Land Use and Environmental Service Agency
(Code Enforcement)
Mechanical Q & A 2002
Attention: √ Denotes a new question!
General:
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September 2002
(Q) Which code (Energy) may a contractor use to calculate a structures
HVAC loads?
(A)
Contractors may use Chapter 11 of the North Carolina
Residential Code or the North Carolina Energy Code.
(Q) When are a flues cap, collar and flashing required to be installed?
(A) By the Final inspection.
(Q) When is an attic HVAC (Complete) system in a new residence
required to be installed?
(A) During the structures rough phase, prior to the installation of
sheetrock.
(Q) Do fire logs need to be assembled to achieve a final inspection?
(A)
Appliance installation must be completed prior to final
inspection including the assembly of fire logs.
Duct:
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(Q) Does the make-up air for an HVAC system need insulating?
(A) All duct must meet the Code!
(Q) What part of a panned floor joist (used as plenum) is required to be
insulated?
(A) The metal used to pan the joist!
(Q) May treated wood be placed in a ceiling return air plenum?
(A) No wood may be placed in a ceiling return air plenum.
(Q) May a removable flex connection on a UL181 flex duct system, be
used to reset a fire damper?
(A) Yes! Provided that it connects to a round damper installed per its
listing, the clamp is a worm/screw type clamp and the connection is
accessible on all sides.
(Q) May flex duct for make-up air be connected directly to a grease hood?
(A) No! Duct connecting directly to a grease hood must be metal.
(Q) When is a restaurant required to install a type I hood verses a type II
Hood?
(A) Type I Hood is required for commercial food heat-processing
appliance that produce grease vapors or smoke (includes pizza
restaurants). Type II hood produce little, if any, grease-laden vapor.
Examples: pastry, bread, cookies, cakes, steam tables, dish washing
machines, heat/fumes/odors, toasters, coffee makers and convection
or small conveyor type pizza ovens (convenient stores, etc. but does
not include pizza restaurants)
(Q) What is the minimum depth allowed for a return box with a filter grill?
(A) There needs to be at least 12” depth measured from the back of
Land Use and Environmental Service Agency
(Code Enforcement)
Mechanical Q & A 2002
8)√
the filter grill and the back of the box where the starting collar is
connected. Depths less than the 12” would create excessive
turbulence and would not meet SMACNA standards.
(Q) Does Code the require the duct to be extended to the face of the
cabinet baseboard when a register/duct is installed.
(A) Yes! The duct must be extended to the face. The dead space
under cabinets can not be used as a plenum.
Equipment:
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(Q) The Code, (Section 306) requires openings large enough to remove
the largest piece of equipment. Where are the measurements to be
taken?
(A) Adequate room to remove the largest piece of equipment
“without removing permanent components” is required. The
measurements are to be taken from the inside of the frame or door
stops. You are allowed to remove the pins from a hinge, hardware
(i.e. springs, etc.) that is attached with screws (not rivets) or covers
that are attached with screws. You may not remove doorstops,
doorframes or any components nailed in place.
Did You Know?
1) √
During the physical year 2001/2002 (July 1, 2001 – June 30, 2002) there
were 60, 847 mechanical inspections performed. There were 867 failures
attributed to no equipment access (Code E4) which includes no ladder,
locked roof access door, locked storage room door, etc. The results show
that approximately 1/10 of 1% of jobs failed due to no acc7ess.