U-24: Auxiliary Building Systems Flashcards
Two most common types of occupancy sensors:
Infrared and ultrasonic
Occupancy sensors are what kind of switches?
Automatic
Lumens per watt is the measurement of what efficiency?
Lamps
A lighting unit including the lamp, a voltage controlling device or ballast and the means of light control (reflector and refractor) is what?
Luminaire
In large building what percent of the electrical load is lighting usually?
60
Employing occupancy sensors can reduce lighting costs by?
20-60%
Motion sensor that responds to motion
Ultrasonic
What is the function of the luminaire in terms of a lamp?
Direct or control the light produced
Motion detector that responds to heat
Infrared
Types of luminaries consist of four kinds:
Recessed troffers, ceiling mount wraparounds, open reflectors and structural lighting
What does PVB and AVB stand for?
Pressure vacuum breaker
Atmospheric vacuum breaker
It protects against excessively high water temperatures?
Fusible plug
What are two ways water can be distributed throughout a building?
Upfeed or downfeed systems
Pressure in a building plumbing system should not drop below what pressure?
175 kPa
Flashing of water into steam when faucets are open can be prevented by?
Temperature relief devices
Large system that forces large amounts of water to be wasted before hot water is available
Non circulating system
Back flows prevention consisting of two independently acting check valves with an automatic pressure differential valve located between the check valve. What is this method called?
Reduced pressure principle device
Instaneous water heater is known as a?
Tankless water heater
A pipe which usually prevents the accumulation of ground water around the buildings foundations?
footing drain
Materials often used for indoor sanitary drainage systems are:
Cast iron, galvanized steel and copper
How often should a water storage heater be drained, cleaned and inspected?
Annually
Branch lines should not meet at angle greater than?
45 degrees
Drawing out of sealing liquids in traps in a drainage system is due to?
Negative pressure
When externally located the trap should be within how many millimeters from the fixture?
610 mm
How many basic styles of flushometers are there?
2
How many water does a toilet tank flushometer deliver every 10 seconds?
13.7 L
How many valves are there on a toilet flush tank?
2
Horizontal branch lines must have a adequate slope to maintain a minimum flow velocity of?
0.6 m/s
How can waste gases be pushed back into the building through traps?
Positive pressure in the drainage system
A pipe used to reduce hydrostatic water pressure on the walls below ground level is called a?
Footing drain
What is the purpose of providing an air fusion in a water system?
Prevent water hammer
