NEW AG SHOP FOR PISGAH HIGH SCHOOL
JACKSON COUNTY BOARD OF EDUCATION
PISGAH, ALABAMA
SECTION 15840
DUCTWORK
PART ONE - GENERAL:
1.1
SCOPE:
A.
Include Section 15010, "GENERAL PROVISIONS - HVAC", with this section.
B.
Provisions of this Section shall apply to all HVAC work.
1.2
SHOP DRAWINGS:
A.
Ductwork shop drawings shall include details of duct constructions: seams, joints, gauges,
reinforcing and hanger details for each pressure class and size range together with details of
turning vanes, branch connections, dampers and access doors and elevations of all ductwork.
PART TWO - PRODUCTS:
2.1
DUCTWORK - GENERAL:
A.
Unless otherwise shown or specified construct ducts of galvanized steel sheet metal using gauges and
recommended details as contained in the current edition of the SMACNA HVAC Duct Construction
Standards. Ductwork shall include supply air, exhaust air, return air, and outdoor air ducts, together with
all necessary fittings, splitters, dampers, quadrants, flexible connections, sleeves, hangers, support,
braces, etc. Hang and install ducts in a neat and workmanlike manner from structural members (not roof
deck) with adequate bracing and cross breaking to prevent breathing, rattling, and vibration.
B.
No flexible ductwork on return, exhaust or outside air.
C.
Install Duro-Dyne locking quadrants and Duro-Dyne end bearings on all splitters and manual volume
dampers located above accessible ceiling and Young #1 regulator, C.P., and Duro-Dyne end bearings
elsewhere.
D.
Duct dimensions shown are net inside dimensions.
E.
Duct Turns: Wherever possible, duct turns shall have a centerline radius equal to 1.5 times the duct
width in the plane of the turn. Vane other duct turns to provide a dynamic loss co-efficient ("C") not
greater than 0.2. No reducing ells or tees to be used.
F.
Duct Sealing: Seal duct seams and joints as noted below. Seal entire circumference of all branch duct
connections, tapping collars and spin-ins. Seal ducts using mastic sealant equal to United Duct Sealer.
1.
Class "A" Seal: Seal all joints and seams and leak test as specified.
2.
Class "B" Seal: Seal entire circumference of all transverse joints, seal all longitudinal joints.
3.
Class "C" Seal: Seal entire circumference of all transverse joints.
GOODWYN, MILLS & CAWOOD, INC.
GM&C PROJECT NO. AHUN130007
DUCTWORK
15840 - 1 of 2
NEW AG SHOP FOR PISGAH HIGH SCHOOL
JACKSON COUNTY BOARD OF EDUCATION
4.
2.2
PISGAH, ALABAMA
Class "D" Seal: Seal corner of transverse joints.
DUCTWORK - LOW PRESSURE:
A.
Ductwork: Low Pressure, Pressure and Seal Class shall include all Supply, Return, Exhaust, and
Outside Air Ductwork: 2" pressure class, Class "B" Seal.
B.
Construct ducts in accordance with SMACNA Duct Construction Standards for pressure and seal classes
noted.
2.3
FLEXIBLE DUCTS:
A.
Flexible duct connectors: A two (2) element spiral construction composed of galvanized steel supporting
spiral and coated woven textile fabric with metal or mineral base, UL listed as Class I Air Duct and
Connector (UL 181) minimum R=6.0.
B.
Flexible connectors shall not exceed 5 feet in length.
C.
Make connections between flexible ducts and other equipment using galvanized steel draw bands with
plated screws and buckles and United Duct seal for high and medium pressure ducts and nylon draw
bands for low pressure ducts.
D.
Factory insulate cold flexible ducts using insulation equivalent to that specified for cold ducts.
E.
Flexible ducts: Thermoflex M-KC, Wiremold 57K, Technaflex 57K, or Flexmaster Type 4M. Submit
sample for approval of any other manufacturer.
PART THREE - EXECUTION:
3.1
INSTALLATION:
A.
Ductwork shall be installed in accordance with manufacturer's recommendations.
B.
See details for mounting instructions and accessories.
END OF SECTION 15840
GOODWYN, MILLS & CAWOOD, INC.
GM&C PROJECT NO. AHUN130007
DUCTWORK
15840 - 2 of 2