Guardian Technologies 04164-3 Manual De Usuario

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If flexible metal conduit is used, it must be sealed 

internally at the end where it terminates inside the 
compartment’s electrical junction box. 

NOTE:

Flexible metal conduit, due to its unique construc-
tion, is NOT vapor tight along its entire length.

Seams and joints of the galvanized steel (whether 

used as a liner or for the compartment itself) must 
be lapped and mechanically secured. Such seams 
may be manufactured, welded, bolted, riveted or 
screwed. Manufactured lock seams are shown in 
Figure 2.6. Installer constructed compartments 
typically utilize a standard lap joint.

After the compartment has been metal lined and 

vapor sealed, line the compartment interior walls 
and ceiling with an approved, nonflammable sound 
insulating material. See the "Sound Insulating 
Materials" section.

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Once installers have determined that a compartment 
is properly constructed and metal lined, they can add 
acoustical material. This may include additional seal-
ant or insulating material, to reflect noise away from 
the vehicle interior.

Sound insulating materials should be of a nonflam-
mable type. One excellent insulating material is a 1-
inch (25 mm) thick fiberglass having a 2-pound den-
sity. When fiberglass is used, its coated side should 
face toward the compartment interior.

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Using a combination of sound insulating materials 
can often reduce noise more effectively than a single 
material. For example, a sheet of lead or visco-elastic 
material, along with a layer of other acoustical mate-
rial, is more effective than when a single material is 
used.

For additional noise abatement, the installer may 
wish to consider the following:

Using special sound insulating materials.
Construction of a special noise abatement com-

partment.

NOTE:

Any method used to reduce noise must not 
adversely affect the flow of cooling and ventilating 
air into or out of the compartment.

In addition to the effective use of sound insulating 
materials, construction of a special noise abatement 
compartment might be considered to reduce noise 
levels. Such a compartment might be constructed as 
follows (Figure 2.7):

Use 5/8-inch thick or 3/4-inch thick plywood in the 

compartment.

Construct the compartment floor of a double thick-

ness of 5/8-inch or 3/4-inch plywood.

Line the compartment interior walls and floor, as 

well as the underside of the floor, with 26-gauge 
galvanized steel.

Vapor seal all compartment seams and joints.
Over the galvanized steel lining, install a combina-

tion of acoustical materials as mentioned in the 
"Sound Insulating Materials" section.

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Seal all compartment door edges to prevent noise 

leakage around the door perimeter.

Line the compartment door interior (except for air 

openings) with suitable, fireproof sound insulation 
(such as 1-inch (25 mm) thick fiberglass with a 2-
pound density).

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