sheet metal work for duct heat ventilation air conditioning

 sheet metal work for duct heat ventilation air conditioning

sheet metal work for duct heat ventilation air conditioning www.hvacmepcontractors,com

A. All duct runs shall be checked for clearances before installation of any ductwork. higher than decorated ceilings, duct locations and elevations should be co-ordinated with work of different trades to avoid conflicts with structure, piping, passage and light-weight fixtures.

B. Duct construction shall be in accordance with best practices and latest ASHRAE or SMACNA needs for metal gauges, joints, reinforcing and supports.  All exposed ductwork shall be created and decorated to produce a neat, smooth, finished look. Cd plated sheet screws shall be used on all exposed ductwork.  Ducts shall be free from thumping or rattling once fans ar turned on or off.

C. Duct sizes shall be sized by the Contractor exploitation zero.04” pressure drop except that duct shall be offset PRN to clear structural members and to co-ordinate with different trades and should meet the newest ASHRAE and SMACNA standards.

D. the middle line radius of all duct elbows  shall be a minimum of one and half times the dimension of the duct. wherever building conditions don't yield this radius or wherever sq. turns ar shown, factory-made double walled duct turns capable Aero-Dyne or Tuttle & Bailey shall be utilized in the provision or exhaust air ducts and "Sonotru" natural philosophy attenuating turns as factory-made by South management product Co. shall be utilized in any air ducts wherever natural philosophy insulation is enclosed.

E. Duct sections 1'-6" wide or less shall be butted along and articulated  with flat drive cleats 2-1/8" wide. prime and bottom cleats shall be cut flush with duct and facet cleats bent over to form a good joint.  Standing bar slips as given for ducts over 18" is also used at the Contractor's choice.

F. Ducts from 18" to 30" wide shall be articulated  with 1/2" standing bar slips product of metal a similar as or heavier than duct sheets.  Joints in ducts with either dimension over 30" shall have 1" standing bar slips on those sides over 30". wherever sides ar over 42", the standing bar slips are bolstered with one one/2" x 1 1/2" x 1/8" angles. further angle stiffeners not over 60" apart shall be provided between joints.  Ducts over 60" broad shall be articulated  with one 1/2" x 1/8" angle irons riveted to ductwork on all sides with 1/8" rivets at less than four 1/2" on centers, sections locked with 3/16" stove bolts at not over 6" centers, sheets turned over angles into joint a minimum of 1/4".

G. sheet screws 3/4" #10 is also wont to attach filler angles to ductwork to secure seams, spaced not over 12" on centers and not but 2 per facet of 12" or a lot of, except wherever given otherwise.  Button punching shall not be used apart from pre-erection attachment of fittings.

H. give hinged galvanized steel access and examination doors opposite every manual damper, at every fireplace damper, and at each duct mounted management device.  Doors shall be capable Buensod-Stacey kind S-2 of rigid construction with forged kind rotary latches. wherever area limitations don't yield full swing of the gate, 2 rotary kind latches shall be used.  Doors settled in insulated ducts shall be furnished  extended frames to function a stop for insulation.  Insulate doors settled in insulated ductwork.  All doors shall be gasketed.  Door shall be 10" by 12" minimum except wherever restricted by duct dimension and shall be larger wherever necessary for access to fireplace damper liquified links or different devices.

I. Hangers for all rectangular ducts four sq. ft. in space or higher than shall be spherical bar kind fixed to one one/4" x 1 1/4" x 1/8" angles below the ducts.  Ducts but four sq. ft. in space shall be decorated with black 1" x 1/16" strap iron bent 1" below bottom facet of the duct and fixed to the duct with sheet screws, exploitation not but 2 screws per facet and as more so they're not bigger than 6" centers.

J. Hangers ar to be placed on not bigger than 8' 0" centers or nearer wherever needed so the ductwork will support the load of a person at any purpose.  

www.hvacmepcontractors.com sheet metal work for duct heat ventilation air conditioning

K. where sound insulation lining is employed, the sheet duct size should be increased  to produce the clear within dimensions or cross sectional space needed.

L. Duct joint waterproofing, reinforcing, flanges, etc. for rectangular sheet ducts shall be supported maintaining airtight ducts at two 1/2" WG most static pressure with most discharge of fifty of total fan capacity; 1/2 of I Chronicles for spherical and oval ducts.  All joints in ductwork shall be sealed with U.L. classified hardcast United Duct Sealer, or equal.

M. Duct systems shall have ample volume dampers to regulate and modify the entire volume of every system, each zone, in every branch and at every diffuser or grille.  Volume dampers shall be of the butterfly kind with eighteen gauge atomic number 26 blade.  All dampers shall be equipped with Duro-Dyne kind UNXLD protection quadrant.  All dampers shall be given damper bearings on every finish of shaft mounted on a 2" x 3" x 1/8" plate command to duct with sheet screws. most dimension of single blades shall be 14".  Splitter dampers shall not be used.

N. give fireplace and/or smoke dampers with a UL label for not but one 1/2 hour fireplace protection rating in accordance with UL-555 continued examination service.  Blades Associate in Nursingd frame shall be galvanized steel construction with blades of an interlocking style, having 2 folded-up guides that function stops. liquified links shall be capable Grinnell Fig. 1351, 20 pounds, issue A.  Dampers shall be put in consistent with latest edition of NFPA-90A, mounted with one-1/2" x 1 1/2" x 1/8" returning angles on each side of partition, wall, or floor, and sleeves as per the UL check below that the damper fireplace rating was obtained.