It occurred to me recently, that with all the talk of global warming, and energy, bug migration to the UK and hotter summers and colder winters,we might want to take a look at the way a lot of properties walls and other external surfaces actually work.
By this I mean the way we plan for condensation to occur on the external side of the free cavity, during the winter, we can clearly see from my quick sketch the way a lot of cavity walls work, condensation occurs at the cold side of the cavity and drains away, we try to slow it down with vapour barriers but they leak and inevitably the condensation forms, but the wall is capable of dealing with it. same goes for several other different types of wall construction, timber frame, render and solid walls, and lets not forget pitched and flat roofs.
But consider this, if the summers get hotter and longer and humidity rises a little, the condensation point is going to move, inwards, not helped by our natural inclination to chill the internal space.
The short summers and climate we see now, does not let this happen currently, the walls cope, but condensation is going to form on parts of the construction, currently not designed to cope with it, mould will form and we will see health problems.
So todays problem and CPD research is to look at this problem and see what can be done, you might like to split this into the various types of construction:
of this list Cavity wall and timber frame worry me, they will just fail.
My next step is to see what the European construction looks like, they must see this happening, how does Canada cope, I have been in Toronto in the summer with very high temps , humidity. I once worked on a Canadian system called R2000, I and going to look into this to see what they did, and how they cope with this temp and humidity, don’t forget their winters are a complete reversal, low temp and dam cold.
Of course, the answer might just lie in the use of sensors within the wall and devises like the nest, this could easily tell when things are getting out of sink and deal with it, by altering internal temps and humidity to move the condensation point back to a point where that particular construction can deal with it.
This leads to all sorts of question, sensors that last the life time of the building, and here I am looking at background scatter technology to provide the energy the sensor might need, Nest devises that can not only read the output but see incoming weather so as not to knee jerk react to immediate temp and humidity changes.