MODULE 13 G2 QUESTIONS AND CORRECT VERIFIED ANSWERS

MODULE 13 G2 QUESTIONS AND
CORRECT VERIFIED ANSWERS
AirA2supplyA2toA2aA2gas-firedA2applianceA2includes:A2-A2Ans--
a)AirA2requiredA2forA2satisfactoryA2combustionA2ofA2naturalA2gasA2orA2propane.
b)A2AmbientA2airA2thatA2isA2admittedA2intoA2theA2ventingA2systemA2toA2controlA2ventingA2act
ion.
c)A2AirA2thatA2isA2admittedA2toA2aA2spaceA2containingA2anA2applianceA2toA2replaceA2airA2ex
haustedA2throughA2ventilationA2openings.

DefineA2"DraftA2Intensity"A2-A2Ans--
TheA2rateA2ofA2flowA2ofA2airA2orA2combustionA2products,A2orA2both,A2throughA2anA2applianc
eA2andA2itsA2ventingA2system

WhichA2ofA2theA2followingA2statementsA2isA2correct?A2-A2Ans--
GasesA2flowsA2fromA2aA2highA2pressureA2toA2aA2lowerA2pressure.

ToA2adjustA2anyA2draftA2measurementA2gaugeA2toA2readA2zero,A2oneA2ofA2theA2twoA2sensi
ngA2portsA2onA2theA2instrumentA2mustA2toA2beA2plugged.A2-A2Ans--False

IfA2aA2draftA2readingA2ofA2-
A202"A2w.c.A2isA2foundA2whenA2theA2sensingA2tubeA2isA2positionedA2inA2theA2ventA2ofA2aA2na
turalA2draftA2ventedA2appliance:A2-A2Ans--
TheA2ventA2isA2removingA2theA2productsA2ofA2combustionA2fromA2theA2appliance.

IfA2aA2draftA2readingA2ofA2+A202"A2w.c.A2isA2foundA2onA2aA2conventionalA2ventA2applianceA2
whenA2theA2sensingA2tubeA2isA2positionedA2inA2theA2vent:A2-A2Ans--
TheA2ventA2isA2spillingA2theA2productsA2ofA2combustion.

AllA2pressureA2measurementsA2ofA2airA2supplyA2andA2ventingA2systemsA2areA2basedA2onA2
zeroA2pressureA2being:A2-A2Ans--LocalA2atmosphericA2pressure.

WhatA2causesA2negativeA2pressureA2inA2aA2building?A2-A2Ans--
TheA2volumeA2ofA2airA2leavingA2theA2buildingA2exceedsA2theA2volumeA2ofA2airA2enteringA2th
eA2building.

WhichA2ofA2theA2followingA2differentialA2airA2pressureA2readingsA2takenA2betweenA2theA2ro
omA2pressureA2andA2theA2pressureA2inA2theA2ventA2connectorA2ofA2aA2naturalA2draftA2appli
anceA2indicateA2theA2fastestA2flowA2rateA2ofA2flueA2gasesA2outA2ofA2theA2ventA2toA2theA2outd
oors?A2-A2Ans---0.5"A2w.c.

WhyA2areA2naturalA2draftA2burnersA2moreA2sensitiveA2toA2negativeA2buildingA2pressureA2th
anA2powerA2burners?A2-A2Ans--
TheyA2doA2notA2employA2aA2mechanicalA2deviceA2toA2deliverA2combustionA2air.

, WhatA2problemsA2mayA2occurA2toA2combustionA2orA2ventingA2ifA2theA2airA2shuttersA2onA2aA
2naturalA2draftA2burnerA2wereA2pluggedA2withA2dirt?A2-A2Ans--
FlameA2mayA2beA2longA2andA2yellow.A2IncompleteA2combustion.A2FlameA2roll-out.

WhatA2problemsA2mayA2occurA2toA2combustionA2orA2ventingA2ifA2theA2airA2shuttersA2onA2aA
2powerA2burnerA2wereA2pluggedA2withA2dirt?A2-A2Ans--
FlameA2mayA2beA2longA2andA2yellow.A2IncompleteA2combustion.

WhatA2effectA2couldA2positiveA2pressureA2inA2aA2buildingA2haveA2onA2theA2naturalA2venting
A2ofA2anA2applianceA2thatA2isA2equippedA2withA2aA2draftA2hood?A2-A2Ans--
LiftingA2flame;A2decreasedA2efficiency.

WhatA2effectA2couldA2positiveA2orA2negativeA2pressureA2inA2aA2buildingA2haveA2onA2theA2ve
ntingA2ofA2aA2directA2ventA2appliance?A2-A2Ans--None

WhatA2changesA2mayA2occurA2toA2theA2combustionA2processA2andA2applianceA2efficiencyA
2ifA2theA2negativeA2furnaceA2pressureA2isA2increasedA2(e.g.A2fromA2-.01A2toA2-A204)?A2-
A2Ans--DecreasedA2efficiency,A2liftingA2flame.


AA2"zeroA2over-the-
fire"A2pressureA2isA2requiredA2onA2mostA2gasA2appliancesA2toA2ensureA2that:A2-A2Ans--
a)TheA2burnerA2blowerA2doesA2notA2haveA2toA2overcomeA2aA2positiveA2chamberA2pressure
.
b)A2FlueA2gasesA2doA2notA2spillA2outA2ofA2theA2heatA2exchangerA2atA2theA2inspectionA2door
A2orA2burnerA2mountingA2plate.
c)A2TheA2flueA2gasesA2doA2notA2exitA2theA2combustionA2chamberA2tooA2rapidlyA2andA2there
byA2reduceA2applianceA2efficiency.

WhyA2areA2mostA2appliancesA2designedA2forA2aA2negativeA2furnaceA2pressure?A2-A2Ans--
SaferA2sinceA2flueA2gasesA2willA2notA2spillA2outA2ofA2anyA2opening;A2cheaperA2toA2build;
CanA2employA2atmosphericA2burners;A2needsA2fewerA2controls

AnA2applianceA2thatA2isA2operatedA2withA2aA2positiveA2furnaceA2pressureA2will:A2-A2Ans--
a)SpillA2flueA2gasesA2insideA2theA2buildingA2unlessA2theA2applianceA2isA2tightlyA2sealed.
b)A2BeA2equippedA2withA2aA2burnerA2and/
orA2blowerA2thatA2controlsA2allA2airA2flowA2toA2theA2appliance.
C)A2HaveA2greaterA2controlA2overA2theA2amountA2ofA2excessA2airA2introducedA2intoA2theA2a
ppliance.

WhichA2oneA2ofA2theA2followingA2appliancesA2wouldA2removeA2theA2greatestA2volumeA2ofA2
airA2fromA2aA2buildingA2ifA2theyA2allA2haveA2theA2sameA2inputA2rating?A2-A2Ans--
NaturalA2draftA2ventedA2furnaceA2equippedA2withA2aA2draftA2controlA2device.

AA2properlyA2sizedA2outdoorA2airA2intakeA2isA2designerA2toA2supply:A2-A2Ans--
DilutionA2airA2andA2combustionA2airA2requirements.