Building Ventilation Flashcards
_____ is the process of intentionall bringing fresh air into a building
Ventilation
_____ happens when fresh air accidentally enters through openings or cracks in the building
Infiltration
How are rates for both infiltration and ventilation expressed?
in cubic feet per minute (cfm) or liters per second (L/s)
These are all examples of ________/______ ventilation
sustainable/green
cheap
can be effective
source dependant
Natural/Passive
These are all examples of ________/______ ventilation
Non-renewable
cost (initial and ongoing
can be effective
relies on available power
Mechanical/Active
this describes what effect?
Positive air pressure pushed air out of windows, seams, and cracks on the upper levels. Air rises to the upper levels as it warms and increases positve pressure near the top of the building. Negative pressure on lower levels encourages infiltration of col outdoor air through windows, doors, and openings
Stack Effect
____ side is positive pressure
Windward
____ side is negative pressure
Leeward
negative pressure means what?
There is suction
____ _____ is most efficent if there are windows on at least 2 sides of a room, preferably opposite each other
Cross Ventilation
____ _____ uses the stack effect, where heated air becomes less dense and tends to rise, displacing colder air downward
Convection Ventilation
______ _____ operable window area should be around 20% of the floor area, with windows split roughly evenly between windward and leeward walls
Comfort Ventilation
How can ceiling fans be used?
can be used to supplement natural/passive systems
these are all requirements for what type of ventilation?
40-50 cfm per linear ft of range
Should be as wide as stove +3-6”
20-24” max. above surface
wall mounts are better/safer
Updraft Ventilation Systems
An example of extreme ventilation would be?
Backdrafting
