Ventilation and Fan Placement

[D_W]

This is something that matthias wandel posted not long ago. I'm not a subscriber (like matthias, just don't generally get into the self-made powertool thing), but somehow, youtube knew I would find it interesting.

I don't want to tack this on just to the end of the other thread about ventilation because I'm sure that more than one person not reading that thread may find this helpful. Long story short, matthias actually measures air movement with fan placement in still air (outside - if there is a constant breeze, you can't fight it with a fan or you just cancel it out) and finds something I wouldn't have expected - that fans placed in windows tend to pull a lot of the air that they're moving from beside or in front of them (that is, they're pulling air from outside and pushing it back outside and only about half is originating from behind the fan).

The outcome is not intuitive.

 

[Rorschach]

Good to have my method backed up by research. I generally have it a little closer than he suggests so might try changing that, though I doubt I will be able to perceive a difference.

 

[Peter Sefton]

Another video with some thoughts on house cooling.

 

[dannyr]

Another video with some thoughts on house cooling.

We don't have too many very hot days in this country, (but then neither did Vancouver, and look at them this year, or 'Arctic Siberia' on fire). but anyway we have some and maybe can expect many more in future years

Much of UK housing stock was built 1820s-1920s with deep stone or brick walled cellars/basements beneath ground level - and these stay pretty cool most summer days (with no A/C or fans indoor temp in our stone+brick row/terrace house of this type is 26-30C in different rooms today, which is a hot day for here, but the cellar (including workshop) is 20C and less near its stone slab floor level).

So it would seem obvious to blow some of that cool air into at least one of the ground floor rooms - I'm thinking of a duct from near cellar floor level to a closable grate through the floor --- anyone do anything similar, or thoughts about this?? It'd be nice to have one cooler room without contributing too much to emissions.

 

[D_W]

you'll have some trouble duplicating the feat of the pacific northwest. East of the cascades and toward montana and in the lower canadian plains, hot and dry is common. My first thought when hearing of their high temperatures was whether or not they were getting an odd east wind (they were). 115F still isn't common, but over 100 on the plains where the wind was coming from is plenty common (the state record in MT is just above that 115F figure).

they're "lucky" there. they can see over 100F in the summer and -30C or lower in the winter (I think lower sask saw < -40C last year with really high winds).