Skip to main content

Air Handling Unit (AHU) in HVAC system

 An Air Handling Unit (AHU) is a crucial component in HVAC systems, responsible for conditioning and circulating air in industrial, commercial, and residential settings. Here are some key details about AHUs:


- Definition: AHU is a self-contained unit that houses various components like fans, coils, filters, and controls to process and distribute air.


- Functions:

    - Heating, cooling, or ventilating air

    - Filtering and cleaning the air

    - Controlling humidity and temperature

    - Circulating air through ductwork


- Types:

    - Rooftop AHUs

    - Indoor AHUs

    - Modular AHUs

    - Custom-built AHUs


- Components:

    - Fans (supply, return, and exhaust)

    - Coils (heating, cooling, and heat recovery)

    - Filters (air, gas, and particulate)

    - Humidifiers and dehumidifiers

    - Controls and sensors


- Applications:

    - Commercial buildings

    - Industrial facilities

    - Hospitals and healthcare

    - Data centers and telecom

    - Large residential complexes


AHUs play a vital role in maintaining indoor air quality, thermal comfort, and energy efficiency. They come in various sizes and configurations to suit specific requirements.


Would you like to know more about AHUs or other HVAC topics? Just ask!

Comments

Popular posts from this blog

VALVES USED IN A CHILLER SYSTEM AND THE TYPICAL VALVE PACKAGE

  VALVES USED IN A CHILLER SYSTEM AND THE TYPICAL VALVE PACKAGE 1.Chilled Water Side Valves ⇒Isolation valve (manual/electric actuated). ⇒ Installed on CHW supply and return lines.  ⇒ Used to isolate chiller for maintenance. 2. Balancing Valve (Manual or Automatic)  ⇒ Ensures correct flow rate to/from chiller.  ⇒ Helps maintain Delta T and proper flow distribution.  ⇒ Located after evaporator outlet (return line). 3. Differential Pressure Bypass Valve (if 2-way valves in system)  ⇒ Prevents excess pressure build-up when terminals shut.  ⇒ Maintains flow through chiller. 4. Flow Switch  ⇒ Senses chilled water flow across evaporator.  ⇒ Safety interlock: trips chiller if flow is lost.  ⇒ Usually paddle type or electronic. 5. Air Vent Valve (Manual or Automatic)  ⇒ Removes air pockets.  ⇒ Placed at high points of piping and chiller headers. 6. Drain Valve  ⇒ For flushing, cleaning, and maintenance.  ⇒ Located at low poin...

HVAC MEP Thumb Rules & Formulas (With Examples)

  HVAC MEP Thumb Rules & Formulas (With Examples) 1. Heat Load Calculation  Formula: Q = Area (sq.ft) x Heat Load Factor (BTU/hr per sq.ft) Example: 500 sq.ft office: Q = 500 x 30 = 15,000 BTU/hr TR = 1.25 2. CFM Calculation Formula: CFM = Sensible Heat (BTU/hr) / (1.08 x Delta T) Example: 12,000 BTU/hr, Delta T = 20°F CFM = 556 3. AHU/FCU Sizing Rule: 1 TR = 400 CFM 2 TR Airflow = 800 CFM 4. Duct Sizing Velocity Limits: Main: 1400-1800 FPM 800 CFM @ 1000 FPM 0.8 sq.ft 14"x10" 5. Chilled Water Flow Rate Formula: GPM = BTU/hr / (500 x Delta T) Example: 24,000 BTU/hr GPM = 4.8 6. Pipe Sizing 1" pipe: 8-12 GPM 2" pipe: 30-40 GPM 35 GPM Use 2" 7. Chiller Sizing Formula: TR = BTU/hr / 12,000 Example: 60,000 BTU/hr → 5 TR 8. Cooling Tower Sizing Rule: Heat Rejection = 1.25 x Load 10 TR → Tower = 12.5 TR 9. Pump Head Calculation Formula: Power (kW) = (Q x H x 9.81) / (Efficiency x 1000) Example: Q = 5 L/s, H = 20 m, Efficiency = 0.75 Power 1.31 kW 10. Fresh Air Re...

Type of Heat Exchanger

 There are several types of heat exchangers used in HVAC systems, including: 1. Coil Type:     - Chilled water coils     - Hot water coils     - DX (direct expansion) coils     - Evaporator coils     - Condenser coils 2. Shell and Tube Type:     - U-tube heat exchangers     - Straight tube heat exchangers 3. Plate Type:     - Plate and frame heat exchangers     - Plate and shell heat exchangers 4. Finned Tube Type:     - Finned tube heat exchangers 5. Spiral Type:     - Spiral heat exchangers 6. Regenerative Type:     - Regenerative heat exchangers 7. Adiabatic Type:     - Adiabatic wheel heat exchangers 8. Run-Around Coil Type:     - Run-around coil heat exchangers These heat exchangers are used in various applications, including: - Air conditioning - Heating - Ventilation - Refrigeration - Heat recovery - Industrial processes Each type of hea...