Air Handling Unit (AHU), or simply AHU, is an essential device in air conditioning and refrigeration systems. This unit is used to process and supply conditioned air for indoor spaces.
The primary function of an AHU is to filter, heat or cool, and supply fresh airflow to the indoor environment. An AHU usually consists of several parts and different systems, which include:
Filters: The AHU is equipped with fresh air filters that remove suspended particles, pollutants, bacteria, and contaminants from the air. These filters are used to improve the quality of the supplied air.
Heater and Cooler: The AHU is equipped with heating and cooling coils used to regulate air temperature. In cold seasons, the heater is activated, and in hot seasons, the cooler operates.
Control Panel: The AHU has a control system designed to manage its performance and different parameters. This panel typically includes sensors, controllers, and a display screen.
Fan: The AHU contains fan(s) that create airflow through the air handling unit.
AHUs are widely used in air conditioning systems, HVAC systems (Heating, Ventilation, and Air Conditioning), industrial buildings, hospitals, offices, hotels, and other places where fresh air is needed. They are typically employed in larger HVAC systems to provide fresh air, ventilation, and environmental conditioning.
Schematic Diagram of a Constant Volume Air Handling Unit
A schematic diagram of a Constant Volume Air Handling Unit usually includes the following components:
Air Inlet: To bring in fresh air from outside
Filters: To remove suspended particles and pollutants
Cooling and Heating Coils: To regulate temperature
Fan: To move the air
Air Outlet: To distribute conditioned air into the space
Types of AHU Filters
Air Handling Unit filters are responsible for removing suspended particles from the air to ensure the supplied air is clean for the space being ventilated. Different types of filters are available for AHUs, each designed to remove particles of specific sizes and characteristics. Common types include:
Particulate Filters: Designed to remove airborne particles such as dust, minerals, organic matter, and more.
Gas Phase Filters: Used to eliminate gaseous pollutants such as odors, chemical gases, and other contaminants.
HEPA Filters (High Efficiency Particulate Air): Highly effective at removing extremely fine particles and microbes. These are widely used in sensitive environments such as operating rooms, laboratories, and clean rooms.
Antibacterial Filters: Designed to reduce airborne bacteria and prevent the transmission of airborne infections.
The choice of a suitable filter depends on the type of pollutants present in the environment and the air conditioning requirements of the space.
Types of Air Handling Units Based on Unit Configuration
Air Handling Units (AHUs) can be categorized into several types based on their physical layout. Some of the most common types are:
Horizontal Unit: In this type of AHU, the components are arranged in a horizontal plane. Air enters from one side and exits through the opposite side. These units are generally used in spaces with limited ceiling height.
Vertical Unit: In this type, the components are arranged vertically. Air flows either from top to bottom or bottom to top. This type is usually installed in spaces with higher ceilings.
Turbo Unit: This type resembles a solar fan with vertical stacks for air movement. These units are much smaller than horizontal or vertical ones and are used in smaller spaces or for specific needs.
Ceiling Unit: Installed within the ceiling, this type is designed to fit directly into ceiling structures, delivering airflow horizontally or vertically. It is often used in compact spaces or areas with high heat loads.
Window Unit: Mounted on windows, this type functions as a portable AHU. They are suitable for smaller and confined spaces, such as offices or bedrooms.
These are just a few examples of AHU types based on unit configuration. Each type may have its own unique features and applications, chosen depending on environmental and building requirements.
Types of AHUs Based on Airflow Direction
According to airflow direction, AHUs can be divided into three categories:
Horizontal Air Handlers: Air moves horizontally from the inlet to the outlet. These are typically floor-mounted and widely used in industrial and commercial spaces.
Vertical Air Handlers: Air moves vertically, either top-to-bottom or bottom-to-top. These are often installed in high-rise spaces such as tall buildings, towers, and large residential or commercial complexes.
Mixed Air Handlers: These units combine horizontal and vertical airflow simultaneously. They are typically used to enhance air handling capacity and distribute air in larger spaces.
It’s important to note that this classification is based on airflow direction, and some AHUs may incorporate multiple designs to allow multidirectional airflow. Each type has specific features and applications depending on environmental and structural needs.
Types of AHUs Based on Zoning
Single-Zone AHU: Used in spaces requiring uniform air conditioning.
Multi-Zone AHU: Designed for spaces with different ventilation requirements. Each zone can have its own specific temperature control.
Variable Air Volume (VAV) AHU: In this type, the air volume supplied to each zone can be adjusted according to demand.
Types of Air Handling Units Based on Size
Small AHU: Designed for small spaces such as offices and apartments.
Medium AHU: Suitable for medium-sized spaces such as large offices and retail stores.
Large AHU: Used for large and industrial spaces such as factories and hospitals.
Residential and Industrial AHUs
Air handling units are divided into two categories: residential and industrial, each with its own features and applications.
Residential AHUs:
These units are designed for household use, often serving as HVAC systems in homes. They are smaller in size and provide cooling and heating for small to medium spaces such as bedrooms, living rooms, kitchens, and other household areas. Some residential AHUs also include features such as air purification, humidification, and fresh air control.Industrial AHUs:
These are designed for industrial, commercial, and large environments. They are used in large buildings such as offices, hospitals, malls, factories, gyms, and public spaces. Industrial AHUs are usually larger in size and can process large volumes of air. They typically include components such as filters, heating and cooling coils, fans, and smart control systems.
Each category comes with its own features, capabilities, and limitations, and the choice depends on environmental and usage requirements.
Main Types of AHUs
1. Conventional AHUs
Fan Types: May include different types of fans depending on ventilation and HVAC requirements.
Humidity Control Equipment: Some models include humidification systems, while others do not.
Casing Material: Often made from corrosion-resistant materials such as galvanized steel or aluminum, with insulated structures.
Coil Types: Can include water coils (chilled water, hot water, or direct evaporative) or DX coils, depending on the heating/cooling needs.
2. Hygienic AHUs
Application: Used in environments where clean and sterile air is critical, such as hospitals, laboratories, and pharmaceutical industries.
Features: Equipped with high-efficiency filters (HEPA), disinfection systems, and precise humidity control. The casing is usually made from stainless steel or washable materials.
3. Heat Recovery AHUs
Application: Designed to recover thermal energy from exhaust air, reducing energy consumption and increasing efficiency.
Features: Include a heat exchanger that transfers heat from exhaust air to incoming fresh air. Commonly used in energy-intensive buildings for maximum efficiency.
Comparative Overview
Efficiency: Hygienic AHUs are ideal for sensitive environments; Heat Recovery AHUs are focused on energy optimization; Conventional AHUs have broader, general applications.
Cost: Hygienic AHUs are typically more expensive due to advanced components and technologies.
Maintenance: Hygienic AHUs require more frequent cleaning and special filters. Heat Recovery AHUs need regular care due to heat exchangers.
Types of AHUs Based on Air Distribution Zones
Single-Zone AHU
Function: Supplies fresh and conditioned air to a single zone. The entire area is ventilated through one unified system.
Application: Suitable for spaces with uniform ventilation needs, such as a large hall or open area.
Advantages: Easier to install and maintain, with lower costs compared to multi-zone systems.
Multi-Zone AHU
Function: Capable of conditioning and ventilating multiple zones with different requirements. Each zone can have independent temperature and airflow control.
Application: Ideal for large buildings, offices, hospitals, and hotels where various spaces require different climate conditions.
Advantages: Provides precise control of temperature and ventilation per zone, enhancing comfort and energy efficiency.
Variable Air Volume (VAV) Air Handling Units
Function: These AHUs adjust the airflow based on the needs of each zone. Airflow is varied to maintain the desired temperature in each area.
Application: Suitable for buildings with varying thermal loads, such as office buildings, universities, and commercial centers.
Advantages: Increased energy efficiency, more precise temperature control, and reduced operational costs.
Constant Air Volume (CAV) Air Handling Units
Function: In these AHUs, the airflow remains constant, and temperature control is achieved by adjusting the temperature of the supplied air.
Application: Ideal for spaces with constant thermal loads and fixed ventilation requirements, such as production halls and workshops.
Advantages: Simpler system with lower installation and maintenance costs compared to VAV systems.
General Comparison
Flexibility: Multi-zone and VAV AHUs provide greater flexibility in controlling temperature and ventilation across different zones.
Energy Efficiency: VAV systems are more energy-efficient due to their ability to adjust airflow according to demand.
Installation and Maintenance Costs: Single-zone and CAV AHUs have lower installation and maintenance costs but offer less flexibility and energy efficiency.
Application: The choice of AHU depends on the building type, the number of ventilation zones, and the ventilation and temperature requirements of each area.
AHU Brands Offered by Avash Sepidar Sepehr
Avash Sepidar Sepehr provides air handling units and HVAC equipment from four main brands:
Midea
Features: Midea is a reputable brand in HVAC equipment, known for high quality, energy efficiency, and advanced technology.
Products: Includes ducted split systems, gas coolers, and central air conditioning systems.
Lenzor
Features: Lenzor is recognized for producing high-quality and durable HVAC systems, designed for optimal performance and energy savings.
Products: Includes central air conditioning systems and various ducted split systems.
Trust
Features: Trust is known for reliability, high performance, and suitability for different environments. Their AHUs deliver consistent and dependable operation.
Products: Includes central air conditioning systems and various ducted split systems.
These brands are well-regarded in the HVAC market and are offered by Avash Sepidar Sepehr.
Services of Avash Sepidar Sepehr in HVAC Systems
Consulting
Avash Sepidar Sepehr provides expert consultation. Our team of specialists, with years of experience in the HVAC industry, helps clients select the most suitable air handling solutions based on environmental conditions and needs.
System Design
Our engineering and design team creates HVAC systems tailored to the specific requirements of each project, ensuring optimal compatibility with environmental conditions.
Sales
Avash Sepidar Sepehr offers reputable, high-quality AHU brands across Khuzestan Province, ensuring customers purchase reliable and durable products.
Installation
Installing an AHU requires precision and expertise. Our experienced installation team ensures that HVAC systems are installed optimally to maximize efficiency and lifespan. We are committed to high-quality installation to ensure customer satisfaction.
After-Sales Service
Avash Sepidar Sepehr provides 24-hour after-sales service throughout Khuzestan Province. Our support team is always ready to provide guidance, repairs, and periodic maintenance to ensure your HVAC systems operate at peak performance. With our after-sales service, peace of mind and high system efficiency are guaranteed.
