Just like other cooking gadgets that generate a ton of heat all convection microwaves require ventilation to ensure there is heat expulsion. Failure to which microwave efficiency may be compromised due to malfunctioning.
It is common knowledge that excessive heat can damage the component of any electronic gadget and cause to stop working as it should.
How much clearance does a microwave need?
Clearance space may vary depending on the type of microwave and the manufacturer; below is the recommended microwave ventilation clearance for different types of microwaves;
Countertop models
These require;
- 3″ of clearance on both sides and the top
- 1″ clearance in the rear
The front edge of the microwave (measured at door) should sit at least 3″ or more back on the counter or shelf to avoid accidental tipping.
If located on the counter near a range, we recommend locating it at least 2 ft away.
Note:
- Do not place near or over a heat source.
- Do not remove the feet of the microwave, as it can affect air circulation and make the microwave less stable.
- Do not place cookbooks, small appliances, or other items on top of the microwave.
Over-the-range model
Over-the-range microwaves models are installed between cabinets, and can be installed against a wall. They do not require air clearance on the sides. However, some models may require 1/2″ clearance on the hinge side for the door to open.
This model can be installed under a cabinet, even if there is not a cooking surface underneath. The height clearances must still be met.
Note: Remember to look for installation instructions or Quick Specs for your model.
Clearance range
- Over the range models must be installed 66″ from the floor to the bottom of the cabinet that the microwave attaches to. This can also be measured as 30″ from the cooktop to the bottom of the cabinet it attaches to.
- There is a minimum and maximum cabinet depth. Refer to the installation instructions for your model.
- Over-the-range microwaves cannot be used on a counter or shelf. The underside is not flat and would not provide a stable surface. Additionally, there can be a heat issue, especially if the vent fan or surface lights were accidentally turned on.
Note: Do not install in a closed cabinet or cut-out space where the bottom is covered.
Countertop models with optional hanging kit
Some countertop models offer an optional Hanging Kit, which will be listed in the features or accessories for that model.
Installation with Hanging Kit:
- Follow the installation instructions provided with the hanging kit. Installation in a 12″ deep cabinet is strongly recommended.
- Do not install directly against a side wall or cabinet.
- Allow 2″ air clearance on each side of the microwave.
- No additional air clearance is required in the rear beyond the included spacer/rear brackets.
- If the model has removable rubber feet, they may be removed.
- If installed in a cabinet with the hanging kit, allow 2″ on each side and at the bottom.
Microwave ventilation requirements for countertop models are;
- 3″ of clearance on both sides and the top
- 1″ clearance in the rear
- The front edge of the microwave (measured at door) should sit at least 3″ or more back on the countertop or shelf to avoid accidental tipping.
- If located on the counter near a range, we recommend locating it at least 2 ft away. Do not place near or above a heat source.
- Do not remove the feet of the microwave, as it can affect air circulation and make the microwave less stable.
- Do not place cookbooks, small appliances, or other items on top of the microwave.
Hanging Microwaves models
These are microwaves mounted under a cabinet with an optional hanging kit
- 2 inches on each side.
- 2 inches underneath.
How to ventilate an in cabinet microwave oven
Ensure to read manufacturer instructions and purchase all of the duct work needed to before you start. Most manufacturers provided detailed instructions that will help you to install a vented microwave oven. Follow these steps for in cabinet microwave ventilation;
Microwave Venting Options
Microwave ovens can be vented in three different ways. Exterior venting models the following three types of ventilation:
- Outside Top Exhaust (Vertical Duct)
- Outside Back Exhaust (Horizontal Duct)
- Recirculating (Non-Vented Ductless
Venting to The Outside
If your microwave oven requires outside ventilation, you will need to install an exhaust duct with a vent hood. Most hood exhausts have been designed to mate with standard 3 1⁄4′′x 10′′rectangular duct.
If a round duct is required, a rectangular-to-round transition adapter must be used. Note – Do not use less than a 6′′diameter duct as velocity will be restricted.
How to prepare the Vent Hole In Wall:
- Place the template or mounting plate against the rear wall and locate and size of the wall cutout for the rear wall duct depending on the microwave oven placement.
- Use a saw drywall saw to cut out the opening.
- If a wall stud is in the way use a reciprocating saw to remove that section. Or look into diverting the duct which is better than messing with studs as they could be load bearing.
- Cut the exterior hole in the wall and remove any siding necessary to install your exterior vent hood.
- Most microwaves are shipped assembled for top exhaust.
- You will need the exhaust adapter for installation in the rear wall opening.
- To remove the exhaust adapter from the microwave remove tape securing damper.
- Fit the exhaust adapter into the house duct as per the instructions in your user manual.
- Make sure the exhaust adapter is lined up with the house duct and lines up with the holes in the mounting plate.
- Line up microwave to duct and connect by placing it on the wall bracket or connecting bolts above. This usually takes two people.
- Install exterior vent hood.
- Use 3M flashing tape or Vycor, or Tyvek tape to ensure that water will not enter the building envelope.
- Re-install trim or siding.
Note: If your microwave does not require outside venting simply leaving the recommended amount of clearance space will do the job.
Safety Precautions for Microwave Oven Installation
Here a few safety precautions to keep in mind during installation. to ensure that your microwave oven operates properly.
- Place the microwave oven at the right height.
- The microwave oven should be easily accessible and within reach of those operating it. The door should not be higher than your face.
- You should not have to stretch to place or remove things from the appliance.
- If it is placed too high, hot food or liquid can spill and cause accidents.
- Always place the microwave away from inflammable objects.
These include;
- Wood
- Cloth
- paper.
- When installing an over-the-range microwave oven, leave enough room to work comfortably on the stovetop.
- Leave a gap of at least 30 inches between its bottom and the stove to reduce the risk of burns and accidents.
- Use the vent on the underside of the oven to vent the stove when it gets too hot.
What Happens if You Don’t Ventilate a Microwave Oven?
Lack of proper venting may cause your microwave to malfunction. This is because the lack of circulation will prevent dissipation of hot air. Which may cause the microwave to start overheating and breakdown over time.
Excess heat will over time damage components of the microwave. Additionally, if the microwave is notable to intake cold air it will not be able to cool down as it is designed to do. this can lead to poor operation.
Do All Microwaves Have to be Vented?
Yes. Microwaves need adequate ventilation on each side and the the rear and the top to function properly. This allows for good circulation of air; which is crucial for the intake and discharge of air.
However, some manufacturers may recommend not venting if on all sides depending on whether the side is covered or exposed. Additionally, some microwaves boast built-in ventilation systems.
Check this too: Can Microwave Ovens Explode?
Over-the-range microwave venting is crucial for microwaves that have an exhaust fan units mounted on top of them. The fan serves as the exhaust for the stove underneath.