#RADIATOR CALCULATION TOOL WINDOWS#

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.ДЇrom 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 asДw gr = humidity ratio difference (grains water/lb dry air)Дw lb = humidity ratio difference (lb water/lb dry air)ДЄn 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)Дw 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)Дt = temperature difference ( oF) Example - Heating Air, Sensible HeatДЄn air flow of 1 m 3/s is heated from 0 to 20 oC. The U-value of the ceiling is 0.7 W/(mВІ K).The sensible heat in a heating or cooling process of air (heating or cooling capacity)В can be calculated in SI-units asД¬ p = specific heat of air (1.006 kJ/kg oC) Similarly, we include the heat loss through ceiling only if the room is on the top floor. In our calculator, we include the heat loss through floor only if this is the ground floor.

#RADIATOR CALCULATION TOOL WINDOWS#

We have set the U-value of windows to 2,5 W/(mВІ K) and external doors to 2,4 W/(mВІ K). A large quantity of heat is lost through them. Finally, in the advanced mode, you can decide on the number of windows and external doors. However, we should take into account only outside walls. We also need to know the total area of the walls. If you wish, in the advanced mode, you can set the U-value by hand. very well insulated: 11' thick cavity wall with extra insulation, U-value = 0.6 W/(mВІ K).mediocre insulation: 11' thick cavity wall, U-value = 1.0 W/(mВІ K).no extra insulation: solid brick wall, 9' thick, U-value = 2,2 W/(mВІ K).In our calculator we have provided 3 options: First, we should specify the type of insulation. The heat loss through walls can be estimated in the following way. U-value is the U-value of the material.We compute the loss through a single surface from the equation: The total heat loss is a sum of losses through walls, floor, and ceiling. To compute the heat loss, we need to sum heat loss through all the surfaces of the room and take into account different characteristics of the materials used in the construction. In general, the heat transfer is proportional to the temperature difference. Heat flows only between regions of different temperature, so if the temperature is the same, there is no flow of heat. The last factor is the difference of the temperature. For example, a 11' brick wall might have U of order 1 W/(m K), whereas a standard window might have U-value five times larger. It specifies the transfer of heat through one square meter of a material divided by the difference in temperature. A common characteristic is a heat transfer coefficient, also called U-value. Among other things, this means that they should have particular properties when it comes to heat transfer. Materials used in the constructions should comply with specific standards. The second point touches upon characteristics of the materials. The first point is simple, the larger the surface, the more heat can be transferred at the same time. the area of a surface through which the heat flows.Three factors influence the heat transfer: Heat loss is the effect of the heat transfer (in watts) from inside to outside.

Radiator calculation tool