A side-by-side comparison of EN 12845 and NFPA 13 sprinkler design: classes, densities and areas, hose allowance, durations, spacing, pressures and what it means on a project.
EN 12845 vs NFPA 13: Key Differences for Designers Read More »
The fall-of-potential method step by step: where to drive the probes, why 62 %, how to check the plateau and how to judge the result for TT, LPS and substation earths.
How to Measure Earth Electrode Resistance (Fall-of-Potential) Read More »
Twelve duct design mistakes that leave systems noisy, short of air or expensive to run, from skipping the index run to flat rectangular ducts and unspecified leakage, with what to do instead.
12 Common Duct Design Mistakes Read More »
Dry pipe for freezing, single-interlock preaction for water-sensitive rooms, double interlock for freezers: how they work, the design area rules and how to choose.
Dry Pipe vs Preaction: Choosing the Sprinkler System Type Read More »
EN 12056 discharge units and IPC drainage fixture units side by side: how each turns fixtures into a pipe size, and the same 10-flat stack sized both ways.
Drainage Pipe Sizing: EN 12056 DU vs IPC DFU Read More »
How to turn a list of fixtures into a realistic peak flow and a pipe size with EN 806-3 loading units or IPC fixture units, with a worked 10-flat riser example.
Domestic Water Pipe Sizing with Fixture Units (EN 806-3 and IPC) Read More »
How to design condensate traps and drains for AHUs, fan coils and cassettes: seal height from the drain pan pressure, plinth height, falls, air breaks, condensate quantities and pump interlocks.
Condensate Drain Trap Design for AHUs and FCUs Read More »
A fast, defensible way to estimate the head of a closed chilled water pump from the index circuit, with typical component losses, a worked 900 kW example at 229 kPa and the mistakes that oversize pumps.
Chilled Water Pump Head: A Quick Estimate Read More »
A quick first design for jet fan car park ventilation: total airflow by area rate or air changes, jet fan thrust and airflow, spacing and count, gas sensing and fire-mode pointers, worked for a 5000 m² basement.
Car Park Ventilation with Jet Fans: Quick Design Read More »
Two quick methods for tray width (sum of diameters and area fill), a worked riser example, and the grouping factors and spans that make a tray schedule hold up.
Cable Tray Sizing: Fill, Spacing and Derating in Practice Read More »