A complete analysis of the heat, air and moisture transfer on building performance

Abstract

The simulation of combined heat, air and moisture (HAM) is important to predict the indoor air quality and thermal comfort. Moreover, inappropriate levels of indoor humidity and temperature can contribute to a high movement of water vapor through the building walls, causing deterioration and reduction of the thermal insulation which leads to higher energy demand. The simulation of the buildings behavior can help to optimize the design of new or existing building, help better control the HVAC system and therefore results in energy efficient buildings. In this work, an in-house modular object-oriented tool (NEST) for the multiphysics simulation of buildings is presented. The whole building is modeled as a collection of basic elements (e.g., walls, rooms, openings, occupancy, HVAC system, solar radiation distributor, etc.). These elements can be modeled using different physical models and scales. A combined heat, air and moisture transfer model for the building envelopes and rooms have been implemented and validated with different benchmark cases. The in-house simulation tool has been used for the simulation of hygrothermal behavior of rooms inside different public buildings (residential apartments, hospital rooms, universities and school plants). The simulations allowed as the analysis of the humidity effect on thermal comfort and energy performance of the rooms.