Generac Power Systems 004709-0 owner manual ‹ 2.2.4 Acoustics, ‹ 2.2.3 Sound Insulating Materials

Section 2 – Installation

Recreational Vehicle Generator

•If constructing a compartment, line the exterior (underside) of the compartment floor with 26- gauge galvanized steel.

•All seams, splices and joints of the compartment walls (unless vapor tight by design) should be caulked to prevent poisonous, flammable or explo- sive vapors from entering the vehicle interior.

NOTE:

Caulking must be done so that the caulking mate- rial will stay in place permanently. Pressing such materials as putty tape onto joints and seams is NOT acceptable. A high quality silicone rubber base sealant is recommended.

•Holes and openings made in the compartment walls to allow for the passage of electrical conduit, conductors, hoses, cables, etc., into the vehicle liv- ing area must be sealed vapor tight with silicone rubber base sealant.

•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.

Figure 2.6 – Types of Lock Seams

DANGER

Do not install any flammable material directly above or around the compartment. Heat, trans- ferred through the compartment structure, may be sufficient to ignite, char or discolor seat cush- ions, fiberboard and other flammable materials. Use approved nonflammable insulating materi- als in high temperature areas.

‹2.2.3 SOUND INSULATING MATERIALS

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.

DANGER

Do not install sound insulation or any absorbent material on the compartment floor interior. Such materials will become soaked with combustible or explosive vapors and

liquids and will become a fire hazard.

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.

•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 "Sound Insulating Materials").

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‹2.2.4 ACOUSTICS

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.