Fundamentals & Engineering
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.
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.
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.
Standards & Compliance
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.
HVAC Ventilation Design: Corridor/Lift Lobby Smoke Extract
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.
HVAC Ventilation Design: Car Parking CO System
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.
HVAC Ventilation Design: Car Parking Make-Up Ventilation Rate By Velocity
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.
HVAC Ventilation Design: Tobacco/Smoking Area Ventilation Rates
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.
Digital Tools & Resources
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.
Refrigerant Ph Diagram (Part 2)
This article is a continuation of our older article, which was well received by users, so we decided to update the P-H Diagram list and provide you with a more complete list of the world’s commercial refrigerants. You can easily access the high quality refrigerant chart by clicking on the refrigerants listed in the table.
Carrier Plv Pro Download
Carrier’s PLV Pro is a software tool that empowers consulting engineers to make objective and informed decisions about their chiller plant design that go beyond Full Load and IPLV metrics. Results are provided in a professional report or .csv format for further analysis. The tool is for professionals who need a quick and free-of-charge alternative to detailed energy modeling analyses.
Coolselector Download
Coolselector®2 (from Danfoss company) helps to optimize energy consumption and increase efficiency in any HVACR system. Run unbiased calculations based on a set of operating conditions — such as cooling capacity, refrigerant, evaporation, and condensation temperature — and then select the best components for your design.
Air Conditioning Condensate calculator
Air conditioning condensate is the water that is produced as a result of the cooling process in an air conditioning system. When the air conditioning system cools the air in a building, it removes moisture from the air, which condenses on the cool coils of the air conditioning system. This condensation is collected and drained away through a condensate drain pipe. The water that is collected in the condensate drain is typically referred to as air conditioning condensate.
Pipe Pressure Drop Calculations: Essential Equations and Guidelines
Explore the essentials of pipe pressure drop calculations, including key factors affecting pressure drop, commonly used equations, and practical tips for optimizing fluid transportation systems. Learn about software and tools that can assist in streamlining your calculations and enhance the efficiency of your projects. In this blog post, we discussed the importance of understanding pipe pressure drop calculations and their relevance across various industries. We introduced key factors affecting pressure drop, such as pipe diameter, length, flow rate, fluid properties, and pipe roughness. We also examined several equations for calculating pressure drop, including the Darcy-Weisbach, Hazen-Williams, and Colebrook-White equations, discussing their applicability and limitations.
mcquay duct sizer Download
The McQuay Duct Sizer is a specialized software tool designed for HVAC professionals to assist in the accurate and efficient sizing of air ducts. This tool is essential for ensuring optimal performance and energy efficiency in HVAC systems. The McQuay Duct Sizer is available for free download.
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
Download HVAC-Cx: The Essential Building HVAC Systems Commissioning Tool
As buildings continue to evolve toward higher efficiency and more sophisticated control strategies, tools like HVAC-Cx become increasingly valuable. The software’s ability to systematically detect faults, prioritize issues, and assist with active commissioning represents a significant advancement in building operations technology.