Deck 44: Geothermal Heat Pumps

Question 1

Many coaxial heat exchangers are made of ____.

A) steel
B) aluminum
C) nickel
D) cupronickel

Answer 1

D

Question 2

Scale results in a low head pressure in the cooling mode and high suction pressure in the heating mode.

Answer 2

False

Question 3

Temperature, quantity, and cleanliness are three important factors that should be addressed when referring to water quality.

Answer 3

True

Question 4

When the water and refrigerant in a heat exchanger flow in opposite directions, it is referred to as ____.

A) countersink
B) parallel-flow
C) counter-flow
D) bias-flow

Question 5

Geothermal heat pumps use the ____________________ water as a heat source or a heat sink.

Question 6

Before deciding to purchase or install an open-loop system, the ____________________ must be evaluated first.

Question 7

An advantage of a "parallel flow" configuration of ground loops is ____.

A) smaller diameter pipes
B) ease of removing trapped air
C) simplified flow path
D) higher heat transfer per foot

Question 8

Open-loop, water-source heat pump systems involve the transfer of heat between a water source and the air or water being circulated to a(n) ____________________ space.

Question 9

In a geothermal heat pump system, there is a refrigerant loop and a water (water and antifreeze) loop.

Question 10

Since the Earth's crust is cooler than the air during the summer, it can be used to accept air conditioning heat loads.

Question 11

A domestic hot water loop is often used for heating domestic hot water from the hot discharge gas coming from the heat pump's refrigerant compressor.

Question 12

In a closed-loop system, the plastic water pipes that are buried in the Earth are called ____.

A) ground loops
B) thermal loops
C) water loops
D) both a and c

Question 13

In order to prevent water contamination, wells used for geothermal heat pump systems are grouted.

Question 14

What is the temperature differential between water in and water out of a heat exchanger that has transferred 50,000 Btu/h? The flow rate is 10 gallons per minute.

A) 5°
B) 10°
C) 20°
D) 50°

Question 15

Closed-loop, or ____________________, systems reuse the same heat transfer fluid, which is circulated in buried plastic pipes within the earth or within a lake or pond.

Question 16

The inner tube of heat exchangers of water-source heat pumps have extended surfaces called ____________________, which increase the surface area for better heat transfer.

Question 17

In a closed-loop system, the same fluid (water or water and antifreeze) will absorb heat from the ground in the winter and reject the heat to the ground in the summer.

Question 18

One of the minor differences between troubleshooting a geothermal heat pump and an air-to-air heat pump is how to gain access to pressures and temperatures in the water or ground loop.

Question 19

The hot gas line from the heat pump's compressor can be used to ____.

A) cool down the condenser
B) heat domestic water
C) keep the well water from freezing
D) both a and c

Question 20

An advantage of a "series flow" configuration of ground loops is ____.

A) smaller diameter pipes
B) ease of removing trapped air
C) lower installation costs
D) less antifreeze is required

Question 21

____________________________ heat pumps utilize two coaxial heat exchangers, as compared to only one on the water-to-air configuration.

Question 22

A(n) ____________________ blower is used to move the air through the air distribution system.

Question 23

A "dedicated" geothermal well is part of a(n) ____________________ system.

Question 24

The ground loop configuration that is used when there is a shortage of land is the ____________________.

Question 25

What are the advantages of a parallel-flow system?

Question 26

The ______________________ is nothing more than a large tank that both receives water from the condenser as well as supplying water to the condenser.

Question 27

List three characteristics of fluids used in heat exchange pumps.

Question 28

Three common types of antifreeze are salts, glycols, and ____________________.

Question 29

Of what are the buried pipes usually made?

Question 30

What are return wells used for?

Question 31

A dry well is most commonly used as part of a(n) ____________________ system.