Pregunta 1
Pregunta
A zone is any area of a building for which indoor air temperature is controlled by a single thermostat (or other type of temperature controller).
Pregunta 2
Pregunta
Different rooms within a single zone (e.g., controlled by a single thermostat) and supplied with the same water temperature cannot be maintained at different temperatures by adjusting the flow rate through individual heat emitters.
Pregunta 3
Pregunta
If the heat emitters are connected in series , the system flow rate will pass through each heat emitter. If the heat emitters are connected in parallel, the flow rate through each heat emitter can be proportioned based on load using an equation.
Pregunta 4
Pregunta
Given the surface area of their bodies, hydraulic separators should be insulated to minimize heat loss to their surroundings.
Pregunta 5
Pregunta
Designers should think of hydraulic separation as a physical concept that must be accomplished as an all-or-nothing condition.
Pregunta 6
Pregunta
When a circulator with the flat curve is used, the differential pressure across the circulator changes dramatically as zone circuits turn on and off.
Pregunta 7
Pregunta
The electronically commutated motors and improved hydrodynamic design of current generation variable-speed pressure-regulated circulators provide wire-to-water efficiencies that are approximately double those of standard wet-rotor circulators with permanent split capacity.
Pregunta 8
Pregunta
If a fixed-speed circulator is selected, a differential pressure bypass valve should be installed to reduce the potential for flow noise when only one or two zones are active.
Pregunta 9
Pregunta
Over the last two decades, many heating professionals have come to recognize the failure of PEX and PEX-AL-PEX tubing as universal piping materials for residential and light commercial hydronic systems.
Pregunta 10
Pregunta
Primary/secondary (P/S) piping is the only way to achieve hydraulic separation between simultaneously operating circulators.
Pregunta 11
Pregunta
The time required to cool down or warm up a zone is significantly affected by the __________ of the heat emitter(s), and the building itself.
Respuesta
-
thermal envelope
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thermal mass
-
ambient temperature
-
setpoint temperature
Pregunta 12
Pregunta
All hydronic systems, regardless of how they are designed or installed, attempt to simultaneously stabilize at two unique operating conditions called thermal equilibrium and __________ equilibrium.
Respuesta
-
spatial
-
hydraulic
-
zoning
-
R-value
Pregunta 13
Pregunta
In a technique known as __________, the designer repeatedly analyzes both the hydraulic and thermal performance of a system using "candidate" hardware options and operating conditions, until a combination is found that yields acceptable heat distribution.
Respuesta
-
trial and error
-
selective pairing
-
elimination
-
iteration
Pregunta 14
Pregunta
Ideally, each circulator in a system will establish a differential pressure and flow rates that is unaffected by the presence of another operating circulator within the system. This very desirable condition is called __________.
Respuesta
-
hydraulic equilibrium
-
hydraulic separation
-
the pump curve
-
ideal circulation
Pregunta 15
Pregunta
The degree to which two operating circulators interact with each other depends on the head loss of the piping path they have in common. This piping path is called the __________ piping.
Respuesta
-
circulatory
-
serpentine
-
head loss
-
common
Pregunta 16
Pregunta
The purpose of differential pressure bypass valves (DPBV) is to _________ the differential pressure imposed on the distribution system by a fixed-speed circulator as the system flow rate decreases due to closing zone valves.
Respuesta
-
accelerate
-
equalize
-
limit
-
increase
Pregunta 17
Pregunta
One approach that takes advantage of the flexibility of PEX or PEX-AL-PEX tubing is called a __________ distribution system.
Respuesta
-
hydroplastic
-
home run
-
hybrid
-
green
Pregunta 18
Pregunta
The closely spaced tees connecting a secondary circuit to the primary circuit are __________ when air is being purged from the system.
Respuesta
-
counterproductive
-
instrumental
-
essential
-
irrelevant
Pregunta 19
Pregunta
The concept of __________ provides a means by which the electrical energy consumption of a distribution system, per unit of heat delivery capacity, can be calculated and compared.
Respuesta
-
hydraulic separation
-
hydraulic equilibrium
-
thermal envelope
-
distribution efficiency
Pregunta 20
Pregunta
The diverse loads served by many modern residential and light commercial systems often dictate that the distribution system contains elements from __________ of the basic distribution systems discussed in this chapter.
Respuesta
-
one specific
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two or more
-
at least three
-
possibly none