Mechanical Systems

Mechanical Systems

Mechanical systems primarily deal with occupant comfort (HVAC) and movement (Vertical Transportation). The Mechanical Code of the Philippines sets the standards for these installations.

Air Conditioning Systems

Types of AC

1. Window Type: Self-contained unit for small rooms.
2. Split Type: Compressor outside, evaporator inside. Quiet and efficient.
3. Package Type: Larger units for commercial spaces.
4. Centralized (Chiller): Uses chilled water to cool air via Air Handling Units (AHUs). Best for large buildings.

Refrigeration Cycle

The core principle of AC:

1. Compression: Refrigerant gas is compressed (gets hot).
2. Condensation: Heat is rejected outside (gas becomes liquid).
3. Expansion: Pressure drops (liquid gets cold).
4. Evaporation: Heat is absorbed from the room (liquid becomes gas).

Vertical Transportation

Elevators

• Traction Elevators: Use ropes and counterweights. Suitable for mid-to-high rise.
• Hydraulic Elevators: Use a piston. Suitable for low-rise (< 6 floors).
• Machine Room-Less (MRL): Modern traction elevators without a rooftop machine room.

Escalators

Moving staircases for high-volume continuous traffic between floors.

• Angle of Inclination: Typically 30 degrees.
• Width: 600mm, 800mm, or 1000mm steps.

Fire Protection Interface

Mechanical systems must shut down or enter specific modes during a fire:

• Stair Pressurization: Fans blow air into stairs to keep smoke out.
• Smoke Extraction: Fans pull smoke out of atriums.
• AC Shutdown: Prevents spreading smoke through ducts.

Application: Cooling Load Estimation

Summary

Mechanical systems account for a significant portion of a building's energy use. Efficient design involves selecting the right system type for the building scale and integrating passive cooling strategies to reduce the load.