{"id":131148,"date":"2025-08-26T10:15:39","date_gmt":"2025-08-26T08:15:39","guid":{"rendered":"https:\/\/www.velasolaris.com\/?post_type=handbuch&p=131148"},"modified":"2025-10-15T13:50:08","modified_gmt":"2025-10-15T11:50:08","slug":"cooling-load-estimation","status":"publish","type":"handbuch","link":"https:\/\/www.velasolaris.com\/en\/handbuch\/polysun-designer\/energy-demand-circuit\/thermal-consumers\/building\/cooling-load-estimation\/","title":{"rendered":"Dynamic Model: Cooling"},"content":{"rendered":"\n

Cooling Load Estimation Using Dynamic Building Simulation<\/h1>\n\n\n\n

Polysun includes a dynamic building simulation for estimating a building’s cooling load. This approach is based on the building’s physical parameters. It is particularly useful when the building’s actual cooling demand is unknown.<\/p>\n\n\n\n

The Role of Building Properties<\/strong><\/h2>\n\n\n\n

In order to estimate a cooling load based on building properties, these properties must first be defined. Polysun includes a catalogue of buildings with numerous standard types. These can be modified with specific inputs to match the properties of the building in question.<\/p>\n\n\n\n

\"Polysun's<\/figure>\n\n\n\n

Entering Building Dimensions for Cooling Load Calculation in Polysun<\/h2>\n\n\n\n

Once the building\u2019s properties, such as U-values, have been defined, the building\u2019s length, width, ceiling height, and number of floors need to be specified. This will determine its size.<\/p>\n\n\n\n

\"Building<\/figure>\n\n\n\n

To improve the accuracy of the cooling load estimation, additional information can be provided. This includes shading, natural ventilation, absences, target room temperature and unheated rooms.<\/p>\n\n\n\n

Once all parameters are entered, the cooling load is calculated by starting a simulation in Polysun. The results can be viewed and evaluated in various formats, including hourly values. See the example below for results with monthly resolution.<\/p>\n\n\n\n

\"Polysun<\/figure>\n\n\n\n

The underlying principles for cooling load calculations largely follow the same formulas as the dynamic heating model<\/a>. The dynamic cooling model accounts for the same influencing factors\u2014ventilation losses, infiltration losses, transmission losses, solar gains, and internal heat gains. Unlike the heating model, these factors are considered with a positive sign to reflect their contribution to cooling demand.<\/p>\n\n\n\n

\\(Q_{dem,cooling} = max(0, Q_{loss,vent,set} + Q_{loss,inf,set}+Q_{amb,set}+Q_{solar}+Q_{gain})\\)<\/p>\n\n\n\n

Energy Deficit<\/h2>\n\n\n\n

A warning, \u2018Building Cooling: Cooling capacity of the system is not met.\u2019 appears if the energy deficit is greater than 0 for longer than 7 hours.<\/p>\n\n\n\n

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