Engineering & Knowledge

Pipe Insulation Guideline

Learn the essential standards and best practices for proper pipe insulation to maximize thermal efficiency and prevent condensation in engineering systems.

Refrigerant Piping – part2

Learn the critical steps and best practices for installing and maintaining refrigerant piping systems to ensure optimal HVAC performance and efficiency.

Pipe Pressure Drop Calculations: Essential Equations and Guidelines

Learn how to accurately calculate pipe pressure drops using essential equations and guidelines to ensure optimal fluid flow and system efficiency.

Sensible, Latent, and Total Heat

Master the core concepts of sensible, latent, and total heat to accurately analyze and design efficient HVAC systems.

Water Flow Rate Calculations in HVAC

Learn how to accurately perform water flow rate calculations to ensure optimal efficiency and performance in HVAC systems.

Refrigeration Expansion Valve Sizing and Selection Process

Proper expansion valve selection is critical for refrigeration system efficiency and reliability. This guide outlines the systematic approach to sizing and selecting expansion valves based

Refrigeration Evaporator Sizing and Selection

The evaporator is a critical component in any refrigeration system, serving as the heart of the cooling process. Proper sizing and selection of evaporators directly

Infiltration Rules Of Thumb

Learn the essential rules of thumb for calculating building infiltration to improve the accuracy of your HVAC load calculations and energy models.

HVAC Ventilation Design: Air Intake Minimum Separation Distance

Air intake minimum separation distance represents critical design criteria for ensuring adequate outdoor air quality by maintaining appropriate distances between fresh air intakes and potential contamination sources.

HVAC Load Estimation: Diversity Factor

Diversity factor represents a critical design parameter in HVAC load calculations, accounting for the statistical probability that all heat-generating components in a building will not operate simultaneously

HVAC Load Estimation: Infiltration Heat Gain and Loss

Infiltration represents uncontrolled air exchange between outdoor and indoor environments, significantly impacting both heating and cooling loads in all building types. Accurate infiltration estimation is essential for

HVAC Load Estimation: Internal Heat Gain from Equipment and Appliances

Equipment and appliances represent significant internal heat sources in modern buildings, often comprising the largest component of cooling loads in commercial and industrial facilities. Accurate estimation of

HVAC Load Estimation: Internal Heat Gain from People and Occupants

Internal heat gain from people represents a significant component of HVAC cooling loads, particularly in high-occupancy buildings. Accurate estimation of occupant heat gain is essential for proper

HVAC Load Estimation: Glazing U-Values and Shading Coefficient (SC) Values

Fenestration thermal and solar properties are critical parameters in HVAC load calculations, significantly impacting both heating and cooling loads. Understanding glazing U-values and shading coefficients is essential

HVAC Load Estimation: Construction U-Values for Walls, Roofs, and Partitions

Building envelope thermal properties form the backbone of HVAC load calculations, directly determining heat transfer rates and system sizing requirements. Accurate U-value determination is essential for

HVAC Psychrometric Processes: Charts, Calculations, and Air Treatment Applications

Psychrometric processes form the scientific foundation of HVAC system design, enabling engineers to analyze air conditions and design effective air treatment systems. Understanding these processes is essential

HVAC Design Equations: Air, Fan, Pump, and Hydronic System Calculations

HVAC engineers rely on fundamental equations to design, size, and optimize mechanical systems. These mathematical relationships form the backbone of proper system design, ensuring accurate performance predictions

ASHRAE Guidelines on HVAC Equipment Life Expectancy

Learn how to apply ASHRAE guidelines on HVAC equipment life expectancy to optimize your building’s maintenance schedules and replacement budgeting.

Ductulator and Pressure Loss (friction) calculator

Streamline your HVAC design process with our comprehensive digital Ductulator and Pressure Loss Calculator. This all-in-one tool allows you to instantly convert duct shapes, determine optimal sizing based on friction or velocity constraints, and accurately calculate total pressure loss and airflow rates for complex ductwork systems.

Air mixing calculator

Accurately determine the final thermodynamic state of combined airstreams. Input flow rates and air properties to instantly calculate mixed air conditions, streamlining AHU fresh-air and return-air mixing design.

Vapor pressure deficit (VPD) calculator

Optimize humidity control for HVAC, greenhouse cultivation, and agricultural drying. Use this Vapor Pressure Deficit (VPD) calculator to accurately determine moisture potential, enabling better transpiration rates, crop yield optimization, and precise environmental management.

Psychrometric state calculator

Instantly determine the complete psychrometric state of moist air using just two inputs. Enter dry-bulb temperature alongside any single humidity parameter to automatically calculate dew point, wet-bulb, relative humidity, enthalpy, specific volume, and density for precise HVAC design and analysis.

Plenum Box Size Calculator

Free online plenum box size calculator for HVAC engineers. Enter airflow (CFM or m³/h) and target velocity to instantly get recommended width, height, length, and depth for supply and return plenum boxes, based on ACCA Manual D sizing practice.

Expansion Tank Sizing Calculator

Size bladder, diaphragm, or plain-steel expansion tanks for closed hydronic systems in seconds. This calculator applies thermal-expansion and pressure-ratio principles from Steven T. Taylor’s ASHRAE-referenced sizing method and the ASME Boiler and Pressure Vessel Code, Section VI, to compute the minimum required tank acceptance volume for hot water, chilled water, and mixed-temperature systems. Supports US and SI units, all four major tank styles, an optional piping-expansion credit, and a built-in ASME/UMC/IMC cross-check for 170–230°F systems — with clear pass/warning/invalid status and next-step guidance for tank selection and precharge verification.

Fundamentals & Engineering