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Latest Blogs
ASHRAE 183: The Industry Standard for HVAC Load Calculations
Learn what ASHRAE Standard 183 requires for HVAC load calculations and what engineering design software needs to produce compliant, audit-ready results.
How to Calculate Air Changes Per Hour
Learn the ACH formula, how to calculate air changes per hour from airflow and room volume, and typical values by room type.
Do Heat Pumps Work in Cold Weather? How They Extract Heat From Air Below 0°F
Yes, heat pumps can work below 0°F (-18°C). Here’s how cold-climate systems extract heat, maintain capacity, and handle defrost cycles.
Latest Charts
How to Read a Psychrometric Chart (Without Losing Your Mind)
This psychrometric chart guide breaks down every property, process, and worked example in plain English.
Ductulator Chart: Practical Guide for Mechanical Engineers (Free Download)
Duct size directly affects noise, energy, and layout, which is why you should use the Ductulator Chart to get it right.
A Guide To Air Duct Pressure Drop Calculation For Optimal HVAC Performance
Discover the science behind efficient HVAC systems! Explore h2x Engineering’s insightful blog on Air Duct Pressure Drop Calculation for optimal airflow design.
Latest Formulas
How to Calculate Air Changes Per Hour
Learn the ACH formula, how to calculate air changes per hour from airflow and room volume, and typical values by room type.
CFM Calculation Formula: 4 Ways to Calculate Required Airflow
Four CFM calculation formulas for ventilation, cooling load, and duct sizing, with a fully worked example.
Friction Factor: The Small Coefficient Driving Pressure Drop
If you want to size a pipe or duct accurately, you must calculate the friction factor: a technical, iterative process with multiple variables (Re, material, diameter, temperature). This guide explains the methods and shows you how to apply them, so your pressure drop calculations are always precise.
Latest Spreadsheets
FREE Pipe Volume Spreadsheet
Access h2x’s free pipe volume spreadsheet to streamline calculations, optimise design, and enhance efficiency in piping projects.
h2x vs. Spreadsheets
Since its launch back in 1985, Microsoft’s spreadsheet application Excel has gone on to become accepted as the leading program for the management and calculation of data.
Hardy Cross Method – Sizing a Ring Main (FREE Spreadsheet)
Flow rate and friction loss in a pipe network system can be difficult to calculate. When the pipe network is in a ring main (also known as a closed-loop) formation, the calculations are extra difficult.
This difficult calculation is very common for fire hydrant ring main size designs and the ring main design calculations.
Latest Calculators
FREE Water Flow Rate Calculator
Water Flow Rate Calculator Use this free Water Flow Rate Calculator to estimate flow rates from plumbing fixtures…
FREE Heat Loss Calculator
Heat Loss Calculator Use the Heat Loss Calculator to calculate heat loss in any room or building by…
FREE Ductulator
Ductulator Use our free online Ductulator to calculate velocity, pressure drop, Reynolds number, and friction factor based on…
Resources
ASHRAE 183: The Industry Standard for HVAC Load Calculations
Learn what ASHRAE Standard 183 requires for HVAC load calculations and what engineering design software needs to produce compliant, audit-ready results.
Do Heat Pumps Work in Cold Weather? How They Extract Heat From Air Below 0°F
Yes, heat pumps can work below 0°F (-18°C). Here’s how cold-climate systems extract heat, maintain capacity, and handle defrost cycles.
CFM Calculation Formula: 4 Ways to Calculate Required Airflow
Four CFM calculation formulas for ventilation, cooling load, and duct sizing, with a fully worked example.
HVAC System Selection for Any Building Size
A practical guide for mechanical engineers on when and why to specify each HVAC system selection type.
How to Eliminate Data Entry Errors in Plumbing Design
Why disconnected tools and manual data transfer create calculation errors in plumbing design, and how engineers can remove the risk.
Hydronic Snow Melt Systems: How to Size & Design Them Correctly
A complete technical guide to hydronic snow melt design for HVAC engineers: what to calculate, what to avoid, and how to get it right before the slab is poured.
Gas Pipe Sizing Guide: How to Size Natural Gas and LPG Pipework
A practical gas pipe sizing guide using International Fuel Gas Code (IFGC) equations, with metric and imperial units for natural gas and LPG systems.
MEP Design and Estimating: Bridging the Gap
A look at how design and estimating function in MEP projects today, where the process breaks down, and what closing the gap could mean for contractors and engineers.
Heat Load Calculation Software: Why Engineers Are Moving Beyond Trane TRACE and Carrier HAP
Legacy heat load calculation software like Trane TRACE and Carrier HAP no longer fits the modern engineering workflow. Here’s what a genuine alternative actually looks like.
Air-to-Water Heat Pump Retrofit: 4 Scenarios Where AWHPs Shine
Not every building is ready for a heat pump, but some are perfect for one. Here’s how to identify the retrofit scenarios where air-to-water heat pumps deliver their full potential.
Calculating Heating and Cooling Loads: What’s the Difference?
Calculating heating and cooling loads requires understanding two opposite problems: heat gain in summer and heat loss in winter. Both must be accounted for in every complete HVAC system design.
Why Revit Falls Short for Design Engineers
Revit handles modelling and documentation well, but design engineers still need better calculation tools.