What is the specific weight of water?
The specific weight, also known as the unit weight, is the weight per unit volume of a material. A commonly used value is the specific weight of water on Earth at 4°C, which is 9.807 kN/m3 or 62.43 lbf/ft3.
How do you find the specific weight of air?
The ratio between weight and volume is called specific weight. The symbol used for specific weight is γ and the SI unit of measurement is N/m3….Example of specific weight (gas): air.
| Temperature [°C] | Specific weight [N/m3] |
|---|---|
| 60 | 10.4 |
| 80 | 9.81 |
| 100 | 9.28 |
| 200 | 7.33 |
What is the specific volume of air?
Table of common specific volumes
| Substance name | Density | Specific volume |
|---|---|---|
| (kg/m3) | (m3/kg) | |
| Air | 1.225 | 0.816 |
| Ice | 916.7 | 0.00109 |
| Water (liquid) | 1000 | 0.00100 |
How do you find the specific volume of air?
D. Specific volume is defined as the number of cubic meters occupied by one kilogram of matter….Specific Volume Formulas
- ν = V / m where V is volume and m is mass.
- ν = 1 /ρ = ρ-1 where ρ is density.
- ν = RT / PM = RT / P where R is the ideal gas constant, T is temperature, P is pressure, and M is the molarity.
What is specific volume of moist air?
Specific Volume of Moist Air per unit Mass of Dry Air and Water Vapor. Specific volume is defined as the total volume of dry air and water vapor mixture per kg of dry air and water vapor (SI-units). The specific volume can be expressed as: v = V / ma + mw (11)
What is humid volume formula?
In unit volume of humid gas, the mass mv of vapor of molecular weight Mv is given by: or. Similarly, the mass mG of dry gas of molecular weight MG is: Thus the humidity, H = mv/mG = pv/(p − pv) · Mv/MG. For the air water system, therefore H = pv/(p − pv) · 18/29 approximately.
What is specific volume in HVAC?
SPECIFIC VOLUME – The volume of a substance per unit of mass; i.e., standard air 13.33 cubic feet per pound. The reciprocal of density.
What is specific volume of soil?
V = 1 + e = specific volume = volume containing unit volume of solid material.
What is the symbol of specific volume?
Typically specific volume uses the symbol v. The density of a substance is defined as the mass per unit volume, and it is therefore the reciprocal of the specific volume. Density is designated by the symbol ρ. Specific volume and density are intensive properties.
What is specific volume in psychrometric chart?
Specific volume of air in psychrometric chart is defined as the number of cubic meters occupied by one kilogram of a dry air. So units of specific volume is m3 kg-1.
What is meant by psychrometric chart?
A psychrometric chart presents physical and thermal properties of moist air in a graphical form. It can be very helpful in troubleshooting and finding solutions to greenhouse or livestock building environmental problems.
What is psychometry in RAC?
Psychometry : It is the branch of science which deals with the study of the mixture of dry air and water vapor. In air conditioning estimations air is taken as a mixture of dry air and water vapor. The principles of psychometry apply to any physical system consisting of gas-vapor mixtures.
Can WBT be higher than DBT?
Hence WBT is always less than DBT for unsaturated air and is equal to DBT for saturated air. For saturated air R.H. = 100%. Specific Humidity: Specific or absolute humidity or humidity ratio or moisture content is defined as the ratio of mass of water vapour to the mass of dry air in a given sample of air.
What is relation between DBT and WBT if the relative humidity is 100%?
At 100% relative humidity, the wet-bulb temperature is equal to the air temperature (dry-bulb temperature); at lower humidity the wet-bulb temperature is lower than dry-bulb temperature because of evaporative cooling.
What is DB WB in HVAC?
DB temp is indicative of the sensible heat content of the air. Wet Bulb (WB) temperature is the temperature of air as registered by a thermometer whose temperature sensing bulb is covered by a material (cloth) soaked in water and exposed to a rapidly moving current of air.