Module 2 Section 2 Other Aspects of Heating

Question 1

List 6 characteristics of a good chimney

Answer 1

-removes combusti12on from house
-prevents poison gas from entering house
-minimizes heat loss from house
-controls the fire
-keep water out of house
-enhance appliance draft

Question 2

Give a short definition of:
a. chimneys
b. flues
c. vents

Answer 2

a. chimneys-used to carry exhaust products safely out of house
b. flues-interior passages within a chimney which gives move gases upwards from different fuel burning appliances
c. vents-metal devices for getting exhaust gases from burning fuels out of the house safely

Question 3

Chimneys may have multiple flues. T/F

Answer 3

True

Question 4

Masonry chimneys usually help support wood frame structures. T/F

Answer 4

False

Question 5

List 4 common fuels that need chimneys

Answer 5

Wood, oil, gas, propane

Question 6

List 6 things that affect chimney draft

Answer 6

height, flue size, any offset from vertical, appliance size, number of appliances, direction of prevailing wind

Question 7

List the 5 basic components of a masonry chimney

Answer 7

footing & foundation; vent connector; chimney walls; flue liner; chimney cap

Question 8

Why is condensation an issue in chimneys

Answer 8

condensation damages the masonry

Question 9

List at least 15 common chimney problems

Answer 9

settling/leaning; cracking; spalling masonry or concrete; loose or deteriorating masonry; loose/missing or deteriorating mortar; efflorescence; excessive offset from vertical; chimney too short; no liner; flute obstructed; cracked or broken liner; cap missing; cap cracked; too many appliances on flue; incomplete liner; abandoned opening for flue connections

Question 10

List 5 implications of chimneys settling or leaning.

Answer 10

structural failure; fire hazard; exhaust gas entry into house; water leakage or blocked flues; high maintenance & reduced durability of the chimney & adjacent house components

Question 11

List 4 implications of cracked chimneys

Answer 11

structural inability; fire hazard; exhaust gas entry into house; moisture entry; increased maintenance & reduced durability

Question 12

What is the maximum that a chimney can be offset from vertical

Answer 12

30 degrees max

Question 13

How far should a masonry chimney extend above the roof?

Answer 13

3 feet minimum & 2 feet above anything within 10 feet horizontally

Question 14

What is the minimum total height for a chimney serving a wood stove?

Answer 14

Minimum 15 feet

Question 15

When did masonry chimneys start to get built with clay liners?

Answer 15

Approximately the 1950s

Question 16

You can tell whether a chimney is lined by looking for a liner extending above the top. T/F

Answer 16

False

Question 17

Generally speaking, how far should wood framing members be kept away from masonry chimneys?

Answer 17

Minimum 2 inches

Question 18

Two wood burning fireplaces can share a single flue, as long as they are on the same floor level. T/F

Answer 18

False

Question 19

B vents are typically used for which fuels?

Answer 19

Natural gas & propane

Question 20

L vents are typically used for which fuels?

Answer 20

gas & oil

Question 21

Class A chimneys are typically used for which fuels?

Answer 21

oil & some wood burning appliances

Question 22

Factory-built chimneys are typically used for which fuels?

Answer 22

solid fuels

Question 23

Any B-vent can be installed up the outside of a house. T/F

Answer 23

False

Question 24

Metal chimneys often have several flues. T/F

Answer 24

False

Question 25

List 12 common metal chimney vent problems.

Answer 25

not labeled for application; sections not well secured; inadequate clearance from combustibles; inadequate fire stopping; no cap, wrong cap or obstructed cap; warped/buckled or twisted chimney walls; rusted or pitting; inadequate chimney height; creosote build up; excessive offset from vertical

Question 26

List at least one implication for each of chimney vent problems.

Answer 26

fire or life safety; fire hazard; poor draft;

Question 27

List at least one inspection strategy for chimney vent problems

Answer 27

look for labels that clarify the suitability if the application; check connecting sections; check above roof level/ensure it is level; check for proper standoffs/thimbles/clearances; ensure there are no gaps from top & bottom; check for a cap & make sure it is secure; check chimney walls anywhere they are exposed, above & below roof line; check all accessible sections of chimney for corrosion; chimney heights; check for creosote build up inside flue; follow chimney flue & watch for dramatic offsets; recommend further investigation; check number of chimneys against number of appliances; check for 16 inch clearance between metal chimneys

Question 28

Metal chimneys that extend more than _feet above the roof should be laterally supported.

Answer 28

greater than 5 ft

Question 29

Metal chimneys for wood fireplaces typically need _inches of clearance from combustibles.

Answer 29

2 inches

Question 30

What part of metal chimneys often rust? (location)

Answer 30

above roof line

Question 31

It is good practice to connect a metal chimney to a masonry chimney part way up a house so that the exterior part of the chimney is masonry. T/F

Answer 31

False

Question 32

Define creosote

Answer 32

Tar-like by product of incomplete combustion

Question 33

Which chimney is likely to have a heavier creosote deposit- a. warm chimney b cold chimney

Answer 33

Cold chimney

Question 34

List 3 types of wood-burning fireplaces

Answer 34

1. masonry fireplaces 2. factory built fireplaces

Question 35

Fireplaces can be built in or free standing. T/F

Answer 35

True

Question 36

Fireplaces are designed as a primary heating source in most cases. T/F

Answer 36

False

Question 37

List 7 basic components of a masonry fireplace.

Answer 37

footing & foundation; front hearth & back hearth; firebox; damper; throat/smoke shelf & smoke chamber; mantel; chimney

Question 38

Factory-built fireplaces do not have a smoke shelf. T/F

Answer 38

True

Question 39

How far should combustibles be from cleanout doors?

Answer 39

6 inches

Question 40

How far should combustibles be from fireplace openings?

Answer 40

6 inches

Question 41

How far above fireplace openings should combustibles be if they project out beyond the opening by 1 1/2"?

Answer 41

12 inches

Question 42

How far should combustibles be from firebox walls?

Answer 42

4 inches

Question 43

How far should combustibles be from chimneys?

Answer 43

2 inches

Question 44

How far should combustibles be from an outside combustion air inlet duct?

Answer 44

2 or 9 inches

Question 45

Zero clearance fireplaces do not typically require any clearance from combustibles at the top of the firebox. T/F

Answer 45

False

Question 46

A home inspection includes an analysis of the quality of a chimney f=draw for a fireplace. T/F

Answer 46

False

Question 47

Basement fireplaces typically draw better than first or second floor fireplaces because the chimney is taller. T/F

Answer 47

False

Question 48

Smoke on a mantel always means a poor drafting fireplace. T/F

Answer 48

False

Question 49

What words belong in pairs? hearth front hearth inner hearth outer hearth back hearth hearth extension

Answer 49

front hearth-back hearth inner hearth-outer hearth hearth-hearth extension

Question 50

Inside the firebox of a masonry fireplace, the surface of the hearth is typically___

Answer 50

firebrick

Question 51

The hearth extension typically sits on __inches of__

Answer 51

4 inches of poured concrete

Question 52

Hearths should extend__ inches out in front and __ inches to either side of the fireplace opening.

Answer 52

16 inches out & 8 inches to the side, or 20 inches in front & 12 inches to either side

Question 53

If the fireplace is raised, the hearth extension can be smaller. T/F

Answer 53

False

Question 54

List 7 common hearth problems

Answer 54

1. too small 2. gaps or cracks 3. settled 4. inappropriate material 5. wood forms not removed 6. too thin 7. evidence or overheating

Question 55

The function of a firebox is to ___

Answer 55

contain the fire

Question 56

A common minimum firebox depth requirement is _ inches.

Answer 56

20

Question 57

Metal fireboxes should be mortared tightly to the masonry of the fireplaces. T/F

Answer 57

False

Question 58

Clay tile liners should be supported on metal fireboxes. T/F

Answer 58

False

Question 59

Lintels should be mortared tightly into place. T/F

Answer 59

False

Question 60

Zero clearance fireplaces require footings & foundations. T/F

Answer 60

False

Question 61

List 8 common firebox problems

Answer 61

masonry/mortar loose; masonry refractory cracked; rust out/burnout; inappropriate materials; designed for coal; too shallow; lintels rusted/sagging/loose; draft suspect

Question 62

List 2 functions of a fireplace damper

Answer 62

allow exhaust products to leave house during operation; prevent cold air from entering house when fireplace is idle

Question 63

Can dampers ever be at the top of the chimney?

Answer 63

Yes

Question 64

Would you ever find a damper that was permanently open?

Answer 64

Yes, where gas logs have been inserted

Question 65

List 6 common damper problems.

Answer 65

missing; inoperative or obstructed; damper or frame rusted; frame loose; too low; undersized

Question 66

Describe the location & shape of the throat, the smoke shelf & the smoke chamber

Answer 66

1. throat-top of firebox below & at damper 2. smoke shelf-area behind damper nearly level 3. chamber-sloping section of fireplace above damper & throat, but below chimney flue

Question 67

Describe the characteristics of a well designed & well built smoke chamber.

Answer 67

Sides & front of chamber should slope and back should be vertical

Question 68

List 7 problems with throats, smoke shelves & smoke chambers.

Answer 68

missing, debris, excess slope, uneven slope, wood forms not removed, walls not smooth, rust

Question 69

List 6 fireplace, face or breast problems

Answer 69

cracked, settled, loose, combustible, evidence of overheating, too thick

Question 70

List 2 reasons why outdoor combustion air may be a good idea

Answer 70

1. makes fireplaces more efficient 2. modem tighter construction made it harder to supply air to fireplaces

Question 71

List 4 types of electric heating

Answer 71

space heaters; furnaces; boilers; radiant heating

Question 72

List 15 general electrical problems that you may find associated with electric heaters.

Answer 72

fuses/breakers missing; fuses/breakers too big; multi wire circuits on same bus; fuse/breakers bypassed; fuses breakers loose; no links for 240-volt circuits; wire overheating; wire damaged; wire not well secured; open splices

Question 73

Which is more dangerous; a 240-volt heater on a 120-volt circuit or a 120-volt heater on a 240-volt circuit?

Answer 73

120-volt heater on a 240-volt circuit

Question 74

List 8 problems specific to electric space heaters

Answer 74

inoperative heaters; obstructed heaters; dirty or bent fins on heaters; 120-volt heaters installed on 240-volt circuits or vice versa; fans-noisy/inoperative/loose or dirty

Question 75

What are common sizes for electric furnaces

Answer 75

10 to 30 kilowatt

Question 76

Briefly describe the operation of a sequencer

Answer 76

Sequencers prevent all of the elements from coming on at the same time. A time delay of 30 seconds between elements coming on allows the current flow to gradually build up.

Question 77

Describe how a staged electric furnace would come on

Answer 77

When thermostat calls for heat, only 1 or 2 elements will come on. If thermostat continues to sense that the temp. is still dropping, the next element will start. Once the room temp. begins to rise, no more elements will come on.

Question 78

Can you look at the elements on an electric furnace or boiler?

Answer 78

No

Question 79

What is the normal setting of a high temperature limit for an electric furnace?

Answer 79

200 degrees F

Question 80

What is a sail switch?

Answer 80

A switch that protects the elements from overheating by making sure there is adequate airflow across them.

Question 81

What is the typical temperature rise on an electric furnace?

Answer 81

50 to 60 degrees F

Question 82

List 2 common problem specific to electric furnaces.

Answer 82

Ductwork too small; burned out elements