Could an intruder have opened the shutter and climbed in the window?

[Alice Purjorick]

So the air is flowing out of the bedroom and instead of going straight across into the lounge area or even into the main bedroom it turns left, left and right and goes into the kitchen? Is that reasonable?

This comes up every so often ; a bit like Orinoco Flow on the piped music in a hotel foyer.
All you need know:
Air moves from areas of high pressure to low pressure.
No building is completely sealed.
Force on door (F) = P x A; where A = door effective area which is variable open to closed (a bit of cos theta creeping in 'ere); P = pressure cause by movement of air dependent upon air velocity.
Effect of "chimney" (cooker hood/) from.
http://www.engineeringtoolbox.com/natural-draught-ventilation-d_122.html
Happy calculating to all and watch your units  .

oops I forgot this:
http://www.metoffice.gov.uk/learning/wind/what-causes-wind

[misty]

If a wind was blowing off the sea, which it is likely to do, which side of the building would it be likely to affect most ?

The predominant wind direction in PdL is NNW
http://wisuki.com/statistics/2500/praia-da-luz

[Anna]

If a wind was blowing off the sea, which it is likely to do, which side of the building would it be likely to affect most ?

Not sure about that jassi.
Would the wind from the sea not be lighter when the tide was going out?
However I will check out the wind conditions, unless someone has them at hand.

ETA
Found...
Wind heading mainly South...................To the children's bedroom?
 

[pegasus]

Is there any information to show which way the draught would have blown ? Was there a prevailing wind in any direction, for example?

Lagos 3rd May 2007 10pm. Wind 14.4km/h from WNW.
Wind direction matches KM's account perfectly.
It's the right direction to slam the door shut after she almost closed it.
And the right direction to blow the curtains in when she reopens the slammed door.
 

[jassi]

Thanks, Anna  & pegasus.

[Anna]

Thanks, Anna  & pegasus.

You are most welcome, jassi.
And thank you. Your question has assisted us in exploring other possibilities, re wind direction in relation to 5A.

[pegasus]

This comes up every so often ; a bit like Orinoco Flow on the piped music in a hotel foyer.
All you need know:
Air moves from areas of high pressure to low pressure.
No building is completely sealed.
Force on door (F) = P x A; where A = door effective area which is variable open to closed (a bit of cos theta creeping in 'ere); P = pressure cause by movement of air dependent upon air velocity.
Effect of "chimney" (cooker hood/) from.
http://www.engineeringtoolbox.com/natural-draught-ventilation-d_122.html
Happy calculating to all and watch your units  .

oops I forgot this:
http://www.metoffice.gov.uk/learning/wind/what-causes-wind

Thanks Alice. So moving the door to almost closed greatly reduces the opening, which increases the air velocity, which increases the pressure acting on the door. Also moving the door to almost closed increases the effective area of the door on which that increased pressure acts. So the two effects multiply each other proving that a door in a draught that doesn't move when it's wide open, will probably be slammed shut if you almost close it, which means that the witness is telling the truth.

[Alice Purjorick]

Just to lob a pebble into the pond; don't forget that buildings and their proximity to each other, locally influence wind direction and speeds by creating different wind paths and causing vortices.

[Anna]

If there is no open fireplace I would imagine there would be central heating of some kind.  Some residents were in occupation all year round and not just in the summer months.

Anna was right about some people attributing similar happenings to the paranormal and who is to say that is not the case as far as their experience is concerned.
However the more down to earth have come up with rational answers which you and others have already brought to the forum.
https://answers.yahoo.com/question/index?qid=20150608161309AAJ9Sqc
http://www.cyclechat.net/threads/why-does-the-wind-slam-doors.136658/
https://www.quora.com/Why-does-the-door-slam-when-a-window-is-open

Thank you Brietta
You posted some are helpful links.
Getting back to A/C and heating.......
In the photo below. What does it look like to the right of the basket weave, chair. Down low on the wall?

[stephen25000]

Just to lob a pebble into the pond; don't forget that buildings and their proximity to each other, locally influence wind direction and speeds by creating different wind paths and causing vortices.

It might be beneficial for posters to read up on laminar and turbulent flow .

[pegasus]

Thank you Brietta
You posted some are helpful links.
Getting back to A/C and heating.......
In the photo below. What does it look like to the right of the basket weave, chair. Down low on the wall?

Could be a vent for AC/heat but if so there must be at least one more in another room and where are the controls?

[Anna]

Could be a vent for AC/heat but if so there must be at least one more in another room and where are the controls?

I should think they were in the bedrooms at least. The controls on these small ones are usually on top or down on the left hand corner. We had one small one like that in Tangiers, Cyprus, and possibly Italy.

[Mr Gray]

Just to lob a pebble into the pond; don't forget that buildings and their proximity to each other, locally influence wind direction and speeds by creating different wind paths and causing vortices.

so it's impossible to calculate anything

[Alice Purjorick]

Thanks Alice. So moving the door to almost closed greatly reduces the opening, which increases the air velocity, which increases the pressure acting on the door. Also moving the door to almost closed increases the effective area of the door on which that increased pressure acts. So the two effects multiply each other proving that a door in a draught that doesn't move when it's wide open, will probably be slammed shut if you almost close it, which means that the witness is telling the truth.

What I am actually getting around to saying is unless you can replicate precisely all the conditions obtaining at the time and have all the dimensions of the appropriate features then mostly it is going to be guess work.
Someone with a knowledge of meteorology, fluid mechanics and mechanics will make a more informed guess that someone who hasn't.

In so far the door will tend to shut faster the larger the area of it that is exposed to the force the witness is correct. Hence my comment on cos theta.
For the door to "blow" closed there must be an area of high pressure one side of the door and low pressure on the other side QED. For a fixed flow at a fixed upstream pressure the velocity through a small aperture will be greater than the velocity through a large aperture however a smaller aperture will cause more resistance therefore restricting the flow if the upstream pressure remains constant; but just how much air do you calculate is being moved to balance the pressure?
Better stop here it will not tell us much.

Just stick to the high level stuff it is more informative.

[Brietta]

What I am actually getting around to saying is unless you can replicate precisely all the conditions obtaining at the time and have all the dimensions of the appropriate features then mostly it is going to be guess work.
Someone with a knowledge of meteorology, fluid mechanics and mechanics will make a more informed guess that someone who hasn't.

In so far the door will tend to shut faster the larger the area of it that is exposed to the force the witness is correct. Hence my comment on cos theta.
For the door to "blow" closed there must be an area of high pressure one side of the door and low pressure on the other side QED. For a fixed flow at a fixed upstream pressure the velocity through a small aperture will be greater than the velocity through a large aperture however a smaller aperture will cause more resistance therefore restricting the flow if the upstream pressure remains constant; but just how much air do you calculate is being moved to balance the pressure?
Better stop here it will not tell us much.

Just stick to the high level stuff it is more informative.

I doubt very much if the witness had any knowledge of the science behind slamming interior doors.  She described her experience exactly as it had happened ... and from the information posted by informed members ... we can see the description of the event fits the science.