If you’re considering installing a new over the range (OTR) microwave or looking to upgrade your existing one, you may be debating whether or not to vent it to the outside. OTR microwaves have a built-in ventilation system that can either recirculate the air back into your kitchen or be ducted outside. Venting your OTR microwave’s exhaust outdoors has some great benefits, but also comes with extra installation considerations.
How Over the Range Microwave Vents Work
All OTR microwaves have a venting system underneath the actual microwave oven housing. This system uses a fan and filter to remove smoke, steam, odors and grease from cooking. The vent pulls air upward from the cooktop below through the vent and either recirculates it back into the kitchen or vents it outside through ductwork.
In a recirculating over the range microwave, the vent fan pulls the air through a filter to trap grease and odors before releasing it back into the room. Ventless microwaves require less installation work, but aren’t as effective at removing contaminants and moisture.
In contrast, an exterior vented OTR microwave ducts the air directly outside through a system of pipes and vents. This removes humidity, fumes and particulate from cooking out of the home entirely. However, venting to the outside requires installation of ductwork and an external vent.
Benefits of Venting an OTR Microwave Outside
There are several compelling reasons you may want to vent your over the range microwave to the exterior:
- Eliminates cooking odors – Venting outside removes grease particles and food smells from the kitchen.
- Improves indoor air quality – Venting cooking pollutants out keeps the air in your home cleaner.
- Reduces moisture and humidity – An external vent eliminates steam and moisture from cooking.
- Prevents grease buildup – Ducting grease to the outside prevents sticky residue buildup inside.
- Allows for higher-powered ventilation – External vents can output more CFM for stronger ventilation.
For many homeowners, the enhanced air purification and odor elimination an exterior vent provides makes it well worth the extra installation effort.
Considerations Before Venting an OTR Microwave Outside
While venting your over the range microwave outside has definite perks, there are also some downsides to weigh:
- More expensive installation – Venting requires ductwork and an external vent, raising costs.
- Changes to exterior wall – A hole must be cut and vent installed on an outdoor wall.
- Potential for noise – Ducted fans and high airflow can create more noise.
- Greater energy use – Conditioned air is lost through external venting.
- Temperature variations – Venting air to the outside may increase cooking time.
Carefully measure the pros and cons before deciding. An exterior vented microwave costs more upfront and impacts your home’s exterior. But for many, the kitchen and indoor air quality benefits outweigh the downsides.
What’s Required to Vent an OTR Microwave Outside
Proper installation is key to ducting your over the range microwave outside. Here are the main components your contractor will need to install:
- Ductwork – Rigid metal ducting will need to be run from the microwave vent to the outdoor vent location.
- Exterior venting – A weatherproof cap vent must be installed on the exterior wall.
- Wiring – Any electrical modifications to support an exterior vented microwave.
- Openings – Cut openings in walls/ceilings are needed for ductwork.
- Sealing – All ductwork connections must be well-sealed.
Installation isn’t straightforward, so professional installation is recommended unless you’re an experienced DIYer. Proper ducting is key to maximize ventilation airflow and efficiency.
Installation and Venting Options
There are a few different ways your over the range microwave can be vented outside:
Professional Installation
Hiring an experienced contractor is the easiest but most expensive option. They have the skills to install ducting and vents properly. Many charge $300 to $600 in labor costs, not including materials.
DIY Installation
With proper planning and research, DIY venting installation is possible. You’ll save on labor, but it’s a complex project requiring HVAC and construction skills.
Through-Wall Venting
Ducting through an exterior wall near the microwave is the most direct venting approach. This limits duct length and bends.
Venting Through Roof
If side wall venting isn’t feasible, ducting vertically through the roof is an option. This requires attic access and weatherproof roof venting.
Condos and Apartments
Multi-family units often don’t allow exterior venting modifications. Check condo bylaws before planning microwave venting.
Estimated Costs of Venting an OTR Microwave
Total costs to vent your over the range microwave outside can range quite a bit based on your ducting route and labor choices:
- DIY: $200 to $500 for materials
- Contractor install: $500 to $1,500 total
A shorter, simpler ducting path will put you on the lower end of the price range. Complex ducting routes, roof venting or issues requiring HVAC modifications can increase the cost.
Step-by-Step Guide to DIY Installation
With proper planning, tools and skills, it is possible to install over the range microwave ducting yourself as a DIY project and save on labor costs.
Carefully follow the microwave manufacturer’s venting specifications for duct sizing and maximum vent lengths during DIY installation.
Tips for Proper Venting
Once your over the range microwave is externally vented, follow these tips for proper operation:
- Always use ventilation fan when cooking to remove fumes.
- Clean filters monthly to maximize airflow.
- Check that dampers are fully open.
- Inspect ductwork and vent for damage or leaks.
- Hire an HVAC pro for annual vent inspection.
Routine maintenance keeps your ventilation performing optimally. Monitor cooking times and ventilation power after installing an exterior vented microwave.
Alternatives to Exterior Venting
If you ultimately choose not to vent your over the range microwave to the outside, you still have options to reduce odors and humidity:
- A high-quality charcoal filter for recirculating microwaves.
- Install a ventless range hood over the cooktop.
- Use a downdraft ventilation system.
- Install a standard microwave with vent under the cabinet.
While these won’t remove air contaminants as effectively, they provide ventilation with simpler installation. The choice depends on your kitchen layout, venting priorities and budget.
Venting your over the range microwave to the exterior provides optimal ventilation, but comes at a higher upfront cost. For many homeowners, the pricier but more effective ducted venting is worth it for enhanced air quality, odor removal and humidity control. Assess your needs, budget and kitchen layout carefully when deciding on exterior venting. With proper planning and execution, you can successfully reap the benefits of an exterior vented microwave.