Mistral MPP274S Installation Manual And User's Manual page 7

Venting requirements

The discharge circuit must vent the air to the outside.

DO NOT terminate the venting system in an attic or other enclosed space such as inside walls.

DO NOT use a wall cap of 4'' (10.2 cm) which is normally used for laundry equipment.

Use metal venting equipment only. A rigid metal pipe is recommended. Do not use a plastic or
aluminum ducts.

The length of the discharge pipe and the number of elbows should be minimal in order to provide
the best performance.
For an efficient and quiet operation:

Do not use more than three (3) 90° elbows.

Ensure that there is a straight section of pipe a minimum of 24'' (61 cm) between the elbows if
you must use more than one.

Do not install two (2) consecutive elbows.

The discharge circuit must include a check valve.

At each juncture of the exhaust system, make sure to seal with clamps.

Using caulking, seal around the exhaust hood to the outside (passing through the wall or roof).

The size of the pipe must be the same throughout.
Air booster
Local building codes may require the use of an air exchange system / extra air supply when using a flow
suction system that exceeds a specified value (cubic feet per minute). The rate specified in cubic feet per
minute varies from one jurisdiction to another. Consult a heating, ventilation and air conditioning specialist
for specific requirements in your local jurisdiction.
Evacuation (exhaust) methods
This hood has been configured to evacuate to the outside through the roof or through the wall. The
discharge system required for installation is not provided. A discharge circuit with circular duct 6'' (15.25
cm) is recommended.
Evacuation through the roof
A
A.
Duct of 6'' (15.25 cm) in diameter
to discharge through the roof
B.
Discharge exit through roof
Make sure the first duct runs is at least 12'' (30.5 cm) before redirecting.
7
Evacuation through the wall
A
A.
Duct of 6'' (15.25 cm) in diameter
to discharge through the wall
B.
Discharge exit through wall