Module 2 Section 2 Other Aspects of Heating Flashcards
List 6 characteristics of a good chimney
-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
Give a short definition of:
a. chimneys
b. flues
c. vents
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
Chimneys may have multiple flues. T/F
True
Masonry chimneys usually help support wood frame structures. T/F
False
List 4 common fuels that need chimneys
Wood, oil, gas, propane
List 6 things that affect chimney draft
height, flue size, any offset from vertical, appliance size, number of appliances, direction of prevailing wind
List the 5 basic components of a masonry chimney
footing & foundation; vent connector; chimney walls; flue liner; chimney cap
Why is condensation an issue in chimneys
condensation damages the masonry
List at least 15 common chimney problems
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
List 5 implications of chimneys settling or leaning.
structural failure; fire hazard; exhaust gas entry into house; water leakage or blocked flues; high maintenance & reduced durability of the chimney & adjacent house components
List 4 implications of cracked chimneys
structural inability; fire hazard; exhaust gas entry into house; moisture entry; increased maintenance & reduced durability
What is the maximum that a chimney can be offset from vertical
30 degrees max
How far should a masonry chimney extend above the roof?
3 feet minimum & 2 feet above anything within 10 feet horizontally
What is the minimum total height for a chimney serving a wood stove?
Minimum 15 feet
When did masonry chimneys start to get built with clay liners?
Approximately the 1950s
You can tell whether a chimney is lined by looking for a liner extending above the top. T/F
False
Generally speaking, how far should wood framing members be kept away from masonry chimneys?
Minimum 2 inches
Two wood burning fireplaces can share a single flue, as long as they are on the same floor level. T/F
False
B vents are typically used for which fuels?
Natural gas & propane
L vents are typically used for which fuels?
gas & oil
Class A chimneys are typically used for which fuels?
oil & some wood burning appliances
Factory-built chimneys are typically used for which fuels?
solid fuels
Any B-vent can be installed up the outside of a house. T/F
False
Metal chimneys often have several flues. T/F
False
List 12 common metal chimney vent problems.
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
List at least one implication for each of chimney vent problems.
fire or life safety; fire hazard; poor draft;
List at least one inspection strategy for chimney vent problems
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
Metal chimneys that extend more than _feet above the roof should be laterally supported.
greater than 5 ft
Metal chimneys for wood fireplaces typically need _inches of clearance from combustibles.
2 inches
What part of metal chimneys often rust? (location)
above roof line
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
False
Define creosote
Tar-like by product of incomplete combustion
Which chimney is likely to have a heavier creosote deposit-
a. warm chimney
b cold chimney
Cold chimney
List 3 types of wood-burning fireplaces
- masonry fireplaces
- factory built fireplaces
Fireplaces can be built in or free standing. T/F
True
Fireplaces are designed as a primary heating source in most cases. T/F
False
List 7 basic components of a masonry fireplace.
footing & foundation; front hearth & back hearth; firebox; damper; throat/smoke shelf & smoke chamber; mantel; chimney
Factory-built fireplaces do not have a smoke shelf. T/F
True
How far should combustibles be from cleanout doors?
6 inches
How far should combustibles be from fireplace openings?
6 inches
How far above fireplace openings should combustibles be if they project out beyond the opening by 1 1/2”?
12 inches
How far should combustibles be from firebox walls?
4 inches
How far should combustibles be from chimneys?
2 inches
How far should combustibles be from an outside combustion air inlet duct?
2 or 9 inches
Zero clearance fireplaces do not typically require any clearance from combustibles at the top of the firebox. T/F
False
A home inspection includes an analysis of the quality of a chimney f=draw for a fireplace. T/F
False
Basement fireplaces typically draw better than first or second floor fireplaces because the chimney is taller. T/F
False
Smoke on a mantel always means a poor drafting fireplace. T/F
False
What words belong in pairs?
hearth front hearth
inner hearth outer hearth
back hearth hearth extension
front hearth-back hearth
inner hearth-outer hearth
hearth-hearth extension
Inside the firebox of a masonry fireplace, the surface of the hearth is typically___
firebrick
The hearth extension typically sits on __inches of__
4 inches of poured concrete
Hearths should extend__ inches out in front and __ inches to either side of the fireplace opening.
16 inches out & 8 inches to the side, or 20 inches in front & 12 inches to either side
If the fireplace is raised, the hearth extension can be smaller. T/F
False
List 7 common hearth problems
- too small
- gaps or cracks
- settled
- inappropriate material
- wood forms not removed
- too thin
- evidence or overheating
The function of a firebox is to ___
contain the fire
A common minimum firebox depth requirement is _ inches.
20
Metal fireboxes should be mortared tightly to the masonry of the fireplaces. T/F
False
Clay tile liners should be supported on metal fireboxes. T/F
False
Lintels should be mortared tightly into place. T/F
False
Zero clearance fireplaces require footings & foundations. T/F
False
List 8 common firebox problems
masonry/mortar loose; masonry refractory cracked; rust out/burnout; inappropriate materials; designed for coal; too shallow; lintels rusted/sagging/loose; draft suspect
List 2 functions of a fireplace damper
allow exhaust products to leave house during operation; prevent cold air from entering house when fireplace is idle
Can dampers ever be at the top of the chimney?
Yes
Would you ever find a damper that was permanently open?
Yes, where gas logs have been inserted
List 6 common damper problems.
missing; inoperative or obstructed; damper or frame rusted; frame loose; too low; undersized
Describe the location & shape of the throat, the smoke shelf & the smoke chamber
- throat-top of firebox below & at damper
- smoke shelf-area behind damper nearly level
- chamber-sloping section of fireplace above damper & throat, but below chimney flue
Describe the characteristics of a well designed & well built smoke chamber.
Sides & front of chamber should slope and back should be vertical
List 7 problems with throats, smoke shelves & smoke chambers.
missing, debris, excess slope, uneven slope, wood forms not removed, walls not smooth, rust
List 6 fireplace, face or breast problems
cracked, settled, loose, combustible, evidence of overheating, too thick
List 2 reasons why outdoor combustion air may be a good idea
- makes fireplaces more efficient
- modem tighter construction made it harder to supply air to fireplaces
List 4 types of electric heating
space heaters; furnaces; boilers; radiant heating
List 15 general electrical problems that you may find associated with electric heaters.
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
Which is more dangerous; a 240-volt heater on a 120-volt circuit or a 120-volt heater on a 240-volt circuit?
120-volt heater on a 240-volt circuit
List 8 problems specific to electric space heaters
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
What are common sizes for electric furnaces
10 to 30 kilowatt
Briefly describe the operation of a sequencer
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.
Describe how a staged electric furnace would come on
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.
Can you look at the elements on an electric furnace or boiler?
No
What is the normal setting of a high temperature limit for an electric furnace?
200 degrees F
What is a sail switch?
A switch that protects the elements from overheating by making sure there is adequate airflow across them.
What is the typical temperature rise on an electric furnace?
50 to 60 degrees F
List 2 common problem specific to electric furnaces.
Ductwork too small; burned out elements