Fans (supply, exhaust, return)

Fans play a crucial role in HVAC systems, responsible for:

1.Air circulation:

Moving air through the system and building.

2.Pressure control:

Maintaining pressure differences between spaces.

3.Heat transfer:

Facilitating heat exchange between air and surfaces.

Types of fans:

1.Supply fans:

Deliver conditioned air to occupied spaces.

2.Exhaust fans:

Remove air from occupied spaces.

3.Return fans:

Draw air back into the system for re-conditioning.

Key characteristics:

1.Flow rate:

Measured in CFM (cubic feet per minute).

2.Pressure:

Measured in inches of water gauge (in wg).

3.Efficiency:

Measured by fan efficiency grade (FEG) or fan motor efficiency.

4.Noise level:

Measured in decibels (dB).

Factors affecting fan performance:

1.Ductwork and system design.

2.Fan selection and sizing.

3.Motor and drive type.

4.Maintenance and cleanliness.

Maintenance tips:

1.Regular cleaning of fan blades and housing.

2.Lubrication of moving parts.

3.Inspection of fan belts and motors.

4.Balancing of fan airflow.

Proper fan selection, installation, and maintenance ensure efficient and effective HVAC system operation.

Comments

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...

HVAC common unit converter chart

Here's a comprehensive HVAC unit converter chart: Volume Flow Rate 1.CFM (Cubic Feet per Minute) to CMH (Cubic Meters per Hour): 1 CFM ≈ 1.699 CMH 2.CFM to m³/s (Cubic Meters per Second): 1 CFM ≈ 0.000472 m³/s Airflow Velocity 1.FPM (Feet per Minute) to m/s (Meters per Second): 1 FPM ≈ 0.00508 m/s 2.m/s to FPM: 1 m/s ≈ 196.85 FPM Energy and Power 1.BTU/h (British Thermal Units per Hour) to kW (Kilowatts): 1 BTU/h ≈ 0.000293 kW 2.Tons of Refrigeration to kW: 1 Ton ≈ 3.517 kW Pressure 1.Inches of Water Gauge (in wg) to Pascals (Pa): 1 in wg ≈ 249.08 Pa 2.PSI (Pounds per Square Inch) to kPa (Kilopascals): 1 PSI ≈ 6.895 kPa Temperature 1.°F (Fahrenheit) to °C (Celsius): °C = (°F - 32) × 5/9 2.°C to °F: °F = °C × 9/5 + 32 Additional Conversions Length 1.Inches to Millimeters: 1 inch = 25.4 mm 2.Feet to Meters: 1 foot = 0.3048 meters Area Square Feet to Square Meters: 1 sq ft = 0.0929 sq m Volume Gallons to L...

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 engineers

Search This Blog