Engineering & Knowledge

Fundamentals & Engineering

Space and Zone Airflow Sizing Calculations in HVAC Systems

Following our previous discussion on the systematic 9-step procedure for designing cooling and heating systems, it’s essential to understand the technical aspects of airflow sizing

Design Procedures for Cooling-Only Systems: Detailed Airflow Calculation Methodology

this technical supplement provides detailed insights into the critical airflow calculation methods essential for Step 3: Calculate Required Zone and Space Supply Airflow Rates. Understanding these calculation approaches enables engineers to select the most appropriate sizing method for specific project requirements.

Design Procedures for Heating-Only Systems: Airflow Calculation Methods and Technical Considerations

Proper airflow calculations are essential for system performance, ensuring thermal comfort while optimizing energy efficiency. Understanding the mathematical foundation behind these calculations enables engineers to make informed decisions when selecting the most appropriate sizing method for specific project requirements.

Refrigeration Expansion Valve Sizing and Selection Process

The proper selection and sizing of refrigeration expansion valves is a systematic process requiring careful consideration of multiple parameters. Selecting the right expansion valve involves understanding system requirements, calculating correct capacities, and accounting for operating conditions such as subcooling and pressure drop.

Refrigeration Evaporator Sizing and Selection

Evaporator sizing and selection represent critical elements in refrigeration system design. The process requires a methodical approach that considers not only the cooling load but also system integration, refrigerant properties, application requirements, and energy efficiency goals.

Lighting Rules Of Thumb (HVAC)

Using lighting rules of thumb for final design of HVAC and lighting.

Infiltration Rules Of Thumb

The infiltration rate is the volumetric flow rate of outside air into a building, typically in cubic feet per minute (CFM) or liters per second (LPS). The air exchange rate, (I), is the number of interior volume air changes that occur per hour, and has units of 1/h.

Cooling Load Calculation Procedure

Cooling Load Calculation Procedure for HVAC Design. From Obtain Building Characteristics to Outdoor Design Weather Conditions and indoor design temperature to be maintained in each space.

The Geometry Behind Solar Energy Calculations

Solar Geometric Angles are all critical to the calculation of solar energy on any given surface at some orientation. To calculate the energy balance across any time scale with respect to the incident solar radiation, you must know the geometric relationships that define the spherical realities of planetary motion relative to the sun for specific tilted surfaces on the planet.

Hvac Load Calculations

The accurate calculation of heating and cooling loads is essential to provide a sound bridge between fundamental building design decisions and an operating building. If loads are substantially underestimated, occupants and users will likely be hot or cold. If loads are substantially overestimated, equipment will be oversize (usually wasting money, reducing efficiency, increasing energy consumption, and often imperiling comfort).

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Standards & Compliance

HVAC Duct Design: Duct Fittings Friction Loss

Complete guide to HVAC duct fittings friction loss using Carrier standards covering loss coefficients, pressure drop calculations, and system optimization for efficient air distribution design.

HVAC Duct Design: Dampers, Attenuators, and Coils Friction Loss

Complete guide to HVAC dampers, attenuators, and coils friction loss using SMACNA standards covering pressure drop calculations, component selection, and system optimization for efficient air distribution design.

HVAC Duct Design: Duct Round to Rectangular Equivalent

Complete guide to HVAC round-to-rectangular duct equivalency using ASHRAE standards covering conversion formulas, performance considerations, and system optimization for space-constrained installations.

HVAC Duct Design: Duct Friction Loss

Complete guide to HVAC duct friction loss calculations using ASHRAE standards covering friction charts, pressure drop analysis, and system optimization for efficient air distribution design.

HVAC Duct Design: Duct Pressure Classification

Complete guide to HVAC duct pressure classification using SMACNA standards covering pressure class selection, construction requirements, and testing protocols for safe and efficient ductwork systems.

HVAC Duct Design – Sizing Contaminant-Extraction Ducts (Smoke | Grease | Gases | Dry & Moist Dust)

ASHRAE’s Pocket Guide lists minimum conveying velocities that keep contaminants airborne while they travel through exhaust ductwork. Table 2.9 (2013 edition, Ch. 02, pp. 60

HVAC Duct Design: Commercial Kitchen Duct Sizing

Complete guide to commercial kitchen duct sizing using ASHRAE and NFPA standards covering exhaust hood design, grease management, fire safety, and make-up air systems for food service operations.

HVAC Duct Design: Duct Sizing by Velocity & Noise Criteria (NC)

Complete guide to HVAC duct sizing using velocity and noise criteria with ASHRAE and CIBSE standards covering acoustic design, velocity limits, and noise control for sensitive applications.

HVAC Duct Design: Duct Sizing by Equal Friction Method

Complete guide to HVAC duct sizing using the equal friction method with SMACNA and ASHRAE standards covering calculation procedures, friction rate selection, and system optimization for effective air distribution design.

HVAC Duct Design: Duct Sizing SMACNA Recommendations

Complete guide to HVAC duct sizing using SMACNA recommendations covering equal friction, velocity, and static regain methods with design calculations and system optimization for effective air distribution.


Digital Tools & Resources

Rates Of Thermal Expansion For Common Pipe Materials

Effortlessly calculate rates of thermal expansion for common pipe materials with our interactive calculator. Get accurate data, design insights, and actionable tables for metals and plastics—essential for HVAC engineers, designers, and consultants focused on system reliability and energy efficiency.

HVAC Equipment Life Expectancy Calculator

We’ve created a professional HVAC equipment life expectancy calculator. The application provides comprehensive calculations for determining the remaining useful life of various HVAC equipment types.

BIM Software Solutions for Modern HVAC Applications

As the HVAC industry continues to evolve in 2025, Building Information Modeling (BIM) has become an indispensable tool for professionals seeking to optimize design, installation, and maintenance processes. For HVAC engineers, contractors, and technicians, selecting the right BIM software can significantly impact project efficiency and outcomes. Let’s explore the most effective BIM solutions for HVAC applications.

Mcquay Softwares Download

McQuay (As part of Daikin Industries) is one of the largest air conditioning, heating, ventilating and refrigeration companies in the HVAC/R industry. Therefore, we decided to make some softwares that this company has introduced to the industry based on their experience and knowledge available for download.

Bell & Gossett Selection Softwares

#Xylem Bell & Gosset #Selection, #Sizing & #CAD Tools and #Softwares

Hvac Career Opportunities

The HVAC/R (heating, ventilating, and air conditioning / refrigeration) industry is rapidly changing due to advancements in technology being spurred on by the need for increased energy efficiencies. Accordingly, the career opportunities open to an individual seeking employment in HVAC fields can be divided roughly into four categories, each dependent upon a different type or degree of education and/or training.

Pipe Schedules Tables

Pipe Schedule (SCH) is a standard that measures the nominal wall thickness of a pipe. The pipe schedule number is non-dimensional and depends on the nominal pipe size, internal pipe working pressure, and the material used for the pipe wall.

Piping Tools (Excel Files)

More than 165 spreadsheets (excel xls files) for a comprehensive range of calculation in Fluid, Thermal and piping engineering.

Daikin Revit Files

DAIKIN APPLIED RESOURCE LIBRARY – REVIT FILES Rooftop Systems Air Handlers – Outdoor Air Cooled Chillers Water Cooled Chillers Fan Coils Self-Contained Water Source Heat Pump Unit Ventilators

Cooltools Software Download

– Cycle analysis (process design) – comparison of one stage direct expansion cycle and one stage flooded cycle. – System sizing – calculation of component sizes from general criteria. – System simulation – calculating operating conditions in a system with known components. Component calculations – calculation of – components efficiencies and outlet conditions. – Evaluation of operation – evaluation of system efficiency. – Process investigation – e.g. moist air calculations.