Articles on Psychrometrics and HVAC
Guides to psychrometrics and the psychrometric chart for HVAC engineers, in IP units.
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Air Conditioning Design on the Psychrometric Chart: Step by Step
Designing air conditioning with the psychrometric chart: design conditions, air mixing and cooling capacity. A worked example of an office for 100 people.
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Air Humidity Calculation: All the Psychrometric Formulas
A full reference of psychrometric equations: saturation vapor pressure (Buck, Magnus), humidity ratio, enthalpy, dew point and density. With examples.
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Air Humidification in HVAC: Steam, Adiabatic or Ultrasonic?
Comparing humidification options in HVAC — steam, adiabatic, ultrasonic. Capacity calculation, hygiene and how each appears on the psychrometric chart.
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Desiccant Dehumidification: Silica Gel, Zeolites and Desiccant Wheels
Desiccant dehumidification with silica gel and desiccant wheels: the principle, the psychrometric chart and uses in industry, pharma and storage.
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Evaporative Cooling: Principle, Efficiency, Psychrometric Chart
How evaporative (adiabatic) cooling works, calculating saturation efficiency and plotting it on the psychrometric chart. Direct vs. indirect cooling.
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Dew Point Calculation: Formulas, Tables, Online Calculator
How to calculate dew point from dry-bulb temperature and relative humidity. Magnus–Tetens, ASHRAE comparison, and worked examples in IP units.
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Calculating Moist Air Enthalpy: Formula, Tables, Psychrometric Chart
How to calculate moist air enthalpy from temperature and humidity. ASHRAE IP formula plus worked examples of heating and cooling coil capacity.
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Moist Air Processes: Heat, Cool, Humidify, Dry
Heating, cooling, humidification and drying on the psychrometric chart — the four basic processes with examples and capacity calculations.
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The Psychrometric Chart: A Complete Guide for HVAC Engineers
Learn to read the psychrometric chart, plot air-treatment processes and export the result to your submittal. Calculations per ASHRAE Fundamentals 2021.
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Relative Humidity: What It Is, Why It Shifts, How to Measure It
What relative humidity is, why it changes with temperature, and how to measure it. Recommended levels for homes, museums and data centers.
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Thermal Comfort and the PMV/PPD Index: Calculation per ISO 7730
What the PMV and PPD indices are, how thermal comfort is calculated and the role of air humidity. Standards ASHRAE 55 and ISO 7730.
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Wet-Bulb Temperature: Physics, Measurement, and the Psychrometric Chart
What wet-bulb temperature is, how a psychrometer measures it and where to find it on the psychrometric chart. Dew point difference and Sprung equation.
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What Is Psychrometrics? A Guide to the Science of Moist Air
Psychrometrics made clear: humidity ratio, enthalpy, dew point and the psychrometric chart. Practical uses in HVAC, drying and building science.
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