基础与工程
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
在这篇文章中，我们将继续进行有关如何确定制冷剂管道尺寸的全面培训。我们将涵盖该过程的所有重要方面，包括确定管道尺寸、压降和其他因素。我们还将讨论制冷剂管路尺寸、制冷剂管路等效长度以及如何确定等效长度等主题。通过本培训，您将拥有在任何情况下准确、正确地确定制冷剂管道尺寸的知识和信心。
标准与合规性
HVAC Ventilation Design: Exhaust Air Ventilation By Rate and ACH
Complete guide to HVAC exhaust air ventilation design using ASHRAE, CIBSE, and Carrier standards covering rate calculations, ACH requirements, and specialized applications for effective contaminant removal and energy efficiency.
HVAC Ventilation Design: Outdoor Air Ventilation By Rate and ACH
Complete guide to HVAC outdoor air ventilation design using ASHRAE, CIBSE, and Carrier standards covering rate calculations, ACH requirements, and building-specific applications for optimal indoor air quality.
HVAC Ventilation Design: Indoor Air Quality and Air Contaminants
Complete guide to HVAC indoor air quality and air contaminant management using ASHRAE, CIBSE standards covering contaminant identification, control strategies, and advanced treatment technologies for healthy indoor environments.
HVAC Ventilation Design: Air Intake Minimum Separation Distance
Complete guide to HVAC air intake minimum separation distances using ASHRAE 62.1 standards covering contamination source requirements, measurement methods, and compliance strategies for optimal outdoor air quality protection.
HVAC Ventilation Design: Air Classifications
Complete guide to HVAC air classifications using ASHRAE 62.1 and CIBSE standards covering air quality categories, contamination levels, filtration requirements, and ventilation strategies for optimal indoor environmental control.
HVAC Ventilation Design: General Schematic and Equations
Complete guide to HVAC ventilation design using ASHRAE 62.1 standards covering calculation procedures, system schematics, and modern ventilation strategies for optimal indoor air quality and energy efficiency.
HVAC Load Estimation: Fouling Factor
Complete guide to fouling factors in HVAC load estimation using Carrier water conditioning standards for accurate heat transfer equipment sizing and comprehensive water quality management strategies.
HVAC 负载估算：多样性因素
Complete guide to diversity factors in HVAC load estimation using CIBSE and Carrier standards for accurate system sizing that reflects realistic building operation patterns and prevents equipment oversizing.
HVAC 负荷估算：按建筑类型划分的室内设计条件和系统要求
Complete guide to indoor design conditions for HVAC load estimation covering temperature, humidity, air quality, and specialized requirements for residential, commercial, industrial, healthcare, and specialty building applications using ASHRAE, CIBSE, and Carrier standards.
HVAC 负载估算：渗透热增益和热损失
Complete guide to infiltration in HVAC load estimation using ASHRAE, CIBSE, and Carrier standards for accurate assessment of uncontrolled air exchange and its impact on heating and cooling loads.
数字工具和资源
Cooltools软件下载
– 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.
管道压降计算：基本方程和指南
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下载
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.