3.1

Question 3

Typical domestic uses of hot water include cooking , ____________, bathing, and ________________.

Answer 3

cleaning, space heating

Question 4

Energy consumption for heating ____________ is the second largest energy user (after _____________) in the residential sector in industrialized countries, accounting for about ____% of the energy used in a typical household.

Answer 4

domestic water, space heating, 14

Question 5

an appliance that heats water for domestic or building service hot water use

Answer 5

water heater

Question 6

what are the three types of water heaters

Answer 6

1. storage tank water heaters
2. instantaneous on - demand ( tankless) water heaters
3. circulating water heaters

Question 7

4 types of heater models:

Answer 7

1. Natural Gas
2. Propane
3. Fuel Oil
4. Electric

Question 8

• use their fuel to run a burner;
• they have burners on the bottom of the tank and a vent that passes up through the center of the tank;

Answer 8

Natural Gas

Question 9

more dangerous than electric heating (CO) is produced by gas heating

Answer 9

Natural Gas

Question 10

• uses liquid petroleum gas as its fuel source to heat water for household use;
• used in homes that are not connected to natural gasline, rural areas, or with high electricity cost

Answer 10

Propane ( LP)

Question 11

safety concerns ( flammable gas)

Answer 11

Propane

Question 12

uses _____________ as its fuel source instead of gas or electricity to heat water for household use;

used in homes that have acces to oil delivery

Answer 12

fuel oil

Question 13

large water volume capacity and maintenance needs

Answer 13

fuel oil

Question 14

• have coil like elements that extend into the tank;
• heats water as ____________________ passes through it

Answer 14

electric

electric current

Question 15

• ______________ sizes: 30, 40, 50, 60, 65, 75, 80,100, and 120-gal capacity;

Answer 15

storage tank

Question 16

remains the most popular type for residential heating needs

Answer 16

storage tank water heater

Question 17

In storage tank water heater, a ______________ serves as control of heating medium

Answer 17

thermostat

Question 18

3 types of heaters:

Answer 18

1. Residential
2. Commercial
3. Ultraefficient Water Heaters

Question 19

use power burners and enhanced heat exchangers to force hot combustion gases into chambers

Answer 19

ultra efficient water heater

Question 20

draws comsution air directly from the outside

Answer 20

ultra efficient water heater

Question 21

vented with plastic pipes that go through an outside wall

Answer 21

ultra efficient water heater

Question 22

aka tankless water heaters or demand water heaters;

• have a heating device that is activated by the ___________ when a hot water valve is opened;
• output of the heater limits the rate of heated _____________;
• come in a variety of sizes for different applications;

Answer 22

instantaneous (tankless) water heaters, flow of water, water flow

Question 23

• can provide all the hot water needs of a household;
• installed centrally;
• may not supply enough hot water for simultaneous, multiple uses of hot water

Answer 23

largest gas - fired units

Question 24

• fit compactly under a fixture;
• heat water at the location where it is used;
• saves on piping installation costs

Answer 24

Point - of - use water heaters

Question 25

consists of a separate storage tank which stores water heated by a heat exchanger

Answer 25

circulating water heaters

Question 26

- may be separate (heated by stream); - may be hot water from a boiler; - contained in a boiler

Answer 26

Circulating Water Heaters Heat Exchanger

Question 27

limited hot water capacity , less flexible and potential high installation costs

Answer 27

cons of electric

Question 28

- no separate storage tank is needed; - works best during colder months and is less efficient during warmer months

Answer 28

Tankless Coil Water Heater

Question 29

- extract energy from outdoor air and use it to produce hot water very efficiently; - use an electric motor to run a compressor - makes economic sense in hot humid regions where natural gas is unavailable,electric energy cost is high, and the need for dehumidification is constant

Answer 29

Heat Pump Water Heaters

Question 30

- includes collectors mounted in the roof or in a clear area of the yard, a separate storage tank near the heater at home,connecting pipes, and an electronic controller; - _________________ preheats the water before it reaches the water heater; - reduces the annual fuel cost by supplying hot water to a residence by more than half.

Answer 30

Solar Water Heaters, solar system

Question 31

- a device that injects a controlled amount of water into a steam flow to lower the temperature of the steam. - has two types: direct and indirect contact

Answer 31

desuperheaters

Question 32

- process of restoring superheated steam to its saturated state through temperature reduction

Answer 32

desuperheating/ steam conditioning

Question 34

- requires a separate storage tank - heated water flows to an insulated storage tank in indirect water heater.

Answer 34

Indirect Water Heater