How many Envirofans are necessary for
Use approximately one 56 inch (or 60
inch) curved tip Envirofan for each 2000 square feet of floor space to
destratify heat in buildings with ceilings from 12 feet to 40 feet. For
installations with ceilings above 40 feet, use straight tipped blades
(reversing type fans).
Straight or curved tipped blades?
Curved tip blades are recommended for
mounting heights below 40 feet, and straight tipped blades are recommended for
mounting heights above 40 feet. The curved tip blades spread the air over a
larger floor area, and the straight tipped blades drive the air down towards
How many rows of Envirofans should be
In a building with a steeply pitched
roof, only one row of fans will be necessary, even if the room is over 50 feet
wide, as all of the stratified heat goes directly to the peak. In this case,
space the fans on 30 foot centers to move the additionally required CFM.
Where should the Envirofans be
Break the building or room up into
grids, approximately 35 feet to 50 feet per square, and place one Envirofan
near the middle of each grid. Do not place the fans more than 50 feet apart and
expect peak performance. If the room is more than 50 feet wide, it is
recommended to use two rows of Envirofans.
What type of controls should be used?
Northwest has a full line of controls
that will control from one to twelve fans. In low ceiling, or people oriented
areas (classrooms, offices, stores, churches, etc.) use individual controls. In
high ceiling areas (gymnasiums, warehouses, manufacturing areas) use multiple
When are transformer controls
Transformer controls are recommended
for any low noise application (churches, theatres, school rooms, lecture halls,
etc.) to eliminate any hertz hum which may be audible.
What speed should the Envirofans be
Fans should be run at the highest
speed that does not cause a draft on the people below. This can be achieved
best with the use of an infinite speed control.
How often should the Envirofans be
Fans should be operated full time, 24
hours, 7 days, for the full heating and cooling seasons. The fans will save
energy and typically cost just 5 cents per day to operate.
What are the typical savings from
Typical savings, regardless of
climate, temperature set point, type of fuel, insulation, etc., is 20-30% of
the energy used for heating the area covered by fans.