Size a VAV box from the zone load, set a minimum airflow the sensor can measure and the ventilation needs, and pick an inlet that stays quiet.
VAV Box Selection: Sizing, Minimum Flow and Noise Read More »
Estimate the fan duty of a pressurised stair from closed-door leakage and open-door velocity, then check the door opening force and relief.
Stair Pressurisation: Quick Airflow Design Read More »
Size commercial kitchen hood exhaust from hood length and appliance duty, then balance it with make-up air and size the grease duct, with a worked 4 m heavy-duty wall canopy at 2480 L/s.
Commercial Kitchen Hood Exhaust Airflow: Quick Sizing 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 »
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 »
How ASHRAE 62.1 and EN 16798-1 set outdoor air rates, side by side, with the same 400 m² office calculated under both (220–275 L/s vs 560 L/s) and what the difference means on a project.
ASHRAE 62.1 vs EN 16798: Ventilation Rates Compared Read More »
Quick rules to size an air handling unit before the selection software is open: airflow from the sensible load, casing and coil velocities, coil and fan duties and the plant room space, with a worked 2.0 m³/s DOAS example.
AHU Sizing: Quick Rules for Airflow, Coil and Footprint Read More »
How to size supply ducts with the equal friction method, check velocities for noise, count fitting losses and calculate the index run that selects the fan, with a fully worked office floor branch.
Duct Sizing Guide: Equal Friction, Fittings and the Index Run Read More »