HVAC engineers

CALCULATE MOTOR PUMP SIZE Calculate Size of Pump having following Details Static Suction Head(h2)=0 Meter Static Discharge Head (h1)=50 Meter. Required Amount of Water (Q1)=300 Liter/Min. Density of Liquid (D) =1000 Kg/M3 Pump Efficiency (pe)=80% Motor Efficiency(me)= 90% Friction Losses in Pipes (f)=30% CALCULATIONS: Flow Rate (Q) =Q1x1.66/100000=300×1.66/100000=0.005 M3/Sec Actual Total Head (After Friction Losses) (H) = (h1+h2)+((h1+h2)xf) Actual Total Head (After Friction Losses) (H)=50+(50×30%)= 65 Meter. Pump Hydraulic Power (ph) = (D x Q x H x9.87)/1000 Pump Hydraulic Power (ph) = (1000 x 0.005 x 65 x9.87)/1000 =3KW Motor/ Pump Shaft Power (ps)=ph/pe=3/80% = 4KW Required Motor Size: ps / me=4/90% = 4.5 KW Required Size of Motor Pump = 4.5 HP or 6 HP

Cooling Coil Calculation When selecting a cooling coil, many engineers jump straight to software... but understanding the fundamentals is what makes the difference on-site. 1. Cooling Load (Q) Start with the basic equation: Q = m × Cp × ΔΤ Where: m = air mass flow rate (kg/s) Cp = specific heat (~1.02 kJ/kg.K) ΔT = temperature difference (°C) 2. Airflow Method (Most Practical) In real projects, we usually use airflow: Q1.2 x CFM × ΔT (or in SI) Q = p x V x Cp × ΔT Example: Airflow = 5000 CFM Entering air = 30°C Leaving air = 15°C ΔT = 15°C Q1.2 x 5000 × 15 = 90,000 Btu/hr (~7.5 TR) 3. Coil Selection Parameters Don't stop at load calculation. Always verify: Entering air DB/WB (important for latent load) Chilled water temperature (e.g., 7/12°C) Face velocity (recommended: 2-2.5 m/s) Number of rows & fins spacing 4. Key Field Insight A common mistake is oversizing the coil: Leads to low humidity control Causes short cycling Reduces system efficiency 5. Pro Tip from Site If your su...