Engineering & Knowledge

Fundamentals & Engineering

Design Procedures for Heating-Only Systems: An 8-Step Methodology

Designing effective heating-only HVAC systems requires a methodical approach that ensures adequate capacity while avoiding oversizing. The following 8-step procedure provides a comprehensive framework for designing these systems, focusing on peak heating loads to determine appropriate equipment sizing.

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.

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Standards & Compliance

HVAC Load Estimation: Internal Heat Gain from Infrastructure Components (Pipes, Ducts, Tanks, AC Motors)

Complete guide to internal heat gain from HVAC infrastructure components including pipes, ducts, tanks, and motors using Carrier standards for accurate load estimation and system design.

HVAC Load Estimation: Internal Heat Gain from Equipment and Appliances

Complete guide to internal heat gain from equipment and appliances in HVAC load estimation using ASHRAE, CIBSE, and Carrier standards for accurate system sizing and equipment integration.

HVAC Load Estimation: Internal Heat Gain from Lighting

Complete guide to internal heat gain from lighting systems in HVAC load estimation using ASHRAE, CIBSE, and Carrier standards for accurate system sizing and lighting-HVAC integration.

HVAC Load Estimation: Internal Heat Gain from People and Occupants

Complete guide to internal heat gain from people and occupants in HVAC load estimation using ASHRAE, CIBSE, Carrier, and NFPA standards for accurate system sizing and design.

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

Complete guide to glazing U-values and shading coefficients for HVAC load estimation using ASHRAE, CIBSE, and Carrier standards for accurate fenestration thermal and solar analysis.

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

Complete guide to construction U-values for walls, roofs, and partitions in HVAC load estimation using ASHRAE, CIBSE, and Carrier standards for accurate thermal analysis.

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

Complete guide to psychrometric processes in HVAC design covering sensible/latent cooling, heating, humidification, dehumidification, and evaporative cooling using ASHRAE and CIBSE standards.

HVAC Cooling and Heating Load Estimation: Outdoor Conditions and Climate Data

Comprehensive guide to outdoor climate data for HVAC load estimation using ASHRAE, CIBSE, and Carrier standards. Essential weather parameters for accurate system sizing and energy analysis.

HVAC System Selection and Design Strategy: Professional Standards and Guidelines

Comprehensive guide to HVAC system selection and design strategy using ASHRAE, SMACNA, and Carrier standards. Learn professional methodologies for optimal system selection and performance optimization.

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

Comprehensive guide to essential HVAC design equations covering air, fan, pump, and hydronic system calculations. Reference standards from SMACNA, ASHRAE, and Carrier for professional engineering applications.

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Digital Tools & Resources

Air Filters Efficiency Classification

ASHRAE 52.2: Filter testing was originated from America in 1930 (ASHVE and AFI code). It was then reviewed and modified in 1967 and 1968. ASRHAE collaborated with American National Standard Institude (ANSI) in 1992 to create ASHRAE-ANSI 52.1. Finally updated to ASHRAE 52.2 in 2007.

Psychrometric Programming Functions

ibrary of psychrometric functions to calculate thermodynamic properties of air for Python, C, C#, Fortran, JavaScript and VBA/Excel

Refrigerants in 2025: Properties, Applications, and Compatibility

As the HVAC and refrigeration industry continues to evolve with environmental regulations and technological advancements, understanding refrigerant properties remains crucial for engineers, technicians, and facility managers. This comprehensive guide provides an updated overview of common refrigerants, their compositions, and applications in today’s market.

Carrier Hap Software

Carrier’s Hourly Analysis Program is two powerful tools in one package – versatile features for designing HVAC systems for commercial buildings AND powerful energy analysis capabilities for comparing energy consumption and operating costs of design alternatives.

Trace 700 Software

TRACE 700 enables building designers to optimize the building, system and equipment designs on the basis of energy utilization and life-cycle cost. The Trane software for TRACE 700 facilitates analysis of the energy and economic effects of virtually any chiller plant configuration by allowing users to manipulate a wide range of variables and create a profile of their specific building.

Download EVAP-COND 5.0: The Ultimate Heat Exchanger Simulation Tool for HVAC Engineers

Whether you’re designing a new heat exchanger, optimizing an existing system, or researching alternative refrigerants, EVAP-COND provides the detailed analysis capabilities needed to make informed decisions. I encourage all HVAC engineers and researchers to explore this powerful simulation tool and experience firsthand how it can transform your approach to heat exchanger design.

Heat Transfer Textbook Download

The book is meant for juniors, seniors, and first-year graduate students. And to those who choose to learn the subject on their own, and to practicing engineers who use it as a reference. Whether one studies alone or with a class, learning means posing, then answering, one’s own questions.

Flexible Duct Calculator

Flexible Duct Calculator based on four different methods. Based on Friction Loss, Based on Duct Diameter, Equivalent Rectangular Duct, Equivalent Round Duct Diameter. Also table of Maximum Recommended Supply Velocity.

Air Change Cfm Calculator

The rate at which air is exchanged (in the premises) represents another method of measuring ventilation capacity & effectiveness. Air exchange rate is typically expressed in Air Changes per Hour – “ACH”. Air changes per hour can be estimated by determining the total air supplied to, and removed from, the premises “total air exchange” or the outdoor (fresh) air supplied to, and removed from, the premises “outdoor air exchange”. We invite you to experience how this calculator can transform your workflow. Whether you’re specifying a new system, troubleshooting an existing installation, or teaching the next generation of HVAC professionals, this tool was built with your needs in mind.

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