modern HVAC systems have evolved from earlier technologies. The first air conditioning systems appeared in the late 19th and early 20th centuries. In 1902, Willis Haviland Carrier invented the first mechanical air conditioning system, earning him the title “father of modern air conditioning.” Early systems were large and expensive, used only in big buildings like hotels and hospitals.

In the 1950s, smaller, more affordable systems became available for residential use. Initially, single-unit systems were common. By the 1960s, split systems with separate indoor and outdoor units appeared. Eventually, ducted split systems were introduced, offering more flexibility and easier installation.

During the 1970s and 1980s, ducted split systems gained widespread use. Inverter technology was developed, enabling compressors to adjust their speed for better energy efficiency.

Today, ducted split systems are widely used for their efficiency, flexibility, quiet operation, and advanced features such as temperature, humidity, and air quality control.

Advantages of Ducted Split Systems

• Comfort & High Efficiency: Provides uniform heating/cooling for large spaces with precise temperature and humidity control.
• Design Variety: Available in various designs to match interior aesthetics.
• Easy Installation: Requires fewer structural changes compared to older systems.
• High Energy Efficiency: Advanced technologies help reduce power consumption.
• Quiet Operation: Quieter than older HVAC systems.
• Zoned Temperature Control: Allows independent temperature settings for different rooms.
• Long Lifespan: Generally offers easy maintenance and long service life.

Standard vs. Inverter Ducted Split Systems

• Standard Ducted Split: Fixed-speed compressor, lower efficiency, higher energy use.
• Inverter Ducted Split: Variable-speed compressor, better efficiency, quieter, and more energy-saving (up to 30% less energy consumption).
  Despite a higher initial cost, inverter models save significantly on electricity bills over time.

Ducted Split Capacities

Available in various capacities, ranging from 9,000 to 60,000 BTU/hr, chosen based on:

• Area size
• Ceiling height
• Sunlight exposure
• Number of occupants

How to Choose a Ducted Split System

1. Load Calculation: Assess heating/cooling needs based on room size, orientation, climate, and occupancy.
2. Select Capacity: Based on thermal load calculations.
3. Choose Compressor Type:
   • Inverter: Energy-saving, precise control
   • Fixed Speed: Lower upfront cost
4. Duct Design: Ensure effective air distribution and low resistance airflow.

Ducting Options

• Galvanized Steel: Durable and corrosion-resistant, but heavy and costly.
• Spiral Duct: Flexible and easy to install.
• Flexible Duct (Flex Duct): Ideal for tight spaces but limited to short runs (~5 meters).
• Polyurethane Duct: Lightweight, fire-resistant, thermally insulated, affordable, but prone to breakage on impact.

Drain Pipe Installation

• Location: Drains from the indoor unit must lead safely outside the building.
• Path: Should be short, sloped, and without sharp angles.
• Material: Commonly PVC or polyethylene with a minimum 3/4 inch diameter.
  Proper installation prevents leakage and building damage.

Outdoor Unit Placement

• Install close to the indoor unit with minimum pipe length.
• Protect from direct sun, rain, and snow to improve longevity and efficiency.

Indoor Unit Placement

• Should allow optimal air distribution.
• Ensure clearance from walls and ceiling for airflow.
• Must be accessible for maintenance and service.

Maximum Piping Lengths

• Horizontal Run: Typically up to 50 meters.
• Vertical Rise: Between 10–15 meters, depending on brand and model.

When to Use a Ducted Split System

Ideal for large commercial, office, or retail spaces.

• Can provide heating via hot water coils.
• One unit can replace multiple split units, saving energy and preserving interior design.

Compressor Types by Power Supply

• Single-Phase Compressors: 220V, used in homes and small businesses.
• Three-Phase Compressors: 380V, for larger commercial and industrial setups.

Compressor Types by Mechanism

• Piston (Reciprocating): Simple, serviceable, but noisy and less efficient.
• Rotary: Quiet, compact, and efficient—common in homes and small businesses.
• Scroll: Quiet, durable, and highly efficient—used in large and advanced systems.

Compressor Types by Energy Use

• Fixed Speed: One-speed operation, high energy use, simple and cheap.
• Inverter: Variable-speed operation, energy-efficient, stable temperature control, quieter, but higher initial cost.

Main Differences: Ducted Split vs. Wall-Mounted Split

• Pipe Length: Ducted split allows longer piping.
• Air Distribution: Ducted systems use ducts, while wall units blow directly.
• Coverage: Ducted splits handle larger areas; wall splits are for smaller rooms.

Conclusion

Ducted split systems are one of the most widely used HVAC solutions today. They offer flexibility, energy efficiency, and advanced features like precise temperature control, humidity management, and air filtration.

Avash Sepidar Sepehr Company offers four major ducted split brands: Midea, Lenzor, LG, and G Plus—all featuring inverter technology for reduced energy consumption.

Ducted Split Brands Offered by Avash Sepidar Sepehr

• Lenzor: Low-noise, low-consumption systems from China.
• Midea: Stylish and high-performance, with smart controls and inverter tech.
• LG: High-quality Korean brand with tropical compressors for diverse climates.
• G Plus: High-capacity systems with single-phase operation and full warranty.

Company Services

Avash Sepidar Sepehr provides:

• Monthly maintenance and inspection
• Free service for 36 months
• Expert technicians for installation and support

For more info or to get a quote, contact the company directly through their website or phone.