Air Psychrometrics
The study of moist and humid air - psychrometric charts, Mollier diagrams, air-condition temperatures and absolute and relative humidity and moisture content
Air - Absolute Humidity
Absolute humidity is the actual mass of water vapor present in the air water vapor mixture.
Air - Composition and Molecular Weight
Dry air is a mechanical mixture of nitrogen, oxygen, argon and several other gases in minor amounts.
Air - Density and Specific Volume vs. Altitude
Density and specific volume of air varies with elevation above sea level.
Air - Density vs. Pressure and Temperatures
Air density at pressure ranging 1 to 10 000 bara (14.5 - 145000 psi) and constant selected temperatures.
Air - Density, Specific Weight and Thermal Expansion Coefficient vs. Temperature and Pressure
Online calculator, figures and tables showing density, specific weight and thermal expansion coefficients of air at temperatures ranging -100 to 1600 °C (-140 to 2900 °F) at atmospheric and higher pressure - Imperial and SI Units.
Air - Diffusion Coefficients of Gases in Excess of Air
Diffusion coefficients (D12) for gases in large excess of air at temperatures ranging 0 - 400 °C.
Air - Dynamic and Kinematic Viscosity
Online calculator, figures and tables with dynamic (absolute) and kinematic viscosity for air at temperatures ranging -100 to 1600°C (-150 to 2900°F) and at pressures ranging 1 to 10 000 bara (14.5 - 145000 psia) - SI and Imperial Units.
Air - Heating, Cooling, Mixing, Humidifying or Dehumidifying Processes
Basic air changing state processes - heating, cooling, mixing, humidifying and dehumidifying by adding steam or water - psychometric diagrams and the Mollier charts.
Air - Humidifying by Adding Steam or Water
Air can be humidified by adding water or steam.
Air - Humidifying with Steam - Imperial Units
Estimate the amount of steam required (lb/h in 100 cfm) in humid air.
Air - Humidifying with Steam - SI units
Using steam to humidify air.
Air - Humidity measured by the Dry and Wet Bulb Temperature
Relative humidity in moist air can estimated by measuring the dry and wet bulb temperature.
Air - Humidity Ratio
The mass of water vapor present in moist air - to the mass of dry air.
Air - Maximum Moisture Carrying Capacity
Maximum water content in humid air vs. temperature.
Air - Moisture Holding Capacity vs. Temperature
The moisture holding capacity of air increases with temperature.
Air - Molecular Weight and Composition
Dry air is a mixture of gases where the average molecular weight (or molar mass) can be calculated by adding the weight of each component.
Air - Prandtl Number
Prandtl number for air vs. temperature and pressure.
Air - Properties at Gas-Liquid Equilibrium Conditions
Properties of air change along the boiling and condensation curves (temperature and pressure between triple point and critical point conditions). An air phase diagram included.
Air - Psychrometric Chart for Standard Atmospheric Conditions - Imperial Units
Psychrometric chart for air at barometric pressure 29.921 inches of Mercury and temperature ranging 20oF to 120oF.
Air - Specific Heat vs. Pressure and Constant Temperature
Figures and tables with isobaric (Cp) and isochoric (Cv) specific heat of air at constant temperature and pressure ranging 0.01 to 10000 bara
Air - Specific Heat vs. Temperature and Constant Pressure
Online calculator with figures and tables showing specific heat (Cp and Cv) of dry air vs. temperature and pressure. SI and imperial units.
Air - Thermal Conductivity vs. Temperature and Pressure
Online calculator with figures and tables showing air thermal conductivity vs. temperature and pressure. SI and imperial units.
Air - Thermal Diffusivity vs. Temperature and Pressure
Figures and tables withdry air thermal diffusivity vs. temperarure and pressure. SI and Imperial units.
Air - Thermophysical Properties
Thermal properties of air at different temperatures - density, viscosity, critical temperature and pressure, triple point, enthalpi and entropi, thermal conductivity and diffusivity and more.
Air Drying Force
The drying force of air depends on the air moisture holding capacity and the water surface to air evaporation capacity.
Ammonia Gas - Density vs. Temperature and Pressure
Online calculator with figures and tables showing density and specific weight of ammonia for temperatures ranging -50 to 425 °C (-50 to 800 °F) at atmospheric and higher pressure - Imperial and SI Units.
Compressed Air - Water Content
Saturation pressure and maximum water content in compressed air.
Cooling Tower Efficiency
Maximum cooling tower efficiency is limited by the cooling air wet-bulb temperature.
Dehumidifiers
Classification of dehumidifiers.
Dry Air - Thermodynamic and Physical Properties
Thermodynamic properties of dry air - specific heat, ratio of specific heats, dynamic viscosity, thermal conductivity, Prandtl number, density and kinematic viscosity at temperatures ranging 175 - 1900 K.
Dry Air and Water Vapor - Density and Specific Volume vs. Temperature - Imperial Units
Density and specific volume of dry air and water vapor at temperatures ranging 225 to 900 degF (107 to 482 degC).
Dry Bulb, Wet Bulb and Dew Point Temperatures
Dry Bulb, Wet Bulb and Dew Point temperatures can be used to determine the state of humid air.
Evaporation from a Water Surface
Evaporation of water from a water surface - like a swimming pool or an open tank - depends on water temperature, air temperature, air humidity and air velocity above the water surface - online calculator.
Evaporative Cooling
Evaporative cooling tutorial.
Great Sensible Heat Factor - GSHF
The Great Sensible Heat Factor is the ratio sensible to total heat in a cooling coil.
Heat Index vs. Humidity
The influence of humidity on the apparent temperature and the heat index.
Heat Recovery Efficiences
Classification of heat recovery efficiencies - temperature efficiency, moisture efficiency and enthalpy efficiency - online heat exchanger efficiency calculator.
Human Heat Gain
Heat gain from persons in air conditioned spaces - in btu/hr.
Humid Air - Heating
Enthalpy change and temperature rise when heating humid air without adding moisture.
Humid Air vs. the Ideal Gas Law
Pressure, temperature and volume in a perfect ideal gas like moist air (air with water vapor).
Indoor Comfort Temperatures vs. Outdoor Temperatures
Recommended indoor comfort temperatures vs. outdoor temperatures
Indoor Relative Humidity vs. Outdoor Relative Humidity and Temperature
Recommended indoor relative humidity vs. outdoor relative humidity and temperature.
Latent Heat Flow
Latent heat is the heat when supplied to or removed from air results in a change in moisture content - the temperature of the air is not changed.
Metabolic Heat Gain from Persons
Human metabolic heat gain in air conditioned rooms.
Mixing of Humid Air
The change in state wwhen mixing moist air - enthalpy, heat, temperature and specific humidity.
Moist Air - Cooling and Dehumidifying
Cooling and dehumidifying processes of moist and humid air - sensible and latent cooling.
Moist Air - Daltons Law of Partial Pressure
The pressure in a mixture of dry air and water vapor - humid or moist air - can be estimated by using Daltons Law of partial pressures.
Moist Air - Degree of Saturation
Humidity ratio of moist air to humidity ratio of saturated moist air.
Moist Air - Density vs. Pressure
Density of moist air vs. pressure ranging 75 - 1000 mmHg.
Moist Air - Density vs. Water Content and Temperature
Density of the mix of dry air and water vapor - moist humid air.
Moist Air - Enthalpy
Sensible and latent heat of moist air.
Moist Air - Mole Fraction of Water Vapor
Mole fraction of water vapor is the ratio of water molecules to air and water molecules.
Moist Air - Properties
Psychrometric table with humid air properties like saturation pressure, specific volume, enthalpy and entropy.
Moist Air - Psychrometric Chart for High Temperatures at Sea Level
Psychrometric Chart in I-P Units for high temperatures at sea level and with a barometric pressure of 29.921 inHG.
Moist Air - Psychrometric Chart for Low Temperatures at Sea Level
Psychrometric chart in I-P Units for low temperature at sea level and barometric pressure 29.921 inHG.
Moist Air - Psychrometric Chart for Normal Temperatures at 5000 Feet Altitude
Psychrometric chart in I-P Units at 5000 feet and barometric pressure 24.896 inHG.
Moist Air - Psychrometric Chart for Normal Temperatures at 7500 Feet Altitude
Psychrometric chart in I-P Units at 7500 feet and barometric pressure 22.653 inHG.
Moist Air - Psychrometric Online Calculator
Calculate moist air properties in SI and Imperial units with this online calculator.
Moist Air - Psychrometric Table for Pressure 29.92 inHg.
Dry and wet bulb temperatures, saturation pressure, water vapor weight, specific volume, heat and more.
Moist Air - Psychrometric Terms
Dry and wet bulb temperature, specific volume, relative humidity, enthalpy and more.
Moist Air - Relative Humidity
Relative humidity in moist air is the ratio of partial vapor pressure to air pressure.
Moist Air - Specific Volume
Specific volume of moist air is defined as the total volume of humid air per mass unit of dry air
Moist Air - Specific vs, Relative Humidity
Specific humidity of moist air vs. relative humidity, water vapor and air density.
Moist Air - the Mollier Diagram
The Mollier diagram is a graphic representation of the relationship between air temperature, moisture content and enthalpy - and is a basic design tool for building engineers and designers.
Moist Air - Transforming the Mollier Diagram to a Psychrometric Chart - or vice versa
The relationship between the psycrometric chart and the Mollier diagram.
Moist Air - Vapor Pressure
Vapor pressures vs. dry and wet bulb temperatures in moist air.
Moist Air - Water Vapor and Saturation Pressure
Saturation pressure of water vapor in moist air vs. temperature.
Moist Air - Weight of Water Vapor
Weight of water vapor in air
Non-ideal gas - Van der Waal's Equation and Constants
The van der Waals constants for more than 200 gases used to correct for non-ideal behavior of gases caused by intermolecular forces and the volume occupied by the gas particles.
Outdoor Temperatures and Relative Humidity - US Winter and Summer Conditions
Outdoor summer and winter design temperatures and relative humidity for US states and cities.
Relative Humidity in Production and Process Environments
Recommended relative humidity in production and process environments - like libraries, breweries, storages and more.
Removing Heat with Air
Calculating heat removed with air by measuring the wet bulb temperature.
Room Sensible Heat Factor - RSHF
Room Sensible Heat Factor - RSHF - is defined as the sensible heat load divided by the total heat load in a room
Sensible Heat Flow
Sensible heat is dry heat causing change in temperature but not in moisture content
Sensible Heat Ratio - SHR
Sensible Heat Ratio - SHR - is defined as the sensible heat or cooling load divided by the total heat or cooling load
The Ideal Gas Law
The relationship between volume, pressure, temperature and quantity of a gas, including definition of gas density.
Universal and Individual Gas Constants
The Universal and Individual Gas Constants in fluid mechanics and thermodynamics. Individual gas constants for the most common gases.
Water - Saturation Pressure
Online calculator, figures and tables with water saturation (vapor) pressure at temperatures ranging 0 to 370 °C (32 to 700°F) - in Imperial and SI Units.
Wet Bulb Globe Temperature (WBGT)
The Wet Bulb Globe Temperature can be used to measure the general Heat-Stress index.