Microwave ovens are ubiquitous in modern kitchens, offering unparalleled convenience for quick meals and reheating leftovers. However, what many people don’t fully understand is the importance of proper ventilation, and the differences between various venting options. This article delves into the specifics of externally vented microwave ovens, exploring their functionality, benefits, installation, and how they compare to other venting styles.
Understanding Microwave Oven Ventilation
Ventilation in a microwave oven serves a crucial purpose: to remove smoke, steam, odors, and grease particles released during cooking. Without proper ventilation, these byproducts can accumulate, leading to unpleasant smells, greasy surfaces, and potential damage to your kitchen cabinets and appliances. Microwave ovens are typically categorized based on how they handle this venting process.
There are two primary types of microwave oven ventilation systems: recirculating (or ductless) and externally vented (or ducted) systems. Each has its own advantages and disadvantages, making it essential to understand the differences to choose the best option for your needs.
Exploring Externally Vented Microwaves
An externally vented microwave oven, also known as a ducted microwave, is designed to expel the smoke, steam, and odors produced during cooking outside of your home. This is achieved by connecting the microwave to an existing or newly installed ductwork system that leads to the exterior. This ductwork typically terminates at an outside wall or the roof.
This type of venting system is generally considered superior to recirculating systems because it completely removes the contaminants from the kitchen rather than simply filtering and recirculating them. The effectiveness of an externally vented microwave is significantly influenced by the quality of the ductwork and the power of the fan.
How External Venting Works
The fundamental principle behind an externally vented microwave is simple. A powerful fan within the microwave draws in air from above and around the cooktop. This air, laden with cooking byproducts, is then forced through a grease filter to capture larger particles. After passing through the filter, the air is channeled into the ductwork and exhausted outside the building.
The fan speed, measured in cubic feet per minute (CFM), is a crucial factor in determining the effectiveness of the venting system. A higher CFM rating indicates that the fan can move more air, resulting in better removal of smoke and odors. Most externally vented microwaves offer multiple fan speed settings, allowing you to adjust the ventilation based on the type of cooking you’re doing.
Advantages of External Venting
Externally vented microwaves offer several compelling advantages over recirculating models:
- Superior Air Quality: The most significant benefit is the complete removal of smoke, steam, odors, and grease from the kitchen, resulting in cleaner and fresher air. This is especially important for individuals with allergies or respiratory sensitivities.
- Reduced Grease Buildup: By expelling grease-laden air outside, external venting minimizes grease accumulation on kitchen surfaces, walls, and cabinets. This translates to less cleaning and maintenance over the long term.
- Improved Appliance Longevity: Excessive heat and grease can damage kitchen appliances. External venting helps to prevent this damage by removing these harmful elements from the cooking environment, potentially extending the lifespan of your other appliances.
- Enhanced Cooking Experience: Removing cooking odors can create a more pleasant and enjoyable cooking experience, allowing you to focus on creating delicious meals without being overwhelmed by lingering smells.
Disadvantages of External Venting
Despite the numerous benefits, externally vented microwaves also have some potential drawbacks:
- Installation Complexity: Installing an externally vented microwave can be more complex and expensive than installing a recirculating model. It requires connecting the microwave to existing ductwork or installing new ductwork, which may involve cutting through walls and ceilings. This often requires professional installation.
- Higher Upfront Cost: Externally vented microwaves tend to be more expensive than recirculating models due to the more powerful fan and the need for ductwork. The total cost, including installation, can be a significant investment.
- Potential for Energy Loss: If the ductwork is not properly insulated, it can lead to energy loss, especially during colder months. Warm air escaping through the ductwork can increase heating bills. Backdraft dampers are essential to prevent outside air from entering the kitchen.
- Space Requirements: Ductwork can take up valuable space, especially in smaller kitchens. The placement of the microwave and the routing of the ductwork need to be carefully planned to minimize space intrusion.
Choosing the Right Externally Vented Microwave
Selecting the right externally vented microwave involves considering several factors to ensure it meets your specific needs and kitchen setup.
CFM (Cubic Feet per Minute)
As mentioned earlier, CFM is a critical measure of the fan’s airflow capacity. The higher the CFM, the more effectively the microwave will remove smoke and odors. A general guideline is to choose a microwave with at least 300 CFM for average cooking needs. If you frequently cook foods that produce a lot of smoke or odors, such as stir-fries or fried foods, consider a microwave with a higher CFM rating (400 CFM or more).
Duct Size and Configuration
The size and configuration of the ductwork are crucial for optimal performance. The manufacturer’s specifications will typically recommend a specific duct size (e.g., 6-inch round or 3.25 x 10-inch rectangular). Using a smaller duct size can restrict airflow and reduce the effectiveness of the venting system. The ductwork should also be as straight and short as possible, with minimal bends and turns, to minimize resistance to airflow.
Microwave Size and Features
Consider the size of the microwave cavity and the features that are important to you. Microwave ovens come in various sizes, from compact models suitable for small kitchens to larger models that can accommodate larger dishes. Features such as sensor cooking, preset programs, and turntable options can enhance your cooking experience.
Noise Level
Microwave ovens can be noisy, especially when the fan is running at high speed. Check the decibel (dB) rating of the microwave to get an idea of its noise level. Lower dB ratings indicate quieter operation. Look for models that offer multiple fan speed settings, allowing you to reduce the noise level when full power isn’t needed.
Installation Requirements
Before purchasing an externally vented microwave, carefully assess the installation requirements. Consider whether you have existing ductwork that can be used or if you will need to install new ductwork. Factor in the cost of professional installation, if necessary. Ensure that the microwave you choose is compatible with your kitchen layout and that there is sufficient space for the microwave and the ductwork.
Installation Considerations
The installation of an externally vented microwave can range from relatively straightforward to quite complex, depending on whether existing ductwork is present and the complexity of the ductwork routing.
Existing Ductwork
If you already have ductwork in place from a previous range hood or microwave, the installation process will be simpler. You will need to ensure that the ductwork is the correct size and configuration for the new microwave. You may also need to modify the ductwork slightly to align with the microwave’s vent outlet.
New Ductwork Installation
Installing new ductwork involves running ductwork from the microwave’s vent outlet to an exterior wall or the roof. This may require cutting holes in walls and ceilings, which can be a challenging and messy task. It is essential to properly seal and insulate the ductwork to prevent air leaks and energy loss. Professional installation is often recommended for new ductwork installations.
DIY vs. Professional Installation
Whether you choose to install the microwave yourself or hire a professional depends on your skills and experience. If you are comfortable with basic carpentry and electrical work, and you have experience working with ductwork, you may be able to handle the installation yourself. However, if you are not confident in your abilities, it is best to hire a qualified contractor to ensure that the installation is done correctly and safely. Incorrect installation can lead to reduced venting performance, air leaks, and potential safety hazards.
Externally Vented vs. Recirculating Microwaves: A Comparison
Understanding the key differences between externally vented and recirculating microwaves is essential for making an informed decision.
| Feature | Externally Vented Microwave | Recirculating Microwave |
|---|---|---|
| Venting Method | Expels air outside the home through ductwork. | Filters air and recirculates it back into the kitchen. |
| Air Quality | Superior air quality due to complete removal of contaminants. | Less effective air quality as contaminants are only filtered, not removed. |
| Grease Buildup | Minimizes grease buildup on surfaces and cabinets. | Can lead to grease buildup over time. |
| Installation | More complex installation, often requires professional assistance. | Simpler installation, typically can be done by the homeowner. |
| Cost | Higher upfront cost due to more powerful fan and potential ductwork installation. | Lower upfront cost. |
| Energy Efficiency | Can be less energy efficient if ductwork is not properly insulated. | Generally more energy efficient. |
In summary, externally vented microwaves offer superior air quality and reduced grease buildup, but they come with higher installation costs and complexity. Recirculating microwaves are more affordable and easier to install, but they are less effective at removing smoke, steam, and odors.
Maintenance Tips for Externally Vented Microwaves
Proper maintenance is essential for ensuring the continued performance and longevity of your externally vented microwave.
- Clean the Grease Filter Regularly: The grease filter is the primary line of defense against grease buildup. Clean the filter at least once a month, or more frequently if you cook often. Most grease filters can be washed in the dishwasher.
- Inspect the Ductwork: Periodically inspect the ductwork for any signs of damage or leaks. Seal any leaks with duct tape or sealant.
- Clean the Microwave Interior: Regularly clean the interior of the microwave to remove food splatters and spills. This will help to prevent odors and maintain hygiene.
- Check the Exterior Vent: Ensure that the exterior vent is free of obstructions, such as leaves or debris.
- Replace the Charcoal Filter (if applicable): Some externally vented microwaves also include a charcoal filter to further remove odors. Replace the charcoal filter according to the manufacturer’s recommendations.
By following these maintenance tips, you can keep your externally vented microwave in good working condition for years to come.
Conclusion
An externally vented microwave oven represents a significant upgrade in kitchen ventilation technology. While requiring a greater initial investment and more complex installation compared to recirculating models, the benefits of superior air quality, reduced grease buildup, and improved appliance longevity make it a worthwhile consideration for many homeowners. Careful consideration of CFM, ductwork requirements, microwave features, and installation options will ensure you choose the right model to meet your specific needs and enjoy a cleaner, fresher, and more enjoyable cooking environment. Remember that proper maintenance is key to maximizing the performance and lifespan of your externally vented microwave.
What is the primary difference between an externally vented microwave and a recirculating microwave?
The key difference lies in how they handle the smoke, steam, and odors produced during cooking. An externally vented microwave, as the name suggests, exhausts these byproducts outside of your home through ductwork. This helps to maintain cleaner air and reduce grease buildup on kitchen surfaces.
Recirculating microwaves, on the other hand, use a filter (usually charcoal) to trap some of the grease and odors. The filtered air is then recirculated back into the kitchen. While convenient, this method is less effective at removing all contaminants and requires regular filter replacements to maintain performance.
Why might I choose an externally vented microwave over a recirculating one?
Choosing an externally vented microwave is primarily driven by concerns about indoor air quality and cleanliness. If you frequently cook meals that generate a lot of smoke or strong odors, an external vent will prevent these from lingering in your home. It also helps reduce the accumulation of grease on cabinets and walls, leading to easier cleaning and a healthier environment.
Furthermore, externally vented models offer a more powerful ventilation system compared to recirculating microwaves. This added ventilation capacity can significantly improve air circulation in your kitchen, especially if you lack a strong range hood. While installation might be more complex, the long-term benefits often outweigh the initial effort for many homeowners.
What are the installation requirements for an externally vented microwave?
The most crucial requirement is access to external ductwork that leads to the outside of your home. This typically involves connecting the microwave’s exhaust vent to an existing duct or installing new ductwork through a wall or roof. Professional installation is highly recommended, especially if you lack experience with ductwork and electrical wiring.
Another important factor is the microwave’s placement in relation to the ductwork. The shorter and straighter the duct run, the more efficient the ventilation system will be. Consider the proximity of exterior walls or the roof when deciding on the microwave’s location to minimize duct length and ensure optimal performance.
Can I convert a recirculating microwave to an externally vented one?
The feasibility of converting a recirculating microwave to an externally vented model depends on the microwave’s design and your kitchen’s existing infrastructure. Some microwaves are designed with a convertible option, allowing you to switch between recirculating and external venting with a few modifications and the addition of ductwork.
However, many recirculating microwaves are not designed for external venting. Attempting to force a conversion could damage the microwave or result in ineffective ventilation. Before attempting any modifications, consult the microwave’s user manual and consider seeking professional advice from an appliance technician or HVAC specialist.
What duct size is typically recommended for an externally vented microwave?
The recommended duct size is crucial for efficient ventilation. Typically, a 6-inch round duct is recommended for most externally vented microwaves. This diameter allows for adequate airflow and minimizes backpressure, ensuring effective removal of smoke and odors.
Using a smaller duct size can restrict airflow and reduce the ventilation system’s performance. It can also put strain on the microwave’s fan motor, potentially leading to premature failure. Always consult the microwave’s installation manual for the manufacturer’s specific duct size recommendations.
What are some potential drawbacks of an externally vented microwave?
The main drawback is the more complex and potentially costly installation process. Installing ductwork can be labor-intensive and require professional assistance, especially if you need to create new openings in your walls or roof. This adds to the overall expense compared to simply installing a recirculating microwave.
Another potential downside is the impact on your home’s energy efficiency if the ductwork is not properly sealed and insulated. Air leaks in the ductwork can allow warm air to escape during the winter and cool air to escape during the summer, increasing your energy bills. Regular maintenance and inspection of the ductwork are essential to prevent energy loss.
How do I maintain an externally vented microwave to ensure optimal performance?
Regular cleaning is essential for maintaining optimal performance. Clean the grease filter (if your model has one) frequently, ideally every month, to prevent clogs that can restrict airflow. Also, wipe down the interior of the microwave regularly to remove any food splatters that could contribute to odors.
Periodically inspect the ductwork for any signs of damage or blockage. Look for cracks, leaks, or debris that could impede airflow. Consider having the ductwork professionally cleaned every few years to remove accumulated grease and dust, ensuring efficient ventilation and preventing potential fire hazards.