Over the range microwaves can vent to the outside or can recirculate the air.
Can all over the range microwaves vent outside.
Over the range microwaves have a light and fan built into the bottom of the appliance.
Typically there might be a cabinet installed over the microwave and inside that cabinet will be duct work or a soffit above the microwave or a direct wall exhaust.
This eliminates smoke cooking odors moisture and hot air from remaining in the kitchen.
When considering venting in an over the range microwave there are ducted vents and recirculating vents.
Ultimately the goal of the vent is to pull the air from the microwave and deposit it to the outside.
If rectangular ducting please note.
Microwaves are shipped from the factory to vent out the top vertically but can also be vented out the rear horizontally.
In the first example the microwave over the range otr will vent through the manufacturer installed grease or carbon filter then directly through an exhaust port that is ducted to the outside of the structure.
Remove the access plate on the top of the unit in order to reach the motor.
Microwaves that vent to the outside force the air through duct work to the outdoors.
When a microwave is replacing a standard range hood it is usually best to use the existing venting method.
If you have an over the range microwave it should have an exhaust fan that vents to the outdoors.
All over the range spacemaker microwaves can be vented to the outside using an equivalent total of 140 feet of rigid 3 1 4 x 10 rectangular or rigid 6 round ducting.
After the smoke and steam are removed the filtered fan vents the air outside your home or cleans it before releasing it back into the kitchen.