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The fabrication of ductwork shall be carried out in accordance with HVAC/DW/144, ASHRAE or SMACNA standards. Laboratory Area Ductwork (Chemistry Lab) The laboratory area ductwork including all related accessories for supply/exhaust shall be of PVC / Polyethylene / GRP. Contractor shall submit the material for Engineer’s approval. Material Galvanized Sheet - Hot dip galvanized steel shall be to ASTM-A527-87 standard,

steel shall be of lock forming quality, zinc coating designation Z-27 or equivalent approved standard.

Flexible Ducting - Pre-insulated flexible ducting for the linear diffusers shall be

suitable for low / medium pressure. The inner core shall shield the fiber glass insulation from the air stream. The outer jacket shall be of very tough spirally reinforced multi-layer aluminum laminated construction.

Duct Sealant - Duct sealant shall be non hardening, non migrating mastic or

liquid sealant as compounded and recommended by the manufacturer specially for sealing joint and seams in the duct.

Aluminum - Aluminum alloy sheet shall be easy to form and to join and

shall have extra resistance to moist atmosphere (BS 1470). PVC / Polyethylene/ GRP - Suitable material shall be proposed by the Contractor for

Engineer’s approval. The “UV Disinfector” shall be installed inside Supply Ducts. System Description: The UV system disinfects the effluent by exposing it to a powerful ultraviolet light in a confined space. A flow restrictor ensures that the effluent is exposed to the UV light for a sufficient period of time to complete the disinfection process. A control panel is provided that supplies power to the UV system and has an audible and visible alarm that activates if the bulb fails of the UV current drops below a minimum level. The control panel is housed in a weather proof enclosure and has separate circuit breakers for the UV system and the alarm system. Specifications: Minimum Recirculation Inactivation Rate should be as the following:

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Influenza A virus 99.5 %, tuberculosis 99.5 %, smallpox 99.5 %, parvovirus 99.5 % Recirculation Inactivation Rate is calculated after 8 passes. The Inactivation rate increases marginally after 8 passes Single pass inactivation (sterilization) rates should be as the following Influenza A virus 75 %, tuberculosis 75 %, smallpox 75 %, parvovirus 75 %. Single Pass Inactivation means that the air is exhausted after it is treated and is not Recirculation. Maximum pressure drop at UV lambs installation point 0.015 in H2O. Maximum air temperature increase due to UV lambs 0.25 °C. Results are as at lamp change out time (17,000 operating hours) The high intensity UVC lamps will be of the low-pressure, mercury laden argon-neon type with an internal Alumina coating to reduce solarization. UV Lamps: Location = should be inside the supply duct. The UV intensity for each individual lamp shall not be less than; 270 microwatts per/cm2 at 36 inches for the 24 inch lamps, 290 microwatts per/cm2 at 36 inches for the 30 inch lamps 500 microwatts per/cm2 at 36 inches for the 40 inch lamps; 580 microwatts per/cm2 at 36 inches for the 50 inch lamps; 640 microwatts per/cm2 at 36 inches for the 60 inch lamps. Execution: UV Lamps shall be installed in accordance with manufacturer installation instructions and Drawings. Provide submittal indicating the location of the UV Lamps. Provide clearances for servicing and maintenance.

M.19 MANUAL DAMPERS Damper Quadrants All dampers other than dampers behind registers shall be fitted with substantial locking cast metal quadrants. Quadrants shall be mounted outside the duct in an accessible position. On insulated ducts, the quadrants shall be fastened to bearing plates flush with the outside finish of the insulation.

Volume Control Dampers Manual volume control dampers shall be provided as shown on the drawings or as required additionally for balancing purposes. The dampers shall have sturdy corrosion resistant construction. All dampers shall have multi-leaf double skin aerofoil section opposed blades. Individual blades should not exceed 1200 mm in length or 175 mm in width. Double skin blades shall be made out of minimum 22 gauge galvanized steel sheet. Damper frames shall be galvanized made out of 16 gauge steel sheet.