PRV Power Roof Ventilators provide clear evidence of the continued leadership of Canada Blower in the area of ventilating fan packages for industrial and commercial ventilation. Canada Blower supplies axail hooded fans covering sizea ranging from 12" to 120" wheel diameters with capacities from 2000 CFM to 200,000 CFM, and heating capacity up to 4,500,000 BTU/hr.
Axial Exhaust Power Roof Ventilators are factory assembled package fan / blower units constructed to withstand hurricane winds. Its construction incorporates mushroom fan head, or hood head with bird screen, which is hinged to a box-style stack, supplied with access door. For higher capacities stack can be substituted with tubeaxial, or vaneaxial fan. Curb caps are welded to the curb side of the stack. Fan panel assembly is located near the top. Backdraft stack dampers are standard option. Disconnect safety switch is mandatory for roof mounted units.
Axial Supply Hooded Power Roof Ventilators are offered with optional filter rack and filter package protected by bird and insect screen. Motorized back draft dampers are standard on all supply air fans. Filtered mushroom fan head features channel type filter racks, bird screen, hinged connection to the stack box. Special coatings are available upon request.. Fan panel is of double orifice design to allow for supply/exhaust, or reverse-flow operation. Discharge diffusers are available in variety of styles.
Make-Up Air Roof Ventilators are available with direct gas fired heater, or steam/hot water coil packages. Seven arangements are available for efficient control of the air flow in various modes on operation: fresh air /return air /by-passs air, in various mounting arrangements.
FRP Construction - Fiber Reinforced Polyester corrosion resistant construction is available for all hooded power roof ventilators along with protective coatings for corrosive exhaust fumes, or atmosphere, including synthetic vinyl plastic and cathalytic epoxy coatings.
Corrosion resistant construction and
chemical duty construction: for corrosive environment all fans are
avaialble in 304 SS, 316 SS, or 316 L stainless steel construction.
Spark resistant construction is available in all aluminum construction;
wheels are made of special alloys for non-sparking airtsream
Engineering sales of air knife blowers, blow off fans, stainless steel fans and SST blowers, spark resistant ventilators, combustion blowers, vane axial / tube axial blowers, high pressure ventilators, sealed blowers and fans, FRP fiberglass ventilators.
The driving force for the stack effect Pressure difference ( ?P ) is the driving force: Where: ?P = available pressure difference, in Pa
C = 0.0342 a = atmospheric pressure, in Pa
h = height or distance, in m
To = absolute outside temperature, in K
Ti = absolute inside temperature, in K
The equations apply only to buildings where air is both inside and outside the buildings. For buildings with one or two floors, h is the height of the building. For multi-floor, high-rise buildings, h is the distance from the openings at the neutral pressure level (NPL) of the building to either the topmost openings or the lowest openings.
Benefits of Stack driven ventilation:
It does not rely on wind and can take place on still, hot summer days when it is most needed. It is a natural occurring force (hot air rises) and relatively stable air flow (compared to wind) method. Limitations of stack driven ventilation: It has a lower magnitude compared to wind ventilation and relies on temperature differences (inside/outside).Design restrictions (height, location of apertures) may incur extra costs (ventilator stacks, taller spaces).
Chicago Blower Canada PRV Power Roof ventilators provide clear evidence of the continued leadership of Buffalo Fan Canada in the engineering development and manufacture of ventilating fan packages for industrial and commercial ventilation.