Bernoulli's principle

Bernoulli's principle states that in fluid flow, an increase in velocity occurs simultaneously with decrease in pressure.

Bernoulli's principle is about the behavior of a fluid – a gas or a liquid – as it flows through a pipe or tube. It states that when the pipe narrows or widens, the fluid pressure and speed vary. As the pipe narrows, the speed of the flow goes up and the pressure goes down. When the pipe widens, the fluid flow slows down and the fluid pressure goes up .

This principle is used in a carburetor to mix air with fuel. Air flows through the carburetor in a tube which contains a short section where the diameter narrows then widens again. This section is known as the 'Venturi'. As the air passes through the Venturi, the speed of the air flow increases, but the pressure inside the tube drops. This low pressure air passes over a small inlet which is connected to a gasoline – or petrol – fuel supply, drawing a small amount of fuel vapor into the air flow. The fuel/air mixture then goes to the engine.

Alternatives to HVAC

There are many alternatives to the HVAC system if we consider natural systems of ventilation and sunlight:
“thermal labyrinth”- concrete labyrinth below, air runs through at night and cools/warms depending upon season

Federation Square, Melbourne, Australia
•    Built in bridge condition over old railroad tracks
•    Used depth as “thermal battery”
•    Inhabited areas stay cool, highest reaches heat up, but air escapes through natural convection currents.
•    “double skin” create thermal blanket in winter
o    thermal chimney in summer
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“stack effect”:
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•    air is drawn upward and out, takes advantage of buoyancy of air
-created by elevator shaft
-revolving door creates a capacity for people to pass through without creating “stack effect” in tall buildings
-fireplace flu
Bernoulli’s principle:
•    Column of moving fluid→ accelerated airflow lowers pressue.

Venturi Effect:
If you narrow the opening, you lower the flow

Buildings learning from Termites
•    Porous walls harness wind that travels through to central chimney
•    Air flowing around mound pulls “stale” air out of internal chimney
•    Internal air current
•    In many climates, all cooling and comfort needs can be taken care of through the building envelope
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•    “shower tower” cools building- evaporative cooling towers