Air Conditioning Load Calculations, The Psychrometric Chart: Fill & Download for Free

PSYCHROMETRY is a branch of science which deals with the study of atmospheric air. In air conditioning system we need to use the psychrometric chart for heat load calculation .psychrometric chart is the graph of physical properties of moist air at a constant pressure. It is an industry-standard tool that is used to visualize the interrelationships between dry air, moisture, and energy. It plays an important role in air conditioning system. If you are responsible for the design or maintenance of any aspect of air-conditioning in buildings, a clear and comfortable understanding of the chart will make your job easier.If you want know more about psychrometry click on the link PSYCHROMETRIC CHART AND PSYCHROMETRIC PROCESSES

Not many ask questions on how to calculate the cooling capacity of an air conditioner. I mean, from an existing, functional air conditioner.The actual cooling capacity of air conditioner is not always equal to the rated capacity of air conditioner.The actual cooling capacity of an air conditioner is a function of enthalpy difference across the air entering the air conditioner at its inlet side and the air being discharged at the outlet vane of the air conditioner (both of which can be found from a psychrometric chart by plotting the actual DBT and WBT of EA and LA) and the mass flow rate of the air being conditioned.The TR calculated using this relation, will be dynamic because the load on the air conditioner is dynamic.

How do I calculate heat transfer through the open window of a room when the AC is on?You will need the area of the window, average speed of air entering (this will happen when the window faces windward side) or leaving the room through the open window (this will happen when the window faces leeward side). You can calculate the volume flow rate of the air thus. Calculate mass flow rate of air from the volume flow rate.You will need to measure the dry bulb and wet bulb temperature of the air entering the room. I say entering the room here because, even when air leaves the room, the air conditioner sucks an equivalent amount of fresh air from cracks between door and wall/ floors or any other openings only limited by its design static pressure. Plot this condition of dry and wet bulb temperatures on a psychrometric chart and find its enthalpy. Similarly, assign the desired enthalpy of room air based on the design room temperature.Heat load due to the air entrained into the room as a result of infiltration would thus be a product of mass flow rate of the air entrained and the enthalpy difference between indoor and outdoor condition.