All under the summer sun gets hot and this is particularly so of buildings as they also store energy, by absorption, to the extent that during the evening they remain quite warm due to this retention aspect.
Insulation for instance, great for resisting heat but not so great for releasing it and in fact is one of the reasons why homes remain warmer when the sun goes down.
The temperature of an evening can be quite cool outside and yet the interior remains quite warm and this is simply because the heat is unable to escape.
In order for hot air to escape, vertically being the most efficient, a volume air needs to replace that which is moving out, more so when the house is double storey. The lower level which is cooler during the day, stays warmer longer of an evening.
So there you are, laying in bed of a summer’s evening, sweltering and wanting to know why the cool air outside isn’t coming into the room.
You have a house full of energy with nowhere to go….and no, it’s not going to go out the windows because natural energy wants to move vertically, upwards, towards the sky.
Cool air, on the other hand, likes to move laterally, sideways…cool air is heavier through density and it takes more coercion to get it to move in any direction and in your case through the window into the bedroom.
Displacement!….you need a means of natural displacement….for air to come in air has to go out first.
There’s a reason as to why you can’t blow air into a bottle
Now if you could only take the roof off for an hour or so…you can’t.. ..so you do the next best thing, …..and take your pillow outside.
Punch a hole in the ceiling…and the roof and you have a means of escape for the energy trapped in the bedroom….called natural ventilation…referred to as the evening purge cycle
You sleep better and when refreshed, you and your family are off to a better day because of it, and at no extra cost because it occurs…. naturally.
There are ventilation products that help you achieve this however be aware that products with moveable parts of plastic have a short life span and when they break down, they do so at a very inconvenient time.
The cooler the house is entering the following day, the more comfortable it is because it doesn’t carry the heat retention of the previous day into the next.