deal wrote:...building a Yurt of kinds ...
So to help reduce the dust floating around inside the yurt I'm thinking of using a negative ion generator. I believe these charge the floating particles so that they stick to the surfaces within the structure rather than leaving them airborne....
2/ positive pressure... Evaporative cooler is a great way pumping air from outside to the inside. My concerne with this is how to filter the air adequately so your not just blowing in the dust from outside?
I'm thinking wrapping the outside in filter paper....
Just to be a little more forward than FIGJAM, and very clear:
Using the recommended pads for FIGJAM's DIY swamp-coolers means they are also a wetted particle filter - the incoming cooled air is also cleaned air. The pads are cleaned of dust by the pumped water flow, maintaining effective evaporation. If there's a lot of dust blowing around BRC that year, you might have to scoop some of that washed off dust out of the bottom of the swamp cooler sometime during the week. When the swamp-cooler is not running, as the pump isn't washing the pad with water, a strong wind may manage to blow some dusty air through to the inside. As long as you haven't left anything that can be ruined by some dust sitting out while you're away from your yurt (and I'm sure you won't...), the bit of dust that may get in won't matter, due to the next point...
Good thinking, but you don't need an ion generator. Dust hanging in the air gets exhausted when the air its hanging in is pushed out the exhaust vent by the swamp-cooler's incoming clean cool air. So while policing dust coming in on clothes, shoes & feet helps, you don't have to be radical about it.
The swamp-cooler's fan is pushing its cleaned cooled moist air into the shelter. You need
an exhaust vent for the shelter to allow the hot air inside the shelter to be pushed out by the incoming cool air. Without such a vent, the cool air resists being blown in, and that airflow is required for evaporative cooling to take place.
If the intake for the exhaust vent is located high up in the shelter, then you'll be exhausting the hottest air (remember hot air rises).
The exhaust vent can be closeable or one-way, to prevent hot air & dust entry when the swamp-cooler is not running (or driven in by wind). Some use a manual door that they put over or close when the swamp-cooler isn't running, and particularly when they're away from their shelter so a dust storm can't blow hot dusty air inside. A one-way vent is more convenient as it's one less thing to do and you don't have to think about it. Some use or make a light weight flap (clothes-drier vent type flap); others like using a furnace filter on the exhaust; others use an upside down “U” tube or a downward aimed 90 degree tube to discourage air blowing in, which also conveniently ignore rain.
Odd. No bears to watch in the dump. Oh well, lets go across the road & pick blueberries.
... but don't harm the red dragon that frequents the area from time to time. He and I have an agreement.