Self-supported Fire Resistant Air Duct

	MANUFACTURER:
	A+B, Russia

1. STRUCTURE DESCRIPTION AND APPEARANCE

The self-supported air duct made of ECOPLAST vermiculite panels is a fire resistant air duct that complies with fire safety requirements NPB 239-97.

The maximum fire resistance of the air duct is at least EI 150 given a 25 mm thick ECOPLAST panel. The layout of the "self-supported air duct" is designed for installing air ducts for general-purpose and emergency smoke removal balanced ventilation systems, local exhaust ventilation and air conditioning systems, industrial ventilation ducts, including various types of flues, and other structures.

No internal sheet-steel duct is required.

2. TECHNICAL SPECIFICATION

3. MOUNTING OF THE "SELF-SUPPORTING AIR DUCT"

Duct blocks are marked out on a prepared "workplace," the upper panel in the stack of ECOPLAST panels, or a workbench. The blocks are cut off with a circular saw or a handsaw.

The blocks of ECOPLAST panels [1] are connected at angles to form a joint, glued with the fire resistant putty [5], and fastened with wood screws [3]. The screw heads should be sunk in the panel by 2-3 mm.

The load bearing element [6], [7] should be selected and reinforced in accordance with project details (Method Statement).

Socket blocks are marked out on ECOPLAST panels. Socket blocks [2] are cut off and fastened on each side of the air duct section with wood screws; the fire resistant putty shall be applied to the socket adjustment place prior to fastening. The fire resistant putty is applied to the socket joint from the inside and the next duct section is inserted into it, to be fastened with wood screws. Individual duct sections may be up to 2,000mm long. The transport and assembly weight should be considered. The cavities in panels resulting from sunken wood screws and seams between panels should be filled with the fire resistant putty.

4. AIR DUCT BARS LOCATION

As a general rule, the tie bar should be located at the duct joint. If this is impossible because of some local factors, the tie bar may be independent of the joint. The following minimum requirements should be considered here:
•  A pair of tie bars is required per each air duct section given a section length of 1,450mm. The "A" distance is arbitrary. As a rule, the length of a section is 1,200mm (the panel width);
•  Two pairs of tie bars are required for air duct sections >1,450 ≤ 2,000mm. The distance between tie bars should be equal.
•  Additional tie bars should be installed if maximum loads are exceeded.

"Self-supported air ducts" may be two or three-sided. The fastening is executed as per the Diagram. Adjacent supporting structures must belong to the same fire resistance category as the "self-supported air ducts." Tie bars should be used to support air ducts if the section is ≥ 600 mm.

Horizontal supporting profiles may not be planked if the "C" distance between the tie bar and the side panel of the air duct is a maximum of 50 mm. In other cases they should be planked.

5. AIR DUCT PENETRATIONS

Since "self-supporting air ducts" can have only insignificant heat-caused linear deformations when on fire, there is no need to take measures, for example, to compensate for strains arising in walls. In view thereof:
•  the space between the wall hollow and the air duct may be filled with a PHOENIX PMO panel(s) and sand and cement mortar;
•  the space between the wall hollow and the air duct may be filled with the FORMULA KP fire protection material.