ᐅ Why is shading especially important in newly constructed houses?

Created on: 29 Aug 2016 13:33
G
Grym
It is often argued that shading is especially important in new builds to prevent overheating in summer. But why is that exactly?

The insulation in a new building works both ways. Whether it’s cold or heat, the house takes much longer to adopt the outside temperature compared to an older house with poorer insulation.

Now, regarding the windows themselves. Shouldn’t solar energy pass through a less effective double-glazed window faster than through a modern triple-glazed window?

Why do many say that shading is PARTICULARLY important in new builds during summer? I would rather think the opposite: a new build is better insulated against heat from outside. Triple-glazed windows with a low U-value keep heat out better than old double-glazed windows.
K
Knallkörper
29 Aug 2016 22:23
Bieber0815 schrieb:
Thermal insulation in terms of the U-value practically only accounts for convective heat transfer

No, conductive heat transfer.
K
Knallkörper
29 Aug 2016 22:27
Mycraft schrieb:
You can look at it from every angle... The fact is: Houses nowadays are built to keep the heat inside... all the time...

Heat transfer is not one-way, and the principles of physics have not been reinvented "nowadays." The heat stays inside longer today, but it also remains outside longer (if it weren't for the large windows... See post by Bieber0815). However, you don’t simply wait for the heat accumulated during the day to escape through conduction in the walls; instead, you ventilate. As mentioned, the energy transfer through ventilation is many times greater, and during the day, you benefit from the slower warming due to the low U-value of the building envelope.
RobsonMKK29 Aug 2016 22:40
Did you air out the house over the weekend? If there is no wind and the temperature inside and outside is the same, then Sebastian is right... Practical experience beats textbooks.
L
Legurit
29 Aug 2016 22:45
If practical experience cannot be explained by the textbook, it means either the textbook was not understood, or a new one needs to be written.
RobsonMKK29 Aug 2016 22:57
Not really. But if there's no breeze outside, there won't be any air exchange.
K
Knallkörper
29 Aug 2016 22:57
RobsonMKK schrieb:
Did you ventilate over the weekend? If there is no wind and the indoor and outdoor temperatures are the same, then Sebastian is right... Practical experience beats theory

No, because when the indoor and outdoor temperatures are equal, no heat energy flows through the facade, regardless of the insulation.