Engineering Systems and Networks (Water, Heat, Gas, Ventilation)
Water supply and drainage
Know the components of internal and external water supply: sources, pumping stations, storage, distribution networks, and the distinction between potable and process water. Understand drainage systems: gravity sewers, gradients, manholes, and the requirement for ventilation of the network. Know the minimum and maximum flow-velocity criteria to avoid silting and scouring.
Heating and gas
Heating systems are classified by heat carrier (water, steam, air) and by layout (one-pipe, two-pipe). Know the role of the expansion tank, circulation pump, and balancing valves. Gas supply systems require pressure regulation, safety shut-off, and ventilation of rooms; gas pipelines have defined pressure classes and clearance requirements.
Ventilation and air conditioning
Understand natural versus mechanical ventilation, air exchange rates, and the requirement for balancing supply and exhaust. Know the fire-safety role of smoke control systems and fire dampers in ducts crossing fire compartments.
Traps
- Confusing the purpose of a circulation pump with that of an expansion tank.
- Assuming gas pipelines can share ducts with other services - they cannot.
- Forgetting that smoke control systems are separate from comfort ventilation and have their own acceptance tests.
- Mixing up minimum sewer gradient requirements for different pipe diameters.
Worked example
A room of 60 m³ requires 3 air changes per hour. Required airflow = 60 × 3 = 180 m³/h. If the supply duct delivers 150 m³/h, the deficit must be covered by additional supply or reduced exhaust; balancing is mandatory before acceptance.
Rule of thumb
For every engineering system, verify three acceptance items: pressure/flow test, balancing, and documentation of the as-built scheme.