Building Services and Installations
Building Services and Installations tests the design and verification of water, drainage, ventilation, electrical and thermal systems, mainly through CTE DB-HS and DB-SUA, REBT and RITE.
Core requirements
DB-HS3 requires ventilation of dwellings and car parks; DB-HS4 sets supply flow and pressure; DB-HS5 sets drainage diameters, slopes and ventilation. REBT governs low-voltage electrical installations; RITE governs thermal installations; DB-SUA covers accessibility and safety of use.
Coordination
Design must be coordinated: a drainage gradient can conflict with structural beams, and a boiler flue can conflict with a facade opening. Commissioning and maintenance matter: a system that meets the drawing but not the test does not comply.
Worked example
A four-storey building has 300 kPa at the mains, a static rise of 12 m (about 118 kPa) and 50 kPa of pipe and meter losses. Residual pressure = 300 − 118 − 50 = 132 kPa. If the most unfavourable outlet needs 100 kPa, no booster set is required; if it needs 150 kPa, one is.
Traps
- Confusing l/s with m³/h.
- Checking pressure only at the ground floor.
- Omitting ventilation for an underground car park.
- Ignoring the interaction between drainage slopes and ceiling voids.