Maxxair CX242DDWT User manual

INSTALLATION INSTRUCTIONS
FOR
WHOLE HOUSE FANS
Fan Models Only: CX242DDWT, CX302DDWT, CX24BD2SPD, CX30BD2SPD, CX36BD2SPD
Fan Models with Hub: CX242DDWTHUB, CX302DDWTHUB, CX24BDM-2SPDHUB, CX30BD-2SPDHUB, CX36BD2SPDHUB
Read all warnings and instructions before beginning to install this fan.
WARNING –TO REDUCE THE RISK OF FIRE, ELECTRIC SHOCK, OR INJURY TO
PERSONS, OBSERVE THE FOLLOWING:
a) Installation work and electrical wiring must be done by qualified person(s) in accordance with all
applicable codes and standards, including fire-rated construction.
b) Sufficient air is needed for proper combustion and exhausting of gases through the flue
(chimney) of fuel burning equipment to prevent back drafting. Follow the heating equipment
manufacturer’s guideline and safety standards such as those published by the National Fire
Protection Association (NFPA), and the American Society for Heating, Refrigeration and Air
Conditioning Engineers (ASHRAE), and the local code authorities.
c) When cutting or drilling into wall or ceiling, do not damage electrical wiring and other hidden
utilities.
d) WARNING –TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT USE THIS
FAN WITH ANY SOLID-STATE SPEED CONTROL DEVICE.
e) Use this unit only in the manner intended by the manufacturer. If you have questions, contact the
manufacturer.
f) Before servicing or cleaning unit, switch power off at service panel and lock the service disconnecting
means to prevent power from being switched on accidentally. When the service disconnecting means
cannot be locked, securely fasten a prominent warning device, such as a tag, to the service panel.
CAUTION
DOUBLE CHECK FAN BLADES ARE SECURE TO HUB PRIOR TO INSTALLATION.
BLADES CAN BE DAMAGED DURING SHIPMENT AND CAN BECOME A HAZARD
UPON ACTIVATION OF MOTOR!
1. This unit has an unguarded propeller. Do not use in locations readily accessible to people or animals.
2. For general ventilating use only. Do not use to exhaust hazardous or explosive materials and vapors.
3. Carbon monoxide is an odorless, colorless gas that can kill. It may be drawn into the house by operating
this fan if your fuel-burning equipment is not properly maintained, or if you lack adequate attic space.

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Ventamatic, Ltd. | P.O. Box 728, Mineral Wells, TX 76068 ▪ Phone: [phone] ▪ www.MYMAXXAIR.com
INSTALLATION INSTRUCTIONS
VERY IMPORTANT
Please read before attempting installation
The fan and shutter are designed for horizontal installation only—the louvers will not function in the vertical
position.
The wooden fan frame is installed on top of the joists, and the shutters open up between the joists, so the rough
opening will be smaller than the fan frame size.
Fan Size
Shutter Rough Opening (L X W)
24-in.
28”X 26”
30-in.
32 1/4” X 29 1/2”
36-in.
34”X 37 1/2”
Veins run lengthwise in 24-in and 30-in shutters, and width-wise in 36-in shutters
Center vein is stationary to allow no-cut joist installation
*For model CX36BD2SPD –The joist-in method may be used only if the joists are 24” on center, or greater, and if there is enough
space between the involved joists and any walls.
24-in Fans- Requires attic space of at least 1200 sq ft. and 8-10 sq ft. of Net Free Exhaust Area
30-in Fans- Requires attic space of at least 1800 sq ft. and 10-12 sq ft. of Net Free Exhaust Area
36-in Fans- Requires attic space of at least 3000 sq ft. and 14 sq ft. of Net Free Exhaust Area
*When measuring vents for NFA, remember that louvers and screens cut down considerably on the available free air —this can
be factored in by measuring the length by the width of the open vent area and dividing the resulting surface size in half.
DO NOT OVERSIZE YOUR FAN! Additional installation of exterior vents may be required to
provide sufficient Net Free Exhaust Area (NFA) for your fan to operate safely and effectively.
Remember –bigger is not always better with Whole House Fans. A smaller fan that operates
efficiently will always be preferable to a fan that is too big for its application.
Tools and Materials Needed:
•Drill
•1/4” and 1/8” drill bits
•Straight edge ruler (yardstick, 4 ft.
level)
•Pencil or marker
•Circular saw
•Ring shank drywall nails (1 1/2")
•#12D nails
•Adjustable wrench
•Flat head screwdriver
•Phillips head screwdriver
•Safety goggles
•Speed square
•Saber saw, reciprocating saw

Ventamatic, Ltd. | P.O. Box 728, Mineral Wells, TX 76068 ▪Phone: [phone] ▪www.MYMAXXAIR.com
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Deciding on a Joist-In or Joist-Out Installation
Joist-In Installation
The ceiling joists will be left intact for this
method. You will need another attic access, as the
fan will not fit through the shutter opening with
the joist(s) in place.
Joist-Out Installation
This method involves removing one or more
ceiling joists. This is the preferred method, as the
best location does not necessarily coincide with
the position of the joists.
Step 1: Prepare the Shutter Opening
•Find a spot in the center of the hallway, drill a hole
and feed a wire through to mark it.
•Mark space around the wire equal to the area of the
rough shutter opening in the chart below in the joist-
in or joist-out option below.
•Remove all insulation above the installation site.
Joist-In Installation
•Align shutter vein with ceiling joist in the
center of the shutter opening.
•Draw a line on the ceiling marking the rough
opening size of the shutter frame.
•Double-check the accuracy of the dimensions
you have marked and that all the corners are
square.
TIP: Use the shutter as a template to outline the
opening by drawing the cutout line around the
inside edges.
Joist-Out Installation
•Drill two ¼” holes (from attic floor
through the ceiling) at the two corners that are
aligned with one of the ceiling joists.
•On ceiling side, draw a straight line between
the two drilled holes. Use this line as a guide
to mark the other three sides of the shutter
opening, using rough opening dimensions
chart above.
•From ceiling side, drill two more ¼” holes at
the remaining corners.
Fan Size
Shutter Rough Opening (L X W)
24-in.
28”X 26”
30-in.
32 1/4” X 29 1/2”
36-in.
34”X 37 1/2”

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Ventamatic, Ltd. | P.O. Box 728, Mineral Wells, TX 76068 ▪ Phone: [phone] ▪ www.MYMAXXAIR.com
Step 2: Cut the Shutter Opening
•Cut through ceiling along lines using a
circular saw. Measure depth of drywall
and adjust the saw so you only cut the
drywall and avoid the joists.
•Carefully remove the drywall from the
opening
*Note* Make sure the exposed joist is
centered if doing the joist-in installation.
Step 3: Cut the Ceiling Joist (For Joist-Out Installation Only)
•Stabilize the joists using 2 X 6 lumber to
bridge the joist about six inches away from
either side of the opening.
•Attach stabilizers to the joists with #12D nails
or 2 1/2” deck screws.
•Mark two lines on the joists to be cut about
1 1/2” away from either side of the opening.
•Cut along the lines using a saber saw. Make
sure cuts are perpendicular and accurate.
Step 4: Frame the Shutter Opening
•Use lumber of the same dimensions as your ceiling joists and fasten them to the edges of the frame
opening using #12D nails.
•Fasten the sheetrock to the new frame using 1 1/2” ring shank drywall nails.
•Seal any gaps between headers and joists with caulk or foam insulation.
_*Note* Remove the two bridges from the previous step if doing a joist-out installation.______________
Joist-In Installation
Joist-Out Installation

Ventamatic, Ltd. | P.O. Box 728, Mineral Wells, TX 76068 ▪Phone: [phone] ▪www.MYMAXXAIR.com
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Step 5: Facing Installation
•Use 2 X 6 boards to create a square with the inside dimensions being the same distance as the shortest
dimension of the shutter rough opening (i.e. 26” for a 24-in model, etc.).
•Nail or screw in the facing to the framed opening.
TIP: If doing a joist-out installation, use lumber from the support pieces as the long cuts and the removed joists as the
short cuts.
TIP: For a quieter fan, build a second box frame the same size as the fan frame and install it between the frame and
facing. Ensure that there is still a minimum of 36” clearance between the fan blades and attic roof.
Step 6: Prepare and Install Fan Assembly
Belt Drive Models
•Remove hardware and remount the motor on
the top side of the struts.
•Position fan belt on the pulleys and adjust it to
fit snugly with about 1/2” deflection. DO NOT
OVERTIGHTEN THE BELT!
•Tighten fan blade set screw and make sure the
hub of the fan blade assembly is facing up
towards the roof.
Direct Drive Models
•Remove fan blade and wire the motor first.
•Replace and secure the blade so it is about
half-in and half-out of the hub.
•Tighten fan blade set screw before operating
and make sure the hub of the fan blade
assembly is facing up towards the roof.
Joist-In Installation
Joist-Out Installation

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Ventamatic, Ltd. | P.O. Box 728, Mineral Wells, TX 76068 ▪ Phone: [phone] ▪ www.MYMAXXAIR.com
Step 6: Prepare and Install Fan Assembly (cont.)
•Push fan assembly through the shutter opening diagonally or through another attic access if doing
a joist-in installation.
•Place frame on top of facing or additional frame and draw alignment marks around the base of the
assembly then secure to the facing using screws.
Step 7: Install the Shutter
_*Note* Never operate the fan without the
shutter installed
•Draw alignment marks on the ceiling 7/8”
from the edges to indicate the outer edges of
the shutter frame.
•Install the shutter using the white-headed
wood screws provided with your fan.
•Caulk the seams for an airtight seal.
Step 8: Wiring Instructions
*Note* All wiring supplies and installations must meet or exceed the requirements of local electrical
_and fire codes. Wire to 120 Volt, 60 Hz circuit only, using 14-3 two-conductor wiring with ground.
•Disconnect the power supply or switch off the appropriate circuit breaker.
•Install included switches in a double gang UL listed wiring box, in a wall close to the fan.
•Connect incoming power supply wire (BLK) to the top right terminal of the On/Off switch (1).
•Connect bottom right terminal of the On/Off switch (2) to the bottom right terminal of the High/Low
switch (3) using a jumper wire.

Ventamatic, Ltd. | P.O. Box 728, Mineral Wells, TX 76068 ▪Phone: [phone] ▪www.MYMAXXAIR.com
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Step 8: Wiring Instructions (cont.)
•Connect High speed motor lead (BLACK) to the top right terminal of High/Low switch (HIGH).
•Connect Low speed motor lead (RED) to the bottom left terminal of High/Low switch (LOW).
•Connect incoming common wire (WHT) to the common wire (WHITE) from the motor.
•Connect incoming ground wire (GND) to the grounding screw on each switch (4, 5) and to the ground
screw (GROUND) in the motor box.
•Manually rotate fan blade to ensure no obstructions before turning on the power to the fan.
Operating Instructions
Whole House Fans cool your home by pulling in fresh, cooler air from outside through open windows and doors.
For best results in a multi-story home, windows should be opened on alternate levels for most efficient cooling.
NEVER operate fan without open windows or doors.
CAUTION: If your home has a fireplace, be sure that the flue damper is closed to prevent chimney soot
from being drawn into the house by the fan. DO NOT operate the fan when a fire is burning in the
fireplace. Common Installation Issues
Motor Stops after 10-20 Minutes
•A tight belt tension can cause the unit to overheat.
•Insufficient intake or exhaust Net Free Air. Open more doors and windows or increase the amount of ventilation in
the attic.
•Check the bearing assembly for resistance on belt driven models to ensure there are no rough spots.
Unit is Noisy
•If the unit is considered to be too noisy in general, install the additional frame between the fan and mounting frame.
•Large fans will make noise while operating. Moving the fan further into the attic will reduce the apparent noise.
Make sure you still have 36” of clearance to the roof.
•Make sure all screws and bolts are tightened.
•Ensure enough clearance above the unit, minimum of 36” from fan blades to roof.
•Verify Exhaust NFA. Inadequate NFA will result in the unit working harder and making more noise.
Not Enough Airflow
•Verify NFA intake and exhaust requirements are being met. Lack of airflow can be the result of lack of fresh air and
lack of ventilation to expel the air. Try channeling the air by opening only doors and windows in a certain area to
funnel the wind flow.
Shutter is Hitting the Fan
•Check to make sure there is enough space between the louvers and the fan. There should be around 6”-7 ½” between
the fan blade and the vent.
Fan Does Not Start on Low Speed
•Verify that the fan will start on High Speed. Switch to Low Speed from the High setting. For additional
troubleshooting, please contact our customer support team.

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Ventamatic, Ltd. | P.O. Box 728, Mineral Wells, TX 76068 ▪ Phone: [phone] ▪ www.MYMAXXAIR.com
VENTAMATIC, LTD.
LIMITED WARRANTY
This warranty is underwritten by Falco Insurance Company and is extended to the original retail purchaser of this model or, if this unit
is purchased and requires installation by a building contractor, to the original owner of the home. No subsequent purchaser of the unit
or of a home in which it is installed is entitled to any of the benefits of this warranty.
This product is warranted against defects in materials and workmanship for the time period listed by model number below, from the
date of original retail purchase. No other parts or components are warranted. There is no warranty for defects caused by abuse, faulty
installation, or the like.
CX242DDWT, CX302DDWT Limited 10-Year
CX24B2SPD, CX30BD2SPD, CX36BD2SPD Limited 10-Year
Repairs or replacement parts supplied under this warranty are warranted only for the period of this warranty; that is, for the time
period stated by model number above, from the date of the original retail purchase of the unit.
In the event of a defect or malfunction, we will replace or repair the defective part or component only and return the new or repaired
part to you freight prepaid.
You must bear all other expenses incurred in obtaining repairs, including labor required for field repair or replacement, and the cost of
shipping the defective part to us. You must also bear the cost of repair to or replacement of any part or component and the shipping
charges incurred for the repair or replacement and return to you of any part or component not covered by this warranty, including parts
or components damaged by you.
The company reserves the right to demand and receive written evidence of the date of purchase before undertaking its obligations
under this warranty. The right to demand and receive written evidence of date of purchase extends to all licensed dealers of
Ventamatic, Ltd. products.
You should, therefore, retain your sales slip and attach a copy of it to the warranty claim.
To start a warranty claim you must:
Contact Ventamatic, Ltd.
An RGA (Returned Goods Authorization) form is required for returns to the factory to ensure your return can be processed efficiently
and quickly. Please contact Ventamatic, Ltd. toll-free at 800-433-1626 or via web at www.MYMAXXAIR.com to obtain an RGA and
follow the instructions given. There is no informal dispute settling mechanism available in the event of a controversy involving this
warranty.
Any and all implied warranties which may exist terminate upon the expiration of this warranty from the time period listed by model
number above, from the date of the original retail purchase. Some states do not allow limitations on how long an implied warranty
lasts, so this limitation may not apply to you.
Ventamatic, Ltd. is not liable to you for incidental or consequential damages arising out of defect or malfunction of a unit or its
installation or out of any alleged breach of this warranty. Some states do not allow the exclusion or limitation of incidental or
consequential damages, so this limitation may not apply to you.
This warranty gives you specific legal rights and you may also have other rights which may vary from state to state.
rev.4/19