Sizes Standard round gravity ventilators are available
in 12, 20 and 24 - inch diameter throat sizes. Other sizes, up
to 48 inches, are available through special orders. 26 gauge
inner and outer bands, rain-shield and base assembly are
assembled with 4 pre-formed baffles into a simple yet sturdy
ventilating unit.
Design
The design achieves a free un-obstructed
flow of ventilation air. The addition of a vertical lift type
damper completes the weather tightness of the unit. The damper
is supported in the open position by 4 strong springs and is
closed by a long pull chain. Damper may be locked in any
position by the use of an optional key type chain lock
(please specify when ordering) Ventilator may be furnished
without damper if desired. However, over-spray or driven rain
may enter the vented space. Ventilator with damper may
function as a smoke exhaust vent by including a fusible link
in the chain operator. Assembly is completed by the
installation of a 4X4 bird screen in the opening between the
inner band and rain shield to resist the entry of birds into
the vent area. |
Installation The base is specifically designed for the final
installation, with specified roof slope; either ridge or
single slope and either flat or mounted into a customer
furnished roof panel.
Base and ventilating unit are
furnished pre-assembled ready for installation. Single slope
bases are mounted directly into roof panel and are placed in
such a way as to prevent
damming.
All vents are furnished standard with white or our galvalume
finish, but are available with special color when specifically
ordered. Installation is by use of standard formed closures,
tape sealant, caulking and fasteners as indicated on standard
assembly drawings. Round gravity roof ventilators are designed
for economical, low volume air movement to ventilate
warehouses, light industrial buildings, attics, lofts and
other buildings requiring gravity relief ventilation. They are
also adaptable for use as discharge heads for mechanical or
forced-air ventilating systems. The volume of gravity air
movement can be controlled by the adjustable damper. The
damper is also effective in controlling water intrusion from
wind driven rain and back draft conditions. When ordering,
please specify roof slope and base type. A wooden crate is
included in the price. |