Flashcards in *Bk 29- Smoke Removal Deck (37):
What are the two basic methods that are utilized to pressurize a contaminated area to enhance or direct the travel of contaminants to the exterior?
Natural and mechanical positive pressure ventilation
The current methods that are utilized to provide pressurized ventilation with portable blowers are ________ and _________ pressure ventilation.
Negative and positive
During negative pressure ventilation, the blower is placed inside or outside of the structure?
For positive pressure ventilation, is the blower placed inside or outside of the structure?
Compared to negative pressure ventilation, positive pressure ventilation is approximately how much more effective at removing contaminants from a building.
Positive pressure is most efficient when the exhaust opening (heat hole, window, door, etc.) is between ________ to ________ the size of the entrance opening
3/4 to 1 3/4
If a gasoline powered blower is being utilized and an exhaust odor is noticeable inside the building or area to be ventilated, this is an indicator of what?
That the exhaust opening is not big enough
Positive pressure has proven effective AGAINST winds (leeward to windward) of up to ______ mph
The effective implementation of positive pressure is dependent on what 5 things?
1. Entrance opening
2. Airflow between openings
3. Exhaust openings
A single blower should be positioned so the cone of pressurized air ________ covers the entrance opening
Tilting blowers at angles more than the manufacturer designed will result in what?
Lack of lubrication to the crankshaft
When blowers are placed in series, the first blower should be placed how far back from the opening?
When blowers are in series, the rear blower augments the front blower by what percent?
If two blowers of unequal CFM are utilized in the series position, how should they be lined up?
Larger blower up front, smaller blower behind
If the area in front of an entrance opening is limited to three or four feet (i.e., raised porch), place the smaller blower in the entrance opening and the larger blower how many feet back from the door?
What two ways can multiple blowers be positioned?
Series and parallel
Effective ventilation with blowers requires ___________ VENTILATION of contaminated areas within a building.
Removing screens on windows prior to using these openings for ventilation purposes will increase the efficiency of these openings by at least what percent?
Water powered blowers will produce considerably MORE or LESS CFM than the same size gasoline blowers?
_______ ppm of carbon monoxide inhaled for one hour is dangerous
_______ ppm of carbon monoxide inhaled for one hour will cause some appreciable effects
Concentrations of ________ ppm of carbon monoxide and over are fatal in less than one hour.
______ ppm of carbon monoxide can be inhaled for one hour without appreciable effects.
Positive pressure can easily reduce carbon monoxide concentrations of 1000 ppm to approximately _______ to ______ ppm.
A single 18" blower is adequate for an average single family dwelling that is how many square feet?
Depending on the type of fire, concentrates of carbon monoxide can easily be obtained in the range of ____ to ____ppm during overhaul operations.
500 to 1200ppm
Proper blower placement will assist in?
-Assist in search and rescue, extinguishment, overhaul, and other suppression operations
-Reduce or eliminate the numerous products of combustion.
-Reduce the interior temperature within a structure.
-Improve visibility for occupants and fire suppression personnel.
-Increased safety for occupants and fire suppression personnel.
-Reduce fire loss.
Interior blowers are not efficient in removing contaminants at the ____ of a room or building.
Positive pressure ventilation:
The size of the exhaust opening is dependent on what?
-Size of the entrance opening
-Capacity and number of blowers being utilized
Does temperature, humidity, and rain have any appreciable effect on positive pressure ventilation?
Positive pressure ventilation:
Multi-habitational occupancies (center halls) can be effectively ventilated by first pressurizing what area?
Appropriate stairways and hallways
Depending on the floor plan of a building and the location of the fire, opposing blowers can be effectively utilized to remove contaminants in a hallway and an apartment. Can blowers of unequal ratings be used in this situation?
Yes, Blowers of unequal ratings or equal ratings can be effectively utilized for this ventilation operation.
A multi-habitational occupancy that may need creative techniques for positive pressure ventilation are ____ story center hallway apartments.
To effectively use positive pressure ventilation in a high rise, position blowers(s) on the _____ (interior or exterior?) of the building and pressurize the opening to the ______ that is common to the contaminated floors
Use of water powered blowers should be considered in what type of structures?
-Metro rail tunnels
-High rise buildings
-Large underground parking structures
-Very large commercial buildings.
(should also be considered in rest homes, hospitals, and other types of structures where respiratory concerns should be considered)
Positive pressure does not have a tendency to accelerate or spread fire that may still be in the overhaul area. However, caution should be exercised when using positive pressure with _____ type fires.
smoldering type fires (i.e., mattress, overstuff, etc.)