Principles of passive design: Thermal Bridges
A thermal bridge ‘free’ design is one of the 5 fundamental principles of Passive House design and construction. For this occasion, our collaborator Alejandro Davila, a consultant at Eosis, explains what this topic implies.
What is a thermal bridge?
Well just like its in the name, a thermal bridge is literally a non-wanted connection from the outside to the inside.
This could either be heat or cold but to put it in better words the definition given by the Passive House Institute is that thermal bridges are thermally weak points or interruptions in the building envelope. More heat is lost here than in areas without interruptions.
The Building Research Establishment states how typically a thermal bridge happens where there is either a break in the insulation, less insulation or the insulation is penetrated by an element with a higher thermal conductivity.
There are two types of thermal bridges: linear and point thermal bridges. This really depends on the materials that are used during construction and how much conductivity the materials have.
Why are thermal bridges important?
Well, we are going to talk about the two most important things.
First of all, we are talking about a break in the insulation of a building (let’s think of it as a hole in your jacket, because of that hole you will get cold in that spot if is freezing outside) which obviously worsens the building’s overall thermal performance.
Secondly, thermal bridges affect directly on the surface temperature of a building. This is bad because the surface temperature factor is also calculated as part of the assessment procedure and is used to assess the risk of mold growth, which can have significant health implications.
This is really important in humid places because molds produce allergens, irritants, and even toxic substances. So if you see mold and start having symptoms like sneezing, stuffy nose, cough, Itchy eyes, nose and throat, or even asthma go see a doctor and treat that mold!