Week 2: Hydronics Quiz

A ____ is a device for converting low-temperature heat into higher temperature heat. Select one: a. radiating unit b. heat pump c. flue gasket d. thermal converter

A

A flow restriction or stoppage in the ____ can lead to rapid formation of ice crystals on the cold heat exchanger surfaces separating the water and refrigerant. Select one: a. evaporator b. storage tank c. water source d. closed-loop

A

Boilers biult exlusively for hydronic heating systems no loger require a(n) Select one: a. internal steam chest b. fire box c. water jacket d. flue gas passage

A

Every hydronic heating system attempts to establish operating conditions that allow the distribution system to current rate of heat output from the heat source. This state is known as ____. Select one: a. thermal equilibrium b. reverse return flow c. radiant heat output d. hydraulic channeling

A

Hydronic system designers often need to know the ____ of heat transfer to or from a stream of water flowing through a device such as a heat source or heat emitter. Select one: a. rate b. thermal mass c. exact volume d. temperature

A

The amount of air that can exist in solution with water is strongly dependent on the water's temperature. As water is heated, its ability to hold air in solution ____. Select one: a. rapidly decreases b. is viscosity dependent c. rapidly increases d. remains constant

A

A typical finned-tube baseboard convector.consists of a sheet metal enclosure containing a ____ tube fitted with aluminum fins. Select one: a. PEX b. copper c. cast iron d. stainless steel

B

Analysis of combustion processes reveals that significant amounts of heat can be recaptured from the exhaust stream if the water vapor it contains can be ____. Select one: a. replenished regularly b. condensed within the boiler c. minimized d. expelled from the system

B

Back-flow preventers are installed inthe boiler feed piping to avoid Select one: a. expansion tank drainage b. contamination of the potable water supply c. the overheating of a single heating zone d. water hammer in the piping

B

Baseboard radiation is usually installed where? Select one: a. Under the floor b. Along the outside walls of the building c. In recessed spaces under the windows d. Along the interior partitions

B

In hydronic system piping, the air eliminator is installed on the Select one: a. return piping before the circulator b. supply piping near the boiler c. end of the supply main d. top floor radiator furthest from the boiler

B

Incompressibility implies that liquids can exert tremendous pressure in any type of filled and closed container when they ____ due to heating. Select one: a. dissolve b. expand c. contract d. vaporize

B

Operating panel radiators at ____ water temperatures increases the percentage of radiant versus convective heat output from the panel. Select one: a. ambient b. lower c. thermally equalized d. higher

B

The best location for the installation of the pressure reducing feed valve connection is Select one: a. in a tee on the return line near the circulator b. in a tee in the line between the air eliminator and the expansion tank c. at the bottom of the boiler where the return main is connected d. in a tee on the supply main

B

The combination of metal and water weight gives cast-iron boilers the ability to absorb a significant amount of heat. Such boilers are said to have a high ____. Select one: a. life cycle b. thermal mass c. size d. efficiency factor

B

The head loss of radiant baseboard can be determined by considering each baseboard to be a tubing circuit approximately ____ as long as the baseboard extrusion. Select one: a. three times b. twice c. half d. equally

B

When a quantity of liquid water is put under pressure, there is ____ change in its volume. Select one: a. a formulaic b. very little c. a corresponding d. a significant

B

A two-pipe forced hot water system relief valve opens when the oil burner runs. This can be caused by which of the following? Select one: a. A defective air eliminator b. A hot water control set improperly c. An expansion tank that is full of water d. A faulty circulator

C

Boilers with low thermal mass tend to have ____ cycle efficiencies due to lesser amounts of heat remaining in the boiler following burner shutdown. Select one: a. unpredictable b. lower c. higher d. dependable

C

If the material changes phase while absorbing heat, its temperature does not change. The heat absorbed in such a process is called ____ heat. Select one: a. radiant b. sensible c. latent d. ambient

C

In solar anti-freeze based combisystems, the outside heat dump provides a way for the system to shed excess heat. It is activated if the temperature of the thermal storage tank reaches a ____ upper limit. Select one: a. local fire code b. manufacturer recommended c. user-set d. DOE enforced

C

Increasing the fluid flow rate through the coil will ____ increase the heating capacity of the fan-coil. Select one: a. never b. greatly c. marginally d. unpredictably

C

It is vital that the solar collectors and all exposed piping in a drain-back system be pitched a minimum of ____ toward the storage tank to allow complete drainage. Select one: a. 1/2 in./ft. b. 1/16 in./ft. c. 1/4 in./ft. d. 1/8 in./ft.

C

Most cast-iron sectional boilers are limited to use in ____ hydronic systems. Select one: a. packaged b. "bare-bones" c. closed-loop d. distributed

C

One type of boiler design surrounds the combustion chamber with a water-filled heat exchanger. This arrangement is called a ____ boiler. Select one: a. hydraulic b. condensation c. wet-base d. steam

C

One way that heat loss of bare copper tube can be evaluated is when the length of the copper tube in feet divided by the flow rate in gallons per minute exceeds ____ ft./gpm, there will be a greater temperature drop along the tube from inlet to outlet. Select one: a. 10 b. 15 c. 20 d. 5

C

The ____ pressure of a liquid is the minimum pressure that must be applied at the liquid's surface to prevent it from boiling. Select one: a. mean b. surface c. vapor d. systemic

C

The heat absorbed or released by a material while it remains in a single phase is called ____ heat. Select one: a. latent b. radiant c. sensible d. ambient

C

The heat output of finned-tube baseboard is expressed in Btu/hr./ft. of active element length. The active length of the element is the length of pipe ____. Select one: a. nearest the riser's centerline b. under a source of downward drafts c. covered with fins d. in the entire assembly

C

The single-pipe loop hydronic system was made possible because of Select one: a. diaphragm type expansion tanks b. mono-flow tees c. baseboard radiators d. air eliminators

C

The viscosity of a fluid is an indicator of its resistance to ____. Select one: a. displacement b. heat c. flow d. combining

C

To prevent corrosion, steel panel radiators should only be used in ____ systems. Select one: a. parallel b. open-loop c. closed-loop d. hydraulically calibrated

C

When baseboards are connected ____, each receives water at the temperature supplied to the manifold. Select one: a. with copper tubing b. in series c. in parallel d. to a thermostat

C

When separate circulators are installed to zone a hot water system, the piping must include Select one: a. an air eliminator for each zone b. an expansion tank for each zone c. a flow control valve for each zone d. a back-flow preventer for each zone

C

A boiler operates at _____ efficiency only when it is being fired continuously under nonvarying conditions. Select one: a. manufacturer b. DOE-certified c. measurable d. steady-state

D

Although it is not a defined scientific term, it could be said that water is almost ____ times more "thermally concentrated" than air. Select one: a. 35 b. 3 c. 350 d. 3500

D

Cold start system require boilers that can Select one: a. Retain their heat over long periods of time b. run without a chimney connection c. have a tankless hot water heater installed in them d. resist damage from acid condensate

D

Hydronic fan-coils have two common components-a(n) ____ heat exchanger (often called the "coil") through which system fluid flows and a blower or fan that forces air to flow across the coil. Select one: a. ceramic b. cast iron c. open-looped d. finned-tube

D

The total liquid flow rate entering any portion of a fluid-filled (nonleaking) piping assembly will ____ the total flow rate exiting that assembly. Select one: a. never equal b. approximate c. might equal d. always equal

D

The water temperature circulating through a radieant heating system is controlled by a Select one: a. hot wanter control in the radiant piping loop b. three way valve in piping c. thermostat in the space to be heated d. hot water control in the boiler

D