Whenever I talk about humidity I have a strong sense that I don't really know what I'm talking about. I think this is normal, because humidity is not at all intuitive. I know that my glasses will steam up when I come into a warm room from the cold. But what goes on within walls and buildings is complicated and strange. When predicting which way the moisture will go, I end up just assuming it will go where we don't want it!
In today's video I attempt to explain. In doing so I realised I need to say a lot more about diffusion, and probably do a whole new lesson on summer humidity. I can also talk about traditional approaches to protect buildings against condensation.
Also I suggested that high humidity could increase the risk of spreading viruses. In fact low humidity can increase the risk of spreading viruses.
