The study of moist and humid air - psychrometric charts, Mollier diagrams, air-condition temperatures and absolute and relative humidity and moisture content
Absolute humidity is the actual mass of water vapor present in the air water vapor mixture.
Dry air is a mechanical mixture of nitrogen, oxygen, argon and several other gases in minor amounts.
Density and specific volume of air varies with elevation above sea level.
Air density at pressure ranging 1 to 10 000 bara (14.5 - 145000 psi) and constant selected temperatures.
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.
Diffusion coefficients (D12) for gases in large excess of air at temperatures ranging 0 - 400 °C.
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.
Basic air changing state processes - heating, cooling, mixing, humidifying and dehumidifying by adding steam or water - psychometric diagrams and the Mollier charts.
Air can be humidified by adding water or steam.
Estimate the amount of steam required (lb/h in 100 cfm) in humid air.
Using steam to humidify air.
Relative humidity in moist air can estimated by measuring the dry and wet bulb temperature.
The mass of water vapor present in moist air - to the mass of dry air.
Maximum water content in humid air vs. temperature.
The moisture holding capacity of air increases with temperature.
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.
Prandtl number for air vs. temperature and pressure.
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.
Psychrometric chart for air at barometric pressure 29.921 inches of Mercury and temperature ranging 20oF to 120oF.
Figures and tables with isobaric (Cp) and isochoric (Cv) specific heat of air at constant temperature and pressure ranging 0.01 to 10000 bara
Online calculator with figures and tables showing specific heat (Cp and Cv) of dry air vs. temperature and pressure. SI and imperial units.
Online calculator with figures and tables showing air thermal conductivity vs. temperature and pressure. SI and imperial units.
Figures and tables withdry air thermal diffusivity vs. temperarure and pressure. SI and Imperial units.
Thermal properties of air at different temperatures - density, viscosity, critical temperature and pressure, triple point, enthalpi and entropi, thermal conductivity and diffusivity and more.
The drying force of air depends on the air moisture holding capacity and the water surface to air evaporation capacity.
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.
Saturation pressure and maximum water content in compressed air.
Maximum cooling tower efficiency is limited by the cooling air wet-bulb temperature.
Classification of dehumidifiers.
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.
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 can be used to determine the state of humid air.
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 tutorial.
The Great Sensible Heat Factor is the ratio sensible to total heat in a cooling coil.
The influence of humidity on the apparent temperature and the heat index.
Classification of heat recovery efficiencies - temperature efficiency, moisture efficiency and enthalpy efficiency - online heat exchanger efficiency calculator.
Heat gain from persons in air conditioned spaces - in btu/hr.
Enthalpy change and temperature rise when heating humid air without adding moisture.
Pressure, temperature and volume in a perfect ideal gas like moist air (air with water vapor).
Recommended indoor comfort temperatures vs. outdoor temperatures
Recommended indoor relative humidity vs. outdoor relative humidity and temperature.
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.
Human metabolic heat gain in air conditioned rooms.
The change in state wwhen mixing moist air - enthalpy, heat, temperature and specific humidity.
Cooling and dehumidifying processes of moist and humid air - sensible and latent cooling.
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.
Humidity ratio of moist air to humidity ratio of saturated moist air.
Density of moist air vs. pressure ranging 75 - 1000 mmHg.
Density of the mix of dry air and water vapor - moist humid air.
Sensible and latent heat of moist air.
Mole fraction of water vapor is the ratio of water molecules to air and water molecules.
Psychrometric table with humid air properties like saturation pressure, specific volume, enthalpy and entropy.
Psychrometric Chart in I-P Units for high temperatures at sea level and with a barometric pressure of 29.921 inHG.
Psychrometric chart in I-P Units for low temperature at sea level and barometric pressure 29.921 inHG.
Psychrometric chart in I-P Units at 5000 feet and barometric pressure 24.896 inHG.
Psychrometric chart in I-P Units at 7500 feet and barometric pressure 22.653 inHG.
Calculate moist air properties in SI and Imperial units with this online calculator.
Dry and wet bulb temperatures, saturation pressure, water vapor weight, specific volume, heat and more.
Dry and wet bulb temperature, specific volume, relative humidity, enthalpy and more.
Relative humidity in moist air is the ratio of partial vapor pressure to air pressure.
Specific volume of moist air is defined as the total volume of humid air per mass unit of dry air
Specific humidity of moist air vs. relative humidity, water vapor and air density.
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.
The relationship between the psycrometric chart and the Mollier diagram.
Vapor pressures vs. dry and wet bulb temperatures in moist air.
Saturation pressure of water vapor in moist air vs. temperature.
Weight of water vapor in air
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 summer and winter design temperatures and relative humidity for US states and cities.
Recommended relative humidity in production and process environments - like libraries, breweries, storages and more.
Calculating heat removed with air by measuring the wet bulb temperature.
Room Sensible Heat Factor - RSHF - is defined as the sensible heat load divided by the total heat load in a room
Sensible heat is dry heat causing change in temperature but not in moisture content
Sensible Heat Ratio - SHR - is defined as the sensible heat or cooling load divided by the total heat or cooling load
The relationship between volume, pressure, temperature and quantity of a gas, including definition of gas density.
The Universal and Individual Gas Constants in fluid mechanics and thermodynamics. Individual gas constants for the most common gases.
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.
The Wet Bulb Globe Temperature can be used to measure the general Heat-Stress index.