Practice HVAC Licensing Exam 150 questions


1.
CFM = BTUH / (TR x 1.1)
bthu = 75,000 x .80 = 60,000

60,000 / 45 x 1.1)
60,000/ 49.5
= 1212 CFM
A 75,000 BTUH (INPUT RATING) 80% AFUE FURNACE HAS A TEMPERATURE RISE OF 45-DEGREES. WHAT IS THE CFM?




2.
Section 603 IMC
Pressure sensitve tapes used on flexible ducts shall be lableled as conforming to ______




3.
section 601
The use of gypsum boards to for plenums shall be limited to systems where the temperature does not exceed _______ degrees F and the temperature of the conveyed air is kept above the dew point




4.
503.10._ gas code
THE MAXIMUM HORIZONTAL LENGTH OF A SINGLE WALL CONNECTOR IS ______% OF THE HIEGHT OF THE CHIMNEY OR VENT.




5.
vel - cfm/ area in sq. ft.
12" x 30" = 360 sq. in.
360 sq. in / 144 = 2.5 sq. ft.
1400/2.5 = 560 FPM
WHAT IS THE VELOCITY OF 1400 CFM OF AIR IN A DUCT MEASURING 12" X 30"?




6.
Table 305.4 IMC
1/2" copper tubing must be supported a minimum of _______ feet when installed horizontally




7.
403 gas code
Which of the following gas piping materials shall not be used in exterior locations or underground




8.
section 504 IMC ( 35 feet minus 5 feet for each 90 degree bend)
Note: some older code allow for a max of 45 feet with a penalty of 10 feet for each 90 degree bend
The maximum length allowed fo a 4 inch dryer duct with two 90 degree bends is ______ feet




9.
404.Tracer
A tracer wire buried with plastic gas piping shall be minimum ___AWG




10.
Tabel 803.10.6 IMC
A single wall oil heat chimney connector shall have ______ clearance from combustibles




11.
see any service manual
AN AIR CONDITIONER HAS HIGH SUCTION AND A LOW HEAD PRESSURES. WHAT WOULD BE A LIKELY CAUSE?




12.
411 gas code
GAS APPLIANCE CONNECTORS SHALL NOT PASS THROUGH ANY OF THE FOLLOWING EXCEPT




13.
303.3 exception 3, and 304.5.1 gas code
(6000/1000) x 50 = 300 cubic feet minimum bath size
The maximum size unvented gas heater that may be installed in a residential bathroom measuring 1600 cubic feet is________bthu




14.
See "longest length method" in gas code appendix
THE DISTANCE FROM A METER TO A NATRUAL GAS WATER HEATER (40,000 BTUH) IS 30 FEET. 20 FEET FURTHER DOWN THE LINE IS A FURNACE (120,000 BTUH). WHAT IS THE MINIMUM PI[E SIZE THAT MUST BE USED BETWEEN THE WATER HEATER AND FURNACE? (PRESSURE LESS THAN 2 LBS, PRESSURE DROP = .05)?




15.
301 gas code
A label shall be affixed to the gas appliance with all the following information except _______




16.
306 mech code
Appliances installed on roofs greater than ______ feet high must have a permanent means of access.




17.
section 910 IMC
The control side of a floor furnce must have a minimum _____inches clearance




18.
setion 303 IMC
Appliance pits greater than 12 inches deep shall be lined with masonry extending ___inches above the adjoining grade




19.
section 504 IMC
Close dryers exhausting more than ____ cfm must be provided with make up air




20.
404.5 gas code
Where holes or notches for gas tubing are less than 1.5 inches from the nearest edge of a wood stud, they must be protected by metal shields not less than ____inch thick.




21.
404.14 Limitations. IFGC
Plastic pipe shall not be operated at pressures greater than ______ psig for LP gas




22.
section 506 IMC
Duct insulation installed within ____inches of a type I hood shall be noncombustible of be listed for the the applicatiomn




23.
Chapter 2 Definitions
A JOINT OBTAINED BY THE JOINING OF METAL PARTS WITH METALLIC MIXTURES OF ALLOYS WHICH MELT AT 1050 DEGREES F, IS CALLED A __________ JOINT.




24.
303 mechanical code
FUEL FIRED APPLIANCES SHALL NOT BE LOCATED IN _______.




25.
302 mech code
THE LARGEST A BORED HOLE MAY BE IN A 2' x 9.5" joist is




26.
section 402 IFGC
Unless welded or placed in a ventilated shaft, the maximnm operating pressure of gas piping in a residence shall not exceed _______ psig




27.
8/13 = .615
.615 x 650 = 400 op cost of new a/c
650- 400 = $250 savings
A CUSTOMER MOVES UP FROM AN 8 SEER TO A 13 SEER AIR CONDITIONER. WHAT WOULD HIS YEARLY SAVING BE IF HE WAS PAYING $650 PER YEAR FOR AIR CONDITIONING




28.
section 505 ( exception includes PVC in some cases
Downdraft kitchen exhaust ducts may be constructed of______.




29.
section 606 IMC
Duct smoke detectors shall comply with______.




30.
.36 x100/375 = .096 (rounded to .10) manual d
WHAT IS THE DESIGN FRICTION RATE WHEN THE AVAILABLE STATIC PRESSURE FOR THE DUCT SYSTEMIS .36" WC AND THE RUN WITH THE LONGEST EFFECTIVE LENGTH IS 375 FEET?




31.
302 MECH CODE
A NON LOAD BEARING STUD MAY BE NOTCHED ______% OF ITS DEPTH.




32.
section 304 IMC
Unless protected fom vehicle impact, appliances shall be installed a minimum ______ feet above the floor of a private garage




33.
section 501 IMC
Exhausted environmental air must be _____ feet from mechanical intakes




34.
Section 507 IMC( charcoal grille is extra heavy duty)
Which of the follow shall not share a typeI hood




35.
section 403 energy code
THE MINIMUM INSULATION R-VALUE FOR REFRIGERANT LINES FOR A RESIDENCE IS ____.




36.
305 gas code
IF PROTETION FROM VEHICLE IMPACT IS NOT PROVIDED, APPLIANCES INSTALLED IN PRIVATE GARAGES MUST BE INSTALLED _____ FEET ABOVE THE FLOOR.




37.
section 909 IMC
Vented wall furnaces shall be located so that a door cannot swing within _____ inches of the air inlets or outlets of such furnace measures at right angles to the openings




38.
section 301
A label shall be afixed to a gas appliance with all the following information except _______




39.
Table 403.9.2 gas code
When cutting threads, a 3/4 inch pipe shall have approximately _______ treads cut




40.
1102. mech code
RECLAIMED REFRIGERANTS SHALL NOT BE REUSED IN A DIFFERENT OWNERS EQUIPMENT UNLESS TESTED AND FOUND TO MEET THE PURITY REQUIREMENTS OF




41.
section 914
A sauna room shall have a vent opening above the door at least 4 inches by ____ inches




42.
section 403 IFGC
Copper piping shall not be used if the gas contains more than __ grains of hydrogen sulfide per 100 standard cubic feet.




43.
TABLE 503.4 gas code
CATEGORY I GAS EQUIPMENT MAY BE VENTED WITH WHICH OF THE FOLLOWING TYPES OF VENTS?




44.
Chapter 2 mech code "concealed location" definition
A location that cannot be accessed without damageing permanent parts of a building is called a/an _____ location




45.
Tablle 403.3 IMC (1500/1000 = 1.5, 1.5 x 50 people = 75 people, 75 x 20 cfm = 1500 cfm)
When mechanically ventilating a 1500 square foot conference room in an office building, how many CFM of outdoor air are required?




46.
$750 x .07 = $52.50
$750.00 + 52.50 = $802.50
100%-30% = 70% 0r .70
802.50/.70 = $1146.42
A CONTRACTOR PAYS $750 FOR A FURNACE PLUS 7% TAX. WHAT WOULD HIS SALES PRICE BE IF HE WISHED TO MAKE 30% GROSS PROFIT?




47.
405 gas code
When bending metallic gas pipe, the inside radius shall not be less than _____ times the diameter




48.
Table 403.3
The minimum ventilation rate for living area of a residence is the greater of 15 cfm per person or ____ air changes per hour




49.
use friction chart or duculator
THE VELOCITY OF 250 CFM OF AIR IN A FLEXIBLE, SPIRAL WIRE HELIX CORE DUCT SIZED AT .08" WC STATIC PRESSURE IS ______.




50.
section 604 IMC
Duct insulation shall have the R value printed every_________ inches




51.
section 506 IMC ( 24 / 12 = 2, 2 x 1/4" = 1/2")
The slope of a 24 foot horizontal grease duct must be at least ___ inch.




52.
404.9.1 gas code
A gas line serving a grill may be installed a minimum ______ inches as long as it is approved and not susceptible to physical damage




53.
Room cfm = HF X room heat lose
HF factor = 1200/48,000
HF= .025
Therefore: .025 x 5200 = 130 cfm
A HOUSE HAS A HEATING LOAD OF 48,000 BTUH. HOW MANY CFM ARE REQUIRED FOR A ROOM WITH A HEAT LOAD OF 5200 BTUH, USING A FURNACE WITH A 1200 CFM BLOWER?




54.
404 gas code
The unthreaded portion of a gas piping outlet shall not extend less then ______ through a slab floor




55.
section 606 IMC
Unless protected by approved area smoke detectors, smoke dedectors are required in the return air duct or plenum on any system with a design capacity greater than _______cfm.




56.
Table 308.6
IN A ROOM THAT IS LARGE IN COMPARISON WITH THE SIZE OF THE EQUIPMENT, AN APPLIANCE THAT REQUIRES 18" CLEARANCE ON ITS SIDES, MAY HAVE ITS CLEARANCE REDUCED TO ______ IF .024" SHEETMETAL WITH A VENTILATED AIR SPACE IS USED TO PROTECT THE COMBUSTIBLE SURFACE.




57.
304 IMC, 140,000/2000 = 70 square inches, 7 x 10 =70 square inches (Gas Code)
IN ORDER TO SUPPLY OUTDOOR COMBUSTION AIR USING THE TWO OPENING METHOD WITH HORIZONTAL DUCTS, WHAT DUCT SIZE BELOW WOULD BE THE MINIMUM NEEDED TO HANDLE A 140,000 BTUH FURNACE




58.
Table 415.1 gas code
For 3/4 inch steel gas pipe hangers or supports shall be spaced not farther than _____feet apart




59.
section 603 IMC (flexible connectors must be limited to 14 feet, not ducts)
Flexible air ducts______.




60.
Chapter 2 definitions of "regulator, medium pressure"
A gas regulator that reduces incoming pressure between .5 and 5 psig to a lower pressure is called a __________.




61.
section 507 (300 X 5 ft = 1500 cfm)
A type I hood, 5 foot long, wall mounted canapy, serving medium-duty appliances shall have a minimum capacity of _____ CFM




62.
404 gas code
Shield plates placed on studs to protect gas piping shall extend _____ inches to each side of the stud.




63.
section 706
When combustion air is mechanically forced into a room, a minumum rate of 1 cfm per _____ btu/h of combined input rating of all installed appliances must be supplied




64.
section 507 IMC
The verical distance between the front lower lip of a type I or II hood and the surface of the appliance shall not extend more than ______ feet




65.
409 gas code IFGC
For other than appliances installed in fireplaces, a gas shutoff valve shall be located within ___feet of the appliance




66.
section 403 energy code
Which of the following is not required for a heat pump installation




67.
section 601 IMC
Corridors are generaly not permitted to be used as return ducts, however the hallway of a tenant space ______ square feet or less may be used for return air.




68.
section 506 IMC
Type I grease ducts shall have a clearance of _____ inches to combustible construction




69.
section 1305 IMC
The vent cap of an oil tank must have a screen mesh no finer than No. _______




70.
section 403 IFGC
Brazing alloys used on gas piping shall not contain more than_____ percent phosphorus




71.
section 307 IMC
An auxiilary drain pan must have a minimum depth of ____ inche/s




72.
section 604 IMC
Duct lining shall be interupted _____ inches downstream of a duct heater




73.
section 304 IMC, says "within" 6 feet
Which rooftop appliance does not require guardrail protection?




74.
See "confined space " definition, 2006 IFGC. Note: confined space is no longer a defined term in the 2009 or later codes
AN APPLIANCE RATED AT 75,000 BTUH INPUT MUST BE PLACED IN A ROOM CONTAINING A MINIMUM ______ CUBIC FEET IN ORDER TO BE IN AN UNCONFINED SPACE.




75.
still air surface = .68
gypsum = .45
air space = .91
gypsum = .45
still air surface = .68
Total R = 3.17
U = 1/3.17 = .315
wall is 240 square feet (30 x 8)
BTUH = area x U x td
240 x .315 x 20 = 1512 (close enough)
A 30' X 8' PARTITION (2 X 4 STUDS, GYPSUM ON BOTH SIDES, NO INSULATION) SEPARATES TWO ROOMS HAVING A TEMPERATURE DIFERENCE OF 20 DEGREES. WHAT IS THE WINTER HEAT LOSS THROUGH THE PARTITION?




76.
48,000 btuh/ 50 degree TD = 960 btuh heat loss per degree TD
new TD 70F-40F = 30
30 DTD x 960 btuh/ DTD = 28,800 btuh
A HOUSE HAS A HEAT LOSSS OF 48,000 BTUH AT 20-DEGREE OUTDOOR TEMPERATURE. WHAT IS THE HEAT LOSS AT 40-DEGREE OUTDOOR TEMPERATURE?




77.
section R403 energy code
1500 sq. ft. / 100 = 15
15 x 4 =60 cfm
NOTE: the 2009 and earlier codes state 6 cfm/1000 sq.ft.
The maximum cfm of duct leakage allowed with a air handler in place for a 1500 square foot home with .1 inch w.g. is____.




78.
section 1305 IMC
The miminum size supply line to an oil furnace shall be _______ inch.




79.
section 802 imc
Unless otherwise specified by the manufacturer, vents shall terminate not less than ______feet above the highest connected appliance




80.
303 gas code, room must be 12 times larger than the appliance. Note this provision is not in all codes
A FUEL FIRED FURNACE, MEASURING 22 CUBIC FEET MUST BE PLACED IN A ROOM GREATER THAN __________ CUBIC FEET IF IT IS NOT APPROVED FOR CLOSET INSTALATION




81.
section 605 IMC
Liquid adhesive used on air filters shall have a flsh point no lower than ______ degrees F




82.
2012 energy code only
A HEAT PUMP IN A RESIDENCE MUST BE CONTROLLED BY WHICH OF THE FOLLOWING?




83.
Chapter 2 definition "recovered refrigerant" mech code
REFRIGERANTS REMOVED FROM A SYSTEM IN ANY CONDITION WITHOUT NECESSARILY TESTING OR PROCESSING THEM ARE CALLED___________.




84.
302 mech code
A DOUBLED UP STUD IN A LOAD BEARING WALL MAY HAVE A HOLE BORED UP TO ______% OF IT DEPTH




85.
section 506 IMC
Grease ducts shall provide an air velocity not less than _______ feet per minute




86.
see definition "vent", gas code
A vent is not _____




87.
section 914 IMC
Sauna heaters shall have a thermostat that limits the room temperature to _______ degrees F




88.
Manual D square to round tables
A 12" ROUND DUCT HAS A RECTANGULAR EQUIVALENT OF




89.
sectiopn 602 IMC
Which of the following must have a flame spread rating no greater than 5 feet when intalled in plenums.




90.
section 307 IMC
If a water level detection device is used in an auxiliary drain pan it must conform to_______.




91.
403 gas code
___________ pipiing may only be used for gas piping outside and underground.




92.
section 506 Grease duct enclosure
Grease ducts in enclosures shall have a clearance of ________ inches to construction of non combustible gypsum attached to non combustible structures




93.
section 708 IMC, also 304.6 IFGC
The minimum cross-sectional dimension of a combustion air duct shall be ________ inches




94.
404 gas code
Gas piping installed underground beneath buiding may not be incased in _________.




95.
section 506 IMC
A commercial stainless steel duct must be constructed of ______ gage thickness




96.
section 307
A plastic condensate pan must have a minimum thickness of ______ inch




97.
402 gas code
The maximum operating pressure of LP gas systems shall not exceed ____ unless the building or area is constructed according to NFPA 58, Chapter 10




98.
Only R values can be added or subtracted, therefore, convert the U value to R value (1/.07 = 14.28).
add R 19 + R 14.28 = R 33.28
A CEILING HAS A TOTAL U-VALUE OF .07. WHAT IS THE NEW R-VALUE IF R-19 IS ADDED?




99.
304.5.1 gas code
15 x 20 x 8 = 24,000 cubic ft.
24,000 / 50 = 48
48 x 1000 = 48,000 bthu
THE MAXIMUM BTUH RATING OF AN UNVENTED GAS HEATER INSTALLED IN A 15 X 20 ROOM WITH 8 FOOT CEILINGS IS (infiltraion rate is greater than .40 ACH)?




100.
section 306 IMC
Underfloor accesses must be a minimum 22 inches high by _______ inches wide




101.
section R403 energy code
The minimum R value of duct insulation installed in areas other than the conditioned space or attics is _________




102.
chapter 2 definitions, gas code
A system desgned to shut off the gas supply to the burners if the oxygen in the surrounding atmosphere is reduced to a predetermined level is called a ___________




103.
section 305 IMC
Shield plates on studs must be a minimum ____ - inch thick




104.
section 603 IMC
Floor registers must support ______lbs consetrated load on a 2 inch disk appliedati its most critical area




105.
section 607 IMC
Access points for inspecting and servicing fire dampers shall be labeled FIRE DAMPER with letter no tess than _____ inch/s high




106.
.55 - .03- .03 - .15 -.10 = .24' wc
A BLOWER WITH AN EXTERNAL STATIC PRESSURE OF .55" WC IS CONNECTED TO A 70 FT. LONG DUCT. THE SYSTEM INCLUDES REGISTERS AND GRILLS (.03" WC EACH), A COOLING COIL (.15" WC) AND FILTER (.10" WC). WHAT IS THE TOTAL AVAILABLE STATIC PRESSURE REMAINING FOR SIZING THE DUCT?




107.
$75,000/.15 = $500,000
IF A CONTRACTOR WORKS ON 15% PROFIT, WHAT WOULD HIS SALES HAVE TO BE TO MAKE $75,000?




108.
section 406 (5 x test pressure)
When using a test pressure of 10 psig, the test guage shall not be capable of reading pressures greater than_____PSIG




109.
Defintions, gas code
A vertical pipe supplying gas is a________




110.
Section 603 IMC
Unless otherwise approved, ducts shall not be instlalled within ____ inches of earth.




111.
section 910 IMC
A floor furnace shall be placed such that a drapery can be no nearer than ______ to the register of the furnace




112.
Section 506 IMC
Exhaust outlets that terminate above a roof shall have a discharge outlet not less than ___ inches above the roof surface




113. This question eliminated


114.
definitions-listed
Equipment, appliances or material included in a list published by a nationally recognized testing laboratory concerned with product evaluation and states that the above item meets recognized standards is said to be _____________




115.
section 903 IMC
Factory built fireplaces must be listed and labeled according to __________.




116.
section 701 IMC
When obtaining combustion air from an attic, a minimum 26 gage galvanized sheet metal sleeve must be used and extended ________ inches above the joists and insulation




117.
section 404 IMC (10,000 x 1.5 = 15,000)
A ventilation system in a 10,000 squire foot enclosed parking garage shall be capable of producing a minimum of _____ cfm




118.
Table C403.2.3 (2) energy code
The minimum allowable HSPF rating of an air cooled rsidential heat pump is _________




119.
section 309 IMC
A home must be provided with a space heating system capable of maintaing a minimum indoor temperature of _____ degree at a point 3 feet obove the floor level on a design heating day




120.
section 202 IFGC
A gas regulator that reduces incoming pressure between .5 and 5 psig to a lower pressure is called a __________.




121.
section 306 IMC
Passageways in attics shall not be less than _____ inches wide




122.
Use Table 504.3(1), IFGC, Remember to use the 15 ft. height not 20 ft.
TWO NATURALLY VENTILATED APPLIANCES WITH A COMBINED CAPACITY OF 130,000 BTUH ARE CONNECTED TO A COMMON B-VENT, 18' HIGH WITH TWO 90-DEGREE ELBOWS. WHAT SIZE COMMON VENT SHOULD BE USED?




123.
section 402 IMC (3000 X .04 = 120)
If natural ventilation is used, a building, measuring 3000 square feet, must have a minimum openable area of ______ square feet.




124.
305 gas code
The ignition source of an appliance shall be elevated not less than _____ unless it is lisred as flammable ignition resistant




125.
Table 603.4
The minimum gage for a 14 inch round galvanized air duct is ___.




126.
Table 404 IMC
Screens used to protect intake openings for ventilation may not have a mesh less than____ inch.




127.
section 504 IMC
Closets containing close dryers must have a make up air opening not less than ____ square inches




128.
1,000,000/140,000 = 7.143 gals
7.143/.80 = 8.928 gals @ 80% efficiency
8.928 x $1.25 = $11.60
IF A GALLON OF OIL CONTAINING 140,000 BTU'S SELLS FOR $1.25, HOW MUCH WILL 1,000,000 BTU'S COST WHEN USED IN AN 80% AFUE OIL FURNACE




129.
Tabel 803.9(1) IMC
A single wall low heat 6 inch diameter chimney connecter shall have a minimum thickness of ______




130.
section 504 IMC
The minimum diameter of a close dryer duct shall be ______ inches




131.
NASCLA business book or look up ADA
THE AMERICANS WITH DISABILITIES ACT APPLIES TO ALL EMPLOYERS WHO HAVE _______ OR MORE EMPLOYEES




132.
section 506 IMC
Cleanouts located on horizontal grease ducts shall be placed not more than ____feet apart




133.
section 918 IMC( 80000/1000 =80, 80 x 2" = 160 square inches)
The minimum return opening to an 80,000 btuh (output rating) forced air furnace shall be _____ square inches.




134.
section 307 IMC
Condensate piping must no be less than _____ inch diameter




135.
Table 507 IMC
The minimum distance between the cooking surface and a grease filter serving burners with flames is _____ feet




136.
section 507 IMC
A type I hood is not required for _______>




137.
Chapter 2, definitions gas code
A location that cannot be accessed without damageing permanent parts of a building is called a/an _____ location




138.
section 604 IMC
When aluminum foil is used as a vapor retarder for duct insulation it must be minimum
_____ mils thick




139.
section 709 ( 6 x10 = 60 sq. in., 60/.75 = 80 sq. in.)
If an 6" X 10" duct is terminated with a metal louver (75% free area), the louver must be a minimum _____ square inches




140.
Table 403.3 mech code
table assumes 50 people /1000 sq ft
Therefore 25 people would occupy 500 sq ft
25 people x 20 cfm/person = 500 cfm
A 500 SQUARE FOOT CONFERENCE ROOM REQUIRES _______CFM OF OUTDOOR VENTILATION




141.
section 401
Gas piping shall be labeled at intervals not exceeding ______ feet




142.
404 gas code
Gas piping may be joined in concealed locations using which of the following methods?




143.
Table 607
A fire damper install at a 2 hour fire rated wall shall have a minimum rating of _______ hours




144.
table 406.7.1 gas code
A 2 inch diameter gas pipe must be purged with an inert gas before opening if it is greater than _____feet long.




145.
section 504 IMC
Transition ducts used to connect commercial dryers to exhaust duct shall be limited to ___ feet in length




146.
SECTION 503 LENGTH OF VENT CONNECTOR, GAS CODE
THE MAXIMUM ALLOWABLE HORIZONTAL LENGTH OF A CATEGORY I APPLIANCE SINGLE WALL VENT CONNECTOR IS _______% OF THE HEIGHT OF THE VENT




147.
Gas Code definitions "vented appliance categories"
An appliance that causes a positive vent pressure and produces excessive condensation in the vent is a Catagory ______ appliance




148.
section 701 imc
When obtaining combustion air from a crawl space, the free area of the crawl space vent to the outside must be a minimum ________ the size of the combustion air opening




149.
70F-20F = 50F TD
BTUH = CFM x 1.1 x TD
= 300 x 1.1 x 50
= 16,500 BTUH
=
FOR A BUILDING TO BE MAINTAINED AT 70 F, HOW MANY BTUH ARE REQUIRED TO OFFSET 300 CFM OF 20 F OUTDOOR VENTILATION?




150.
section 701 IMC
The highest point of an attic must be at least ___inches in order to be used as a source for combustion air




151.
411.1 gas code
Semi-ridgid metallic tubing used as appliance connectors shall not exceed ___ feet




152.
section R401 energy code
Which of the following heating systems must have its efficiecy posted on a certificate placed on or inside the electircal distribution panel of new residential construction




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