McGill AirFlow Uni-Housing enclosures are an excellent choice for enclosing many types of HVAC equipment for both pressurized and nonpressurized applications. They are designed for low leakage, provide excellent thermal and acoustical control, and facilitate easy on-site assembly for indoor or outdoor applications. And depending on the application or size of the enclosure, McGill AirFlow can deliver the finished enclosure or the subassemblies to the jobsite.

Uni-Housings can be constructed from McGill AirFlow's Type SL or Type TG acoustical panel systems. The Type SL and Type TG panels are identical except for their panel joint designs. The Type SL panel has a self-locking (snap-lock) design that offers quick assembly and is used in applications where disassembly is not a primary concern. The Type TG panel has a simple tongue-and-groove design that is recommended when future disassembly and re-erection of the enclosure may be required. Both panels have a sandwich-type construction consisting of a solid galvanized steel outer shell, acoustical/thermal insulating fill, and a perforated inner liner of galvanized steel. All of the standard wall, door, roof, and floor panels are available with either the snap-lock joint design or tongue-and-groove joint design.

A special built-in connection system allows the Type SL panels to snap-lock together, forming a low-leakage, structurally sound, full-length joint. This mechanical interlocking joint requires no sheet metal screws. The three-step panel locking sequence shown illustrates the snap-lock action of the connection. First, one panel is started into the structural channel of the next panel. As the panels are pushed together, the locking lugs spring out and then snap back into position as the connection process is completed. Sealer, which is placed in the outside panel groove prior to connection, is hydraulically extruded in place as the panels are snap-locked together.

The Type TG panels utilize a tongue-and-groove joint design where the tongue end of one panel slips into the groove end of the adjoining panel. Fasteners (screws) are required for securing the panel joint. For installations where disassembly and re-erection may be required, it is recommended that a removable joint sealer be used instead of the standard McGill AirSeal United Duct Sealer™ sealant.

Both SL and TG panels are available in a standard 4-inch thickness. A 2-inch thickness is optional, with other thicknesses available by special order. Standard panel widths are 24 inches and 36 inches, with standard lengths up to 12 feet. Other widths and longer lengths are also available through special order. For most enclosures, at least one special-width panel will be required as a fill-in panel to match the specified dimensions of each wall, floor, or roof assembly. Also, in most cases, maximum panel lengths will be determined by the working design pressures.

The standard material for both the outer shell and inner liner is galvanized steel. It can be specified as either solid or perforated and has a minimum G-60 zinc coating. The perforated steel has 23 percent open area. Many different material and gauge combinations of outer shell and inner liner can be selected, with the inner liner being either solid or perforated.

The standard acoustical/thermal fill material used in Type SL and Type TG panels is 1.55 pcf fiberglass, giving the standard 4-inch-thick panel an R17 value. The fill will not settle or promote the growth of bacteria, mold, vermin, or insects. A moisture barrier can also be specified. This consists of one layer of polyethylene plastic separating the insulation from the inner perforated metal liner.

A special built-in connection system allows the Type SL panels to snap-lock together, forming a low-leakage, structurally sound, full-length joint. This mechanical interlocking joint requires no sheet metal screws. The three-step panel locking sequence shown illustrates the snap-lock action of the connection. First, one panel is started into the structural channel of the next panel. As the panels are pushed together, the locking lugs spring out and then snap back into position as the connection process is completed. Sealer, which is placed in the outside panel groove prior to connection, is hydraulically extruded in place as the panels are snap-locked together.

Double-wall (insulated) acoustical enclosures shall be provided as specified on drawings. All panels and components shall be prefabricated and supplied by a nationally-recognized manufacturer with published standards of construction, assembly, and technical performance. The manufacturer shall have produced a standardized, prefabricated panel system for at least 10 years. Construction and performance of the installed system and components shall conform to all specifications listed in this document. The system and components shall not be susceptible to damage from extended exposure to airflow, pressure differentials, vibration, air temperature, or humidity.

Enclosure panels shall have either a snap-lock joint construction or a tongue-and-groove joint construction. Panels with snap-lock joint construction shall be such that adjacent panels are held together rigidly with an integral, continuous, self-locking joint on both inside and outside panel surfaces. Panels with tongue-and-groove joint construction will be held together with fasteners such as screws. Neither panel types should require H-connectors, tape, or any other type of additional connectors.