Förbättringsåtgärder för termisk komfort i ett 70-tals lamellhus i Gävle

Sammanfattning

In 1964, the then Swedish government decided that one million new homes would be erected within a decade to tackle the then housing shortage. This decision was characterized as the “million program”. Just over five decades later, many of the million program's buildings needrenovation. After many years of use, structural engineering measures are required to satisfytoday's standards regarding thermal comfort. One or more deficiencies mentioned about the buildings of the million programs can have a direct or indirect impact on the thermal comfort. Poor or excessive ventilation, windows that are leaky or have high heat permeability and poor insulation are factors that can adversely affect thermal comfort. Thermal comfort is a key issue today as it affects us all. According to The Public Health Agency of Sweden, thermal comfort can have several different effects on our health, where too high temperature can result in headaches, nausea, and fatigue, while too cold indoor climate can lead to more dramatic health effects such as lung-related diseases, vascular diseases and affected blood pressure. We Swedes spend about 90 % of our lives indoors.In this case study, a two-story slat was examined on Regnbågsgatan in Gävle with the aim of identifying deficiencies and developing a model in IDA-ICE and then investigating various improvement measures. Data to produce the model was collected through an ocular inspection with IR thermography for identification of thermal bridges, drawings, user data from Sveby and data from the Gavlegårdarna which were then supplemented with a literature study. The model was created with four different programs: Revit, where a basic geometric model was created, Simplebim for validation of model before IDA-ICE, COMSOL Multiphysics for modeling thermal bridges and finally IDA-ICE for energy and climate simulations.Potential improvement measures were discovered through literature study and analysis of deficiencies that could be identified in simulation of current cases for the slat building. The measures were carried out by changing different input data for the different components of the slat housing in the IDA-ICE program. A survey study was conducted to investigate how users experienced the thermal climate; however, the outcome of this study did not lead to anything as there were too few respondents.Deficiencies that could be detected during the first simulation were that rooms located at the gables had poor thermal comfort because the gables were not sufficiently insulated. Rooms with the worst thermal comfort could be identified at the northern end and a trend that floor 2 had poorer thermal comfort compared to floor 1. A combination of additional insulation of the gables, replacement of windows and balcony doors to those with a lower U-value, as well as a temperature-controlled FTX system had the best effect on thermal comfort. After this action, the building meets the requirement for bronze in terms of the thermal climate summer and winter according to Sweden Green Building Council.