Using (2) the latent heat removed from the air can be calculated as The relative humidity of the air is 70% at the start and 100% at the end of the cooling process.įrom the Mollier diagram we estimate the water content in the hot air to be 0.0187 kg water/kg dry air, and the water content in the cold air to be 0.0075 kg water/kg dry air. Latent evaporation heat for water can be calculated asĭw gr = humidity ratio difference (grains water/lb dry air)ĭw lb = humidity ratio difference (lb water/lb dry air)Īn air flow of 1 m 3/s is cooled from 30 to 10 oC. estimate humidity with the Mollier diagram.H we = latent heat evaporization water ( 2454 kJ/kg - in air at atmospheric pressure and 20 oC)ĭw kg = humidity ratio difference (kg water/kg dry air) Latent heat due to the moisture in air can be calculated in SI-units as: Sensible Heat Load and Required Air Volume Chart (pdf).Sensible heat load and required air volume to keep the temperature constant at various temperature differences between make up air and room air: = 21.6 (Btu/hr) Sensible Heat Load and Required Air Volume Chart Using (1b) the sensible heat added to the air can be calculated as
Using (1) the sensible heat added to the air can be calculated as Q = air volume flow (cfm, cubic feet per minute)ĭt = temperature difference ( oF) Example - Heating Air, Sensible HeatĪn air flow of 1 m 3/s is heated from 0 to 20 oC. The sensible heat in a heating or cooling process of air (heating or cooling capacity) can be calculated in SI-units asĬ p = specific heat of air (1.006 kJ/kg oC)
0 kommentar(er)
