基础与工程
Hvac Air Volume Calculation
The air volume for an HVAC system is calculated from the sensible heat in the conditioned space. For the typical heating and cooling unit, the calculation is for cooling because more air is needed to cool a space than to heat it. If the conditioned space can be properly cooled with a given amount of cfm, then the space can be heated correctly with the same amount of cfm.
Thermal Storage (HVAC)
Thermal energy may be stored in three main ways: – Sensible Storage – Latent Storage – Thermo-Chemical Storage. In addition, the two common thermal storage strategies employed are: – Load Levelling Strategy – Load Shifting Strategy
水力发管箱尺寸
Hydropneumatic tanks are primarily used in a domestic water system for draw down purposes when the pressure booster system is off on no-flow shutdown (NFSD). The NFSD circuitry turns the lead pump off when there is no demand on the system. While the system is off in this condition, the hydropneumatic tank will satisfy small demands on the system. Without the tank, the booster would restart upon the slightest call for flow such as a single toilet being flushed or even a minute leak in the piping system. Hydropneumatic tank sizing is dependent on two factors: – Length of time you wish the pumps to remain off in a no-flow situation. – The tank location in relation to the pressure booster.
Pump Sizing Core Concepts
Pump sizing involves matching the flow and pressure rating of a pump with the flowrate and pressure required for the process. The mass flowrate of the system is established on the process flow diagram by the mass balance. Achieving this mass flowrate requires a pump that can generate a pressure high enough to overcome the hydraulic resistance of the system of pipes, valves, and so on that the liquid must travel through. This hydraulic resistance is known as the system head.
Hvac Equations (U.S./Metric)
The heating, ventilation, and air conditioning (HVAC) equations. In both U.S. and Metric units.
Expansion Tanks
How does Boyle’s law relate to sizing expansion tanks in domestic hot water systems? what size expansion tank is required?
Expansion Tank Sizing Formulas
Expansion tanks are a necessary part of all closed hydronic systems to control both minimum and maximum pressure throughout the system. A comprehensive review of tank types and sizing procedure for expansion tanks.
Primary Secondary Pumping
– What is Primary-Secondary Pumping? – PRIMARY-SECONDARY BASICS. – PRIMARY-SECONDARY RULES, DEFINITIONS. WHEN TWO PIPING CIRCUITS ARE INTER-CONNECTED, FLOW IN ONE WILL CAUSE FLOW IN THE OTHER, T0 A DEGREE DEPENDING UPON THE PRESSURE DROP IN THE PIPING COMMON T0 BOTH.
4-Pipe And 2-Pipe Heating And Cooling Plants
A 4-pipe heating and cooling plant contains both central heating and cooling equipment and is capable of delivering heating water and chilled water to the building simultaneously through four pipes (one heating water supply, one heating water return, one chilled water supply, and one chilled water return). Heating and cooling equipment within the building that is connected to a 4-pipe system will have four pipe connections, unless the equipment provides either heating only or cooling only. In this case, the equipment would have only two pipe connections.
Constant Air Volume (CAV) Systems
HVAC air systems can be either centralized or decentralized. Centralized air systems receive their cooling and heating energy from a remote central plant. Decentralized HVAC air systems contain the central heating and cooling plant equipment within the air system itself. HVAC air systems can also be constant air volume (CAV) or variable air volume (VAV). CAV systems deliver constant supply airflow at a variable temperature. VAV systems deliver variable supply airflow at a constant temperature. CAV and VAV air systems can be further subdivided into systems that condition a single temperature zone and systems that condition multiple temperature zones.
标准与合规性
HVAC 管道设计：管道配件摩擦损失
使用开利标准的 HVAC 管道配件摩擦损失完整指南，涵盖损失系数、压降计算和高效空气分配设计的系统优化。
HVAC 管道设计：阻尼器、衰减器和线圈摩擦损失
使用 SMACNA 标准的 HVAC 阻尼器、衰减器和线圈摩擦损失完整指南，涵盖压降计算、组件选择和系统优化，以实现高效的空气分配设计。
HVAC 管道设计：圆形管道与矩形管道等效
使用 ASHRAE 标准的 HVAC 圆形管道与矩形管道等效的完整指南，涵盖转换公式、性能注意事项以及空间受限安装的系统优化。
HVAC 管道设计：管道摩擦损失
使用 ASHRAE 标准计算 HVAC 管道摩擦损失的完整指南，涵盖摩擦图表、压降分析和高效空气分配设计的系统优化。
HVAC 管道设计：管道压力分类
使用 SMACNA 标准进行 HVAC 管道压力分类的完整指南，涵盖安全高效管道系统的压力等级选择、施工要求和测试协议。
HVAC 管道设计：商业厨房管道尺寸
使用 ASHRAE 和 NFPA 标准确定商业厨房管道尺寸的完整指南，涵盖排气罩设计、油脂管理、消防安全和食品服务运营的新风系统。
HVAC Duct Design: Duct Sizing by Velocity & Noise Criteria (NC)
使用符合 ASHRAE 和 CIBSE 标准的速度和噪声标准确定 HVAC 管道尺寸的完整指南，涵盖敏感应用的声学设计、速度限制和噪声控制。
HVAC 管道设计：通过等摩擦法确定管道尺寸
使用符合 SMACNA 和 ASHRAE 标准的等摩擦法确定 HVAC 管道尺寸的完整指南，涵盖计算程序、摩擦率选择和有效空气分配设计的系统优化。
HVAC 管道设计：管道尺寸 SMACNA 建议
使用 SMACNA 建议确定 HVAC 管道尺寸的完整指南，涵盖等摩擦、速度和静态回弹方法，以及有效空气分配的设计计算和系统优化。
数字工具和资源
Trane空调诊所书籍
These clinics are comprehensive and detailed courses used to educate on the fundamentals heating, ventilating, and air conditioning (HVAC). Each clinic includes a student workbook, with corresponding quiz questions/problems.
Carrier Technical Development Programs (Tdp) Books
Technical Development Programs (TDP) are modules of technical training on HVAC theory, system design, equipment selection and application topics. They are targeted at engineers and designers who wish to develop their knowledge in this field to effectively design, specify, sell or apply HVAC equipment in commercial applications.
Rhvac – 住宅暖通空调负荷和管道尺寸
Rhvac can calculate peak heating and cooling loads (both block and room by room) for residential buildings and some light commercial applications in accordance with ACCA Manual J, D, and S. Rhvac include a complete ACCA Manual D duct sizing capability and a complete Manual S equipment selection.
制冷剂容器颜色
本指南旨在为行业提供指导，包括制造商、工程师、安装商、承包商和用户。
Refrig – Refrigeration Box Loads
Refrig quickly calculates the maximum refrigeration load in btu’s per 24 hour period for all types of refrigeration applications. Refrig has provision for all kinds of loads including: roofs, walls, partitions, floors, products, containers, infiltration, lights, equipment, people, defrost, compressor run-time, and more.
3E Plus Software
NAIMA’s FREE 3E Plus® software program makes it easy to calculate the appropriate insulation thickness necessary for any application. To ensure accuracy, the program has customizable inputs for every aspect of your job—and offers default values if your exact numbers aren’t available.
制冷剂 PH 图
The pressure-enthalpy diagram (log P/h diagram) is a very useful tool for refrigerant technicians, engineers and researchers. Since it’s not always possible to have all of these diagrams together, we decided to give you this complete pack.
HVACR 设备预期寿命
Below you can see ASHRAE chart of HVAC Equipment Life Expectancy. The chart includes a list of median life expectancy for the following types of equipment: