Commercial AC Plant and Chiller
- Chiller System: Uses chilled water as an indirect cooling medium instead of direct refrigerant expansion.
✅ Two Main Types:
1️⃣ Air-Cooled Chiller – Uses outdoor air to remove heat.
2️⃣ Water-Cooled Chiller – Uses cooling towers & water circulation for heat dissipation. - 📌 Quick Fact: Indirect cooling systems reduce refrigerant use & are energy-efficient.
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✅ Key Components:
1️⃣ Chiller Unit – Cools water using refrigerant.
2️⃣ Cooling Tower – Removes heat from the system.
3️⃣ Pumps & Piping – Circulates chilled water.
4️⃣ AHU (Air Handling Unit) & FCU (Fan Coil Unit) – Distribute cool air.
- ✅ AHU (Air Handling Unit):
- Large system that cools & distributes air through ductwork.
- Includes fans, cooling coils, filters, dampers.
- ✅ FCU (Fan Coil Unit):
- Smaller unit placed in rooms/zones for localized cooling.
- Works with chilled water from a central chiller.
- 📌 Quick Fact: AHUs handle large-scale cooling, while FCUs provide room-level cooling.
- Air Washers in Chilled Water System
- 🔹 Used for humidification & cooling.
🔹 Sprays water droplets to cool & purify air.
🔹 Helps in air quality improvement.
- 🔹 Used for humidification & cooling.
- Modulating Valves for Temperature Control
- ✅ Purpose: Adjusts chilled water flow to control temperature.
✅ Types:
1️⃣ 2-Way Valve – Adjusts flow to maintain set temperature.
2️⃣ 3-Way Valve – Mixes return & supply water for fine control. - 📌 Quick Fact: Modulating valves prevent overcooling & energy waste.
- ✅ Purpose: Adjusts chilled water flow to control temperature.
- Expansion Tanks
- 🔹 Absorb excess pressure in chilled water systems.
🔹 Prevents damage to pipes and pumps. - 📌 Quick Fact: Expansion tanks balance water pressure and prevent leaks.
- 🔹 Absorb excess pressure in chilled water systems.
- ✅ Humidification (Adding Moisture):
- Uses Steam, Water Spray, or Ultrasonic Mist.
- Improves air quality in cold & dry climates.
- Used in textile, paper, and hospitals.
- ✅ Dehumidification (Removing Moisture):
- Uses Cooling Coils, Desiccant Wheels, or Dehumidifiers.
- Prevents mold growth, corrosion, and discomfort.
- Used in electronics, pharma, and food storage.
- 🔹 Commercial AC Plant Components:
- Package Chiller – Compact unit for medium cooling loads.
- Screw Chiller – Uses screw compressors, suitable for large buildings.
- Reciprocating Chiller – Uses piston compressors, smaller cooling loads.
- 📌 Quick Fact: Screw chillers are more efficient than reciprocating chillers.
- AC System Controls
- 🔹 Electromechanical Controls – Thermostats, relays, timers.
🔹 Pneumatic Controls – Air-operated valves and dampers.
🔹 Electronic Controls – Sensors, microprocessors, and BMS (Building Management Systems). - 📌 Quick Fact: Modern HVAC systems use smart electronic controls for energy savings.
- 🔹 Electromechanical Controls – Thermostats, relays, timers.
- Heat Load Calculation in AC Buildings
- Sensible Heat Load – Heat from people, lights, equipment, walls.
- Latent Heat Load – Heat due to moisture (humidity) in air.
- 📌 Quick Fact: Heat load calculations help determine the correct AC size for a building.
- HVAC (Heating, Ventilation & Air Conditioning)
- Provides temperature & air quality control.
- Used in homes, offices, factories, hospitals.
- 📌 Quick Fact: HVAC saves energy by using efficient ventilation & climate control.
