The moisture holding capacity of air increases dramatically with increased temperature as indicated in the diagrams below.
Air Moisture Holding Capacity - SI Units
Moisture holding capacity of air - kg water per kg dry air:
Air Moisture Holding Capacity - Imperial Units
Moisture holding capacity of air - lb water per lb dry air:
Moisture holding capacity of air - lb water per 1000 cubic feet dry air:
Note - the moisture holding capacity of air at 100oF (38 oC) is 10 times the moisture holding capacity of air at 30oF (~ 0 oC). This is a very important observation - especially when working with drying processes where air is used to transport moisture away from process and products.
- it is in general good energy economy to increase the air temperature in a dryer as much as possible! - the increased moisture transport capacity of air at higher temperature out-weights the increased energy-consumption for heating the dry air to higher temperature!
Moist and humid air - psychrometric charts, Mollier diagrams, air-condition temperatures and absolute and relative humidity and moisture content.
Steam & condensate systems- properties, capacities, pipe sizing, systems configuration and more.
Thermodynamics of steam and condensate systems.
Dry air is a mechanical mixture of nitrogen, oxygen, argon and several other gases in minor amounts.
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.
The drying force of air depends on the air moisture holding capacity and the water surface to air evaporation capacity.
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 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.
The mass of water vapor present in moist air - to the mass of dry air.
Maximum water content in humid air vs. temperature.
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.
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.
Air in the steam will lower the surface temperatures in heat exchangers - and less heat will be transferred.
Water may condensate when air is cooled in air conditioning systems.
Maximum cooling tower efficiency is limited by the cooling air wet-bulb temperature.
Dehumidifying by cooling, adsorption or absorption.
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 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.
Pressure, temperature and volume in a perfect ideal gas like moist air (air with water vapor).
Draw HVAC diagrams online with this Google Drive drawing tool.
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 the mix of dry air and water vapor - moist humid air.
Psychrometric table with humid air properties like saturation pressure, specific volume, enthalpy and entropy.
Dry and wet bulb temperatures, saturation pressure, water vapor weight, specific volume, heat 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
Saturation pressure of water vapor in moist air vs. temperature.
Weight of water vapor in air
Calculate the moisture content in products like wood on wet and dry basis.
Calculating heat removed with air by measuring the wet bulb temperature.