Psychrometric + Hydraulic Calculator

Chilled Water Coil Condensate
Gravity Drain Pipe Sizing

Calculates condensate flow, sensible / latent / total coil heat removal, and recommends minimum gravity drain pipe size for HDPE and Copper Type B pipework.

Outdoor Design Conditions

Steps 01 – 02 · City select or manual entry

01Input Method

02Design Basis

City

Air-Side Parameters

Steps 03 – 06 · Outside air, return air, room conditions

03Outside Air Flow Rate

L / s

04Return Air Flow Rate

L / s

05Return Air Dry Bulb

°C dry bulb (room temperature)

06Room Relative Humidity

% RH

Off-Coil Conditions & Pipe Options

Steps 07 – 10 · Coil leaving conditions, material, slope

07Off-Coil Dry Bulb (°C)

°C leaving air dry bulb

08Off-Coil Wet Bulb (°C)

°C leaving air wet bulb

09Pipe Material

10Drain Slope

Manning's n = 0.009 · half-full pipe

Design basis: Condensate flow from psychrometric moisture removal. Heat removal via enthalpy method (AIRAH DA09). Pipe capacity per Manning's equation (n = 0.009, half-full flow assumption per AS 3500.2). Results are indicative only and do not replace professional engineering judgement.

Awaiting Input

Complete all inputs and tap Run Calculation

Results are ready. Print or save as PDF — the layout will reformat automatically for A4.

Chilled Water Coil CondensateGravity Drain Pipe Sizing

Chilled Water Coil Condensate
Gravity Drain Pipe Sizing