Engineering & Knowledge - HVAC-R & Solar Engineering Resource

Fundamentos e engenharia

Pump Construction (Part1)

In 1689 the physicist Denis Papin invented the centrifugal pump and today this kind of pump is the most used around the world. The centrifugal pump is built on a simple principle: Liquid is led to the impeller hub and by means of the centrifugal force it is flung towards the periphery of the impellers. The construction is fairly inexpensive, robust and simple and its high speed makes it possible to connect the pump directly to an asynchronous motor.

What Is Corrosion?

Corrosion is usually referred to as the degradation of the metal by chemical or electrochemical reaction with its environment, see figure 1. When considered broadly, corrosion may be looked upon as the tendency of the metal to revert to its natural state similar to the oxide from which it was originally melted. Only precious metals, such as gold and platinum are found in nature in their metallic state. – Types of corrosion – Uniform corrosion – Pitting corrosion – Crevice corrosion – Intergranular corrosion – Selective corrosion – Erosion corrosion – Cavitation corrosion – Stress corrosion cracking (SCC) – Corrosion fatigue – Galvanic corrosion

Expansion Valves Selection

The expansion valve regulates the amount of compressed liquid refrigerant moving into the evaporator. It removes pressure from the liquid refrigerant to allow expansion or change of state from a liquid to a gas in the evaporator. In order to properly select Expansion Valves one should pay attention to the items that we mention in this post.

Water Tube Versus Fire Tube Boilers

Water tube boilers and fire tube boilers are two different types of steam boilers that are commonly used in industrial and commercial applications. Both types of boilers use a system of tubes to generate steam, but they differ in the way that the tubes are arranged and the way that the hot gases from the burner pass through the tubes.

Water Hammer (Part1)

Under unfavorable circumstances, damage due to water hammer may occur in pipelines measuring more than one hundred meters and conveying only several tenths of a liter per second. But even very short, unsupported pipelines in pumping stations can be damaged by resonant vibrations if they are not properly anchored. By contrast, the phenomenon is not very common in building services systems, e.g. in heating and drinking water supply pipelines, which typically are short in length and have a small cross-section.

Capillary Tube Refrigeration

A refrigeration capillary tube is a small, narrow tube that is used in refrigeration systems to control the flow of refrigerant. It is typically made of copper or other highly conductive metal, and is used in conjunction with a compressor, evaporator, and condenser to transfer heat from one location to another. The capillary tube is placed between the evaporator and the compressor in the refrigeration system, and it acts as a metering device to control the flow of refrigerant.

Refrigeration Formulas and Calculations

These formulas are commonly used in the field of refrigeration and air conditioning to calculate various performance parameters of a refrigeration system such as compression work, compression power, coefficient of performance, net refrigeration effect, capacity, compressor displacement, heat of compression, volumetric efficiency, and compression ratio. These formulas are based on the thermodynamics principles and are generally used to evaluate the performance of the refrigeration system and to optimize its design.

The coefficient of velocity (Cv)

Cv, or coefficient of velocity, is a measure of the flow capacity of a valve. It represents the number of gallons per minute (GPM) of water at 60°F that will flow through a valve with a one-inch opening at a pressure drop of one pound per square inch (PSI). Cv can be calculated using various formulas, such as the one based on water at 60F and one that takes into account the specific gravity of the fluid. Cv is a theoretical value and it may vary depending on the actual conditions of the valve. When selecting a valve for a specific application, it is important to consider the Cv in relation to the flow rate and pressure drop requirements of the system, as well as other factors such as ease of maintenance, cost, and safety.

Pipe Insulation Guideline

Pipe insulation is crucial for maintaining energy efficiency, temperature control, condensation control, noise reduction, and safety. ASHRAE provides specific thickness recommendations for different pipe sizes and temperature ranges in its standard 90.1. When selecting pipe insulation based on ASHRAE standards, it’s important to consider the temperature, pipe size, environmental considerations, fire resistance, and energy efficiency.

Refrigerant Piping – part2

In this post, we will be continuing our comprehensive training on how to size refrigerant piping. We will cover all the important aspects of this process, including determining the pipe size, pressure drop, and other factors. We will also discuss topics such as sizing refrigerant lines, equivalent length for refrigerant lines, and how to determine equivalent length. With this training, you will have the knowledge and confidence to size refrigerant piping accurately and correctly in any situation.

HVAC Ventilation Design: Lift/Elevator Pressurization

Complete guide to HVAC lift/elevator pressurization design using BS 5588-4 standards covering pressure control, airflow calculations, and elevator system integration for effective emergency vertical transportation protection.

HVAC Ventilation Design: Staircase Pressurization + Relief Vent Sizing

Complete guide to HVAC staircase pressurization and relief vent sizing design using ASHRAE and BS standards covering pressure control, airflow calculations, and relief system integration for effective emergency egress protection.

HVAC Ventilation Design: Corridor/Lift Lobby/Atrium Make-Up/Pressurization

Complete guide to HVAC corridor, lift lobby, and atrium make-up air and pressurization design using CIBSE and ASHRAE standards covering pressure control, airflow calculations, and fire safety integration for effective emergency protection.

HVAC Ventilation Design: Atrium Smoke Extract

Complete guide to HVAC atrium smoke extraction design using CIBSE and ASHRAE standards covering smoke layer management, extraction calculations, and advanced fire safety integration for large-volume space protection.

Projeto de ventilação HVAC: Extração de fumaça do corredor/elevador

Complete guide to HVAC corridor and lift lobby smoke extraction design using CIBSE fire engineering standards covering smoke removal, pressure management, and life safety system integration for effective emergency ventilation.

Projeto de ventilação HVAC: Sistema CO de estacionamento de automóveis

Complete guide to HVAC car parking CO detection systems using NFPA 720 standards covering carbon monoxide monitoring, alarm systems, ventilation integration, and safety protocols for parking facility protection.

Projeto de ventilação HVAC: taxa de ventilação de reposição de estacionamento por velocidade

Complete guide to HVAC car parking make-up ventilation design using ASHRAE velocity-based methods covering air movement calculations, system integration, and performance optimization for effective parking facility ventilation.

HVAC Ventilation Design: Car Parking Extract Ventilation Rate

Complete guide to HVAC car parking extract ventilation design using CIBSE and BS standards covering CO control, air change rates, and specialized applications for safe and efficient parking facility ventilation systems.

HVAC Ventilation Design: Commercial Kitchen Ventilation Rates (Hood/Canopy, Ceiling Extract/Makeup)

Complete guide to HVAC commercial kitchen ventilation design using ASHRAE, CIBSE, and VA standards covering hood exhaust rates, makeup air requirements, and specialized applications for effective contaminant control and energy efficiency.

Projeto de ventilação HVAC: taxas de ventilação para áreas de fumo/fumantes

Complete guide to HVAC smoking area ventilation design using CIBSE standards covering high-performance ventilation rates, specialized system requirements, and health protection strategies for tobacco use areas.

Belimo SelectPro – Download grátis

Download SelectPro desktop app free. Size and select valves, actuators, and sensors with export builder, quote generator, and centralized reference documents. For HVAC engineers and contractors.

Taxas de expansão térmica para materiais de tubos comuns

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.

Calculadora de expectativa de vida de equipamentos HVAC

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.

Soluções de software BIM para aplicações modernas de HVAC

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.

Oportunidades de Carreira Hvac

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.

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