Fundamentals & Engineering
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
Hydropneumatic Tank Sizing
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.
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: 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.
Digital Tools & Resources
Trane Air Conditioning Clinic Books
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 – Residential Hvac Loads And Duct Sizes
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.
Refrigerant Container Colors
This guideline is intended for the guidance of the industry, including manufacturers, engineers, installers, contractors and users.
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.
Refrigerants P-H Diagram
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 Equipment Life Expectancy
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: