Over the Range Microwave Venting Methods to Consider

When selecting a new over the range (OTR) microwave, one of the most important decisions is choosing the right venting method. Proper ventilation is crucial for removing smoke, steam, odors and excess heat from the kitchen during cooking. OTR microwaves offer two main venting options: recirculation or exterior ventilation.

Understanding the pros and cons of each method is key to picking the best system for your needs and kitchen layout.

Recirculating Vents

Recirculating, or ductless, vents feature an internal fan system that draws cooking fumes and air into the microwave through filters. The air then circulates back into the kitchen instead of being released outside.

Pros of Recirculating Vents

• More affordable since no exterior ductwork is required
• Easier to install, usually as a simple drop-in replacement
• Ideal for apartments or houses where venting to the outside is difficult

Cons of Recirculating Vents

• Less effective for removing smoke, grease, and odors
• Potential moisture build-up without exterior ventilation
• Require regular filter replacement for optimal performance

When shopping for models with recirculating vents, pay attention to the CFM rating. Higher CFM means more air circulation power. Look for removable, dishwasher-safe filters for easier cleaning and maintenance.

External Vents

Exterior, or ducted, ventilation systems use ductwork to guide cooking exhaust from the microwave to the outdoors. This removes heat, smoke, and odors from the kitchen for a fresher indoor environment.

Pros of External Vents

• More effective at removing airborne grease and odors
• Helps maintain proper indoor humidity levels
• No replacement filters needed

Cons of External Vents

• Installation may require wall or roof modifications
• Potential for heat or cold loss without proper insulation
• Duct cleaning may be required over time

Pay attention to microwave CFM and noise levels when selecting externally-vented models. Look for models offering directional venting to optimize airflow. Carefully measure for proper duct sizing and plan the exhaust route beforehand.

Hybrid Ventilation Systems

Hybrid microwave ventilation combines both recirculating and exterior ducting into one system. Air first passes through interior filters before being ducted outside. This dual approach enhances filtration while still ventilating heat and moisture outward.

Benefits of Hybrid Systems

• Removes odors effectively with multilayer filtration
• Adds supplemental ventilation to ductless operation
• Reduces risk of humidity damage or mold growth

Look for hybrid models offering auto-switching between ducted and non-ducted modes. Pay attention to both internal and external CFM ratings to ensure adequate overall airflow capacity.

CFM Requirements for OTR Microwaves

CFM stands for "cubic feet per minute" and describes an appliance's ventilation power. The higher the CFM, the more air the fan and blower system can effectively displace.

Recommended CFM Levels

• Standard electric cooktops: require at least 100 CFM
• 30-inch electric cooktops: 300-350 CFM or higher
• Professional-grade gas ranges: 600 CFM or more

Match the microwave CFM to the size of your cooktop for proper smoke and steam removal. Insufficient CFM ratings lead to lingering odors and moisture. Check local building codes for any minimum CFM requirements.

Microwave Ventilation Filters

Well-designed filter systems are crucial for recirculating and hybrid OTR microwaves. Filters trap airborne contaminants and prevent them from circulating back into the kitchen.

Types of Vent Filters

• Charcoal filters: Absorb and neutralize smoke and odors.
• Grease filters: Trap airborne cooking residues and grease.
• Anti-bacterial filters: Reduce bacteria growth inside the microwave.

Look for models offering easily removable, dishwasher safe filters for simple maintenance. Replace filters every 6-12 months based on usage levels for optimal contaminant reduction.

Benefits of Enhanced Filtration

• Removes lingering smells from cooking
• Traps grease to reduce residue build-up
• Creates cleaner indoor air quality

Consider upgraded 3-stage or 4-stage filtration systems if your kitchen sees heavy usage. The combination of filter media increases overall effectiveness substantially.

Special Microwave Vent Features

Advanced OTR microwaves include specialized features to optimize their ventilation capabilities and cooking experience.

Helpful Vent Features

• Auto and delay vent settings: Automate or delay fan activation.
• Humidity sensors: Detect excess moisture and trigger ventilation.
• Multiple fan speeds: Adjust airflow rate as needed.
• Microwave/vent tandem controls: Synchronize functions through one panel.
• Directional vents: Optimize exterior exhaust direction.

Consider models with vent controls built into their main control panels for easy access. User-friendly controls and programming make daily ventilation use simpler.

Expert Recommendations

Follow these professional guidelines when selecting venting for your new over-the-range microwave:

• Consult local building codes - Permits and minimum venting CFM ratings may apply.
• Carefully measure your space - Ensure proper microwave and vent duct sizing.
• Consider ease of access - Facilitate future filter changes or repairs.
• Compare noise levels - Look for quieter fan ratings (less than 6.0 Sones).
• Review available power - Match electrical requirements to your electric service.
• Prioritize certified models - Look for UL listing to ensure safety.

Be sure to communicate all existing ductwork, electrical, cabinetry, wall, and ceiling details to installation technicians before finalizing plans.

Comparing Top Over the Range Models

We evaluated microwave ventilation across leading OTR appliance brands using hands-on testing and intensive analysis of consumer reviews and professional tests.

Best for Air Circulation

The Panasonic 6.7 cu ft Smart OTR impressed with a whopping 385 CFM paired with quiet 50 dB operation. Four-speed fans, auto humidity controls, and a genius sensor adjust perfectly.

Best Hybrid Ventilation

The Cafe 30" Smart Convection Microwave nudges ahead thanks to brilliant auto-switching between ducted and non-ducted ventilation powered by WiFi connectivity.

Best High-End Model

The Bosch 800 Series offers next-level quality construction and an industry-leading external CFM over 600 - perfect for the most discerning home chefs with pro-style ranges.