Hydronics- Chapter 3

What is the maximum design pressure for a low temperature boiler (ASME)? a. 160 psig b. 180 psig c. 210 psig d. 250 psig

A. 160 psig

______________________ and mounting method are the two main factors in selecting a low-water cut-off.

Boiler Pressure

______________________ is the reverse of boiling.

Condensing

Select the correct valve that would be used to regulate the rate of HTF flow in a piping system. a. check valve b. isolation valve c. Gate valve d. Balancing Valve

D. Balancing Valve

True or False: A circulating pump cannot be the main pump in a hydronic system.

False

True or False: A compression stroke is the movement of a piston in a cylinder that causes the volume of the cylinder to increase, which rapidly decreases the pressure.

False

True or False: A heat pump can operate only in heating mode.

False

True or False: A low-water cut-off is a device that is designed to monitor the water level in a boiler and to signal the boiler burner to shut down if the water level rises above the safe level of the boiler.

False

True or False: A reduced pressure principle backflow prevention assembly is a backflow preventer consisting of three independently acting internally spring-loaded check valves, a differential pressure-relief valve, three properly located test cocks, and three isolation valves.

False

True or False: In a system with a natural-draft boiler, the amount of natural draft produced decreases with the height of the flue.

False

True or False: Refrigerants typically have a high boiling point.

False

True or False: Single-wall heat exchangers are less efficient than double-wall heat exchangers of equal size.

False

True or False: The steel boiler ranges from 50,000 Btuh to a maximum of 100,000 Btuh.

False

A pressure vessel is a tank or container that operates at a(n) ______________________ greater than atmospheric pressure.

Pressure

______________________ compressors compress refrigerant vapor by moving a piston up and down inside of a cylinder.

Reciprocating

Whenever the temperature in a boiler is above 212*F and the ______________________ discharges, the sudden pressure drop causes the higher temperature water to flash to steam.

Relief valve

True or False: A forced-draft cooling tower is a cooling tower in which fans are located in the airstream, typically at the top of the tower, in order to force the ambient air through.

True

True or False: A pressure- reducing valve must be installed with the arrow on the body pointing in the direction of flow.

True

True or False: A relief valve is an automatic pressure relieving device actuated by the static pressure upstream of the valve, and it opens further with the increase in pressure over the opening pressure.

True

True or False: As evaporator-to-condensor pressure differential increases, compressor work heat decreases in relation to evaporator cooling ability.

True

True or False: Fuel oil burners atomize fuel oil to increase contact with combustion air for maximum combustion efficiency.

True

True or False: Heat absorption occurs at a low temperature and pressure, and is known as the low pressure side of a refrigeration system.

True

True or False: In a plate heat exchanger, heat passes very easily through the thin wall separating the two media from each other.

True

True or False: Tankless boilers heat HTF as it flows through the heat exchanger.

True

True or False: The most commonly used cooling terminal unit uses a fan to blow the room air over a coil through which chilled HTF is circulated.

True

True or False: The most commonly used heat source in hydronic systems is the boiler, which has many forms.

True

True or False: The most frequent cause of nonperformance in heat exchangers is the improper venting and fouling.

True

An output rating is the total amount of heat a boiler will produce in _________________? a. 1 hour b. 30 minutes c. 24 hours d. 1 year

a. 1 hour

What is the device that can be used to both heat and cool an area? a. Heat pump b. chiller c. boiler d. cooling tower

a. Heat pump

What type of flow has better heat transfer in a coil? a. Parallel flow b. Couterflow c. Upward flow d. Downward flow

a. Parallel flow

A(n) _____________ is a high-volume hydronic air conditioning device that cools circulating HTF for terminal unit use. a. chiller b. compression tank c. expansion tank d. water feeder

a. chiller

A __________________ is a device used to reject heat from the water circulated through a building's water-loop system or chiller condenser. a. cooling tower b. magnetic bearing c. compressor d. space cooler

a. cooling tower

The boiler is considered ____________ if the combustion chamber is mounted below the HTF. a. dry-based b. wet-based c. dry leg d. wet leg

a. dry-based

In a compression refrigeration system, where is the heat absorbed? a. evaporator b. compressor c. condenser d. metering device

a. evaporator

A ___________ utilizes a paddle to sense fluid flow and physically close and electrical circuit, allowing power to the boiler burner. a. flow switch b. makeup water line c. pressure-reducing valve d. boiler blowdown valve

a. flow switch

__________________ draft is mechanical draft from air pulled through the boiler combustion chamber with fans located in the breeching. a. induced b. noncondensing c. condensing d. forced

a. induced

A(n) _________ heat exchanger is a heat exchanger that is located in a thermal storage tank and allows the transfer of heat from one HTF to the other without permitting the two liquids to mix. a. internal b. single-wall c. double-wall d. external

a. internal

As a vapor is compressed in a compression refrigeration system what happens to the refrigerant? a. temperature increases b. converts to a liquid c. condenses d. pressure decreases

a. temperature increases

The ______________________ is the temperature difference between cooling water leaving a cooling tower and the wet-bulb temperature of air entering the tower.

approach

The atmospheric vent in a backflow preventer is required to open under a backflow pressure condition when the supply pressure is no less than _______% of the downstream pressure. a. 5 b. 20 c. 60 d. 75

b. 20

The average low pressure water boiler is constructed for a maximum working pressure of __________ psig. a. 10 b. 30 c. 50 d. 70

b. 30

What device is used to protect a potable water system from cross connections? a. circuit setter b. backflow preventer c. pressure relief valve d. isolation valves

b. backflow preventer

The ________________ is the part of a mechanical refrigerating system that receives the refrigerant vapor at low pressure and compresses it into a lower volume at a higher pressure. a. condenser b. compressor c. evaporator d. cooling tower

b. compressor

Name the four main components of a chiller system: a. pump, air tank, HTF, pipe, boiler b. compressor, condenser, evaporator, refrigerant c. piping, refrigerant, compression tank, pump, terminal unit d. radiant slab, compressor, condenser, piping

b. compressor, condenser, evaporator, refrigerant

Which type of boiler uses microprocessor-controlled combustion which automatically adjusts air-fuel mixture? a. cast iron b. condensing c. scotch marine d. steel tube

b. condensing

_________________ boilers are normally water-tube boilers that use a configuration of finned tubes with headers as the heat exchanger. a. stainless steel b. copper c. aluminum d. cast-iron

b. copper

A condensing boiler is a boiler where the heat exchangers are designed to extract ____________ heat from the water vapor found in hot combustion gases before the gases enter the flue. a. specific b. latent c. sensible d. vaporized

b. latent

When a heat pump is in cooling mode, the outdoor device is ________________? a. the evaporator b. the condenser c. the 4 way valve d. the compressor

b. the condenser

The ______________________ system is that part of a boiler that regulates the flow of air to and from the boiler fuel burner.

boiler draft

A(n) ______________________ plate heat exchanger is sometimes referred to as a "honeycomb" or "turboseal-type" plate exchanger.

brazed

What does the ASME Boiler Pressure Vessel Code require if the output of a boiler is 400,000 Btuh or more? a. makeup water b. chemical pot feeder c. LWCO d. wet rotor pump

c. LWCO

A(n) _________ is a device that controls the starting, stopping, and firing rate of a hot water boiler burner by measuring the temperature of the water in the boiler. a. temperature reset control b. relief valve c. aquastat d. boiler fitting

c. aquastat

Fuel oil burners _____________ fuel oil to increase contact with combustion air for maximum efficiency. a. stabilize b. mix c. atomize d. heat

c. atomize

Which type of device is attached to the boiler to assist in the management of air in the hydronic system? a. aquastat b. relief valve c. boiler fitting d. LWCO

c. boiler fitting

Flue temperatures are required to be at least 250*F to prevent ___________ in the flue. a. compression b. evaporation c. condensation d. suction

c. condensation

The ___________________ is the reservoir located above a cooling tower to hold heated water prior to its flow through the fill. a. collection basin b. compression tank c. distribution basin d. range

c. distribution basin

A compression tank is a thermal expansion and air capture component that performs ________ important functions in a hydronic heating system. a. two b. three c. four d. five

c. four

A condenser acts as a type of ____________? a. compressor b. cooling tower c. heat exchanger d. balancing fitting

c. heat exchanger

A ___________ cooling tower is a cooling tower in which the water and ambient air are introduced at the top of the tower and flow downward through the fill. a. crossflow c. parallel-flow c. direct flow d. counterflow

c. parallel-flow

Which device protects the boiler from pressures above maximum design pressure? a. check valve b. balancing valve c. relief valve d. gate valve

c. relief valve

The _____________ compressor consists of a motor-drive shaft that turns a plate with a spiral of metal on it. a. rotary b. magnetic c. scroll d. reciprocating

c. scroll

The purpose of renewable, sacrificial anodes present on some exchangers is to provide ______________________ in order to inhibit electrolytic corrosion.

cathodic protection

The ______________________ on any closed piping circuit will dictate, by its location, the system pressure changes that will occur when the pump starts.

compression tank

The ______________________ pumps the vaporized refrigerant away from the evaporator and discharges it at a higher pressure and temperature into the condenser.

compressor

According to manufacturers, the operating efficiency ______________________ boilers can be as high as 98%.

condensing

Low- pressure boilers have specific pressure and temperature limits; what is the maximum pressure temperature limit for these boilers (ASME)? a. 25 psig steam, 140 psig water A 212*F b. 50 psig steam, 160 psig water @ 250*F c. 20 psig steam, 130 psig water @ 180*F d. 15 psig steam, 160 psig water @ 250*F

d. 15 psig steam, 160 psig water @ 250*F

The hydronic cooling cycle is composed of ________________ separate and distinct cycles that create the complete system. a. 2 b. 3 c. 4 d. 5

d. 5

Low-pressure boilers are classified by _________________? a. 15 psig steam abd 160 psig water b. 60 MBH and below c. 35-100 MBH d. Type of construction

d. Type of construction

Which boiler has the highest output rating? a. cast iron b. scotch marine c. condensing d. electric

d. electric

The hydronic cooling cycle is composed of ________ separate and distinct cycles that create the complete hydronic cooling system. a. two b. three c. four d. five

d. five

A(n) ____________ is a mechanical compression refrigeration system that reverses the flow of refrigerant through a system to transfer heat from one area to another. a. electric resistance heater b. solar water heater c. boiler d. heat pump

d. heat pump

Select the best description of a LWCO. a. Low water circulator b. little water cut off c. less water control operator d. low water cut off

d. low water cut off

A ______________ cooling system uses water's cooling capacity a single time. a. reciprocating b. dry c. wet d. once-through

d. once-through

A(n) ________ burner consists of a forced air fan that is used to bring air under pressure into close contact with fuel. a. electric b. free-air c. gas d. power

d. power

Select the devices which would be included in a make-up water system. a. pressure relief, backflow, isolation b. balancing valve, backflow, isolation c. flow control, backflow, isolation d. pressure reducing valve, backflow, isolation

d. pressure reducing valve, backflow, isolation

A ___________ heat exchanger is an external tube-type heat exchanger that consists of a large pressure vessel with multiple tubes that run through it. a. cathodic b. brazed c. plate d. shell-and-tube

d. shell-and-tube

A(n) ______________________ uses a series of copper rods enclosed in waterproof tubes surrounded by water to provide heating by electricity.

immersion heater

A(n) ______________________ is the amount of heat produced by a boiler as fuel is burned and is expressed in British thermal units per hour (Btuh).

input rating

The ______________________ to a boiler is the cold water supply to the boiler that is used for boiler fitting.

makeup water

Backflow prevention involves the selection and installation of an approved backflow preventer designed to prevent backflow into a(n) ______________________.

potable/drinking water

A(n) ______________________ contains either a bladder or a diaphragm to separate the air charge contained in the tank from the system HTF.

pre charged expansion tank

A(n) ______________________ boiler, a variation of the fire-tube boiler, utilizes a central fluid backed by cylindrical combustion chamber surrounded by fire tubes accommodating two or more flue gas passes.

scotch marine

A(n) ______________________- vane compressor is a type of rotary compressor that has a rotor to which the vanes are attached.

stationary

Solar water heating utilizes the portion of the solar radiation spectrum referred to as ______________________ to create heat energy.

sunlight

Air control boiler fittings are selected on the basis of the ______________________ supply main size.

trunk

A(n) ______________________ cooling tower is a cooling tower with open water loops, allowing direct contact between circulating water and outside air.

wet