For many homeowners living in high-rise condos, historic buildings, or modern open-concept apartments, installing a traditional ducted range hood is simply impossible. You cannot drill a hole through the ceiling or the neighbor's wall.
Enter the Ductless Range Hood (also known as a recirculating hood). It is the unsung hero of flexible kitchen design. But how exactly does it clean the air if it doesn't vent it outside? Is it magic, or is it science?
In this comprehensive guide, we will break down the mechanics of recirculation, explain the two-stage filtration process, and provide a step-by-step masterclass on how to maintain your filters for peak performance.
Unlike ducted hoods, ductless models scrub the air and return it to the room.
Phase 1: The Anatomy of Airflow (How It Works)
Think of a ducted hood as a vacuum cleaner that empties the trash outside. Think of a ductless range hood as a high-performance air purifier.
The process happens in four distinct stages:
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1. The Suction:
The powerful motor creates negative pressure, pulling smoke, steam, and grease-laden air upwards from your cooktop. -
2. The Grease Trap (Stage 1 Filtration):
The air first hits the metal Mesh or Baffle filters. These are designed to catch heavy oil particles and grease droplets before they reach the motor. -
3. The Odor Scrubber (Stage 2 Filtration):
This is the ductless difference. The air is forced through Activated Carbon (Charcoal) Filters. The porous carbon traps microscopic odor molecules, smoke particles, and volatile organic compounds (VOCs). -
4. The Recirculation:
Now cleaned of grease and odors, the fresh air is pushed out through vents at the top of the chimney or the front of the cabinet, returning to your kitchen.
No Vent? No Problem.
Explore our collection specifically engineered for recirculation efficiency.
Shop Ductless Range Hoods →Phase 2: Understanding the Carbon Filter
The success of a ductless hood relies entirely on the quality of its carbon filters. Carbon is "activated" by processing it to have low-volume pores that increase the surface area available for adsorption.
Did you know? Just one gram of activated carbon has a surface area in excess of 500 m² (about one-tenth the size of a football field). This massive surface area is what grabs onto the smell of burnt garlic or fried fish and holds it tight.
Phase 3: The Maintenance Masterclass (Step-by-Step)
The #1 complaint about ductless hoods is "it stopped working." 99% of the time, this is because the owner didn't maintain the filters. Here is exactly how to do it.
Part A: The Metal Grease Filters (Washable)
These are the outer filters (Stainless Steel Baffle or Aluminum Mesh). Frequency: Every 3-4 Weeks.
- Remove: Locate the latch on the filter panel and pop them out.
- Prepare the Solution: Plug your sink. Fill it with boiling water. Add 1/4 cup of Baking Soda and a generous squirt of Degreasing Dish Soap (like Dawn). Mix until bubbly.
- Soak: Submerge the filters completely. Let them sit for 15-30 minutes. You will see the grease separating and floating to the top.
- Scrub: For stubborn spots, use a soft-bristle brush (like an old toothbrush). Do not use steel wool on stainless steel baffles as it scratches.
- Rinse & Dry: Rinse thoroughly with warm water. Wipe dry with a microfiber cloth before reinstalling.
Part B: The Carbon Filters (Disposable)
These are the black discs attached to the motor. Frequency: Every 3-6 Months.
⚠️ CRITICAL WARNING:
You CANNOT wash, soak, or clean charcoal filters. Once the carbon pores are full of grease and odor, they are done. Getting them wet ruins them completely. You must replace them.
- Access: Remove the metal grease filters first.
- Remove Old Filters: Locate the round black filters on the side of the motor. Twist them counter-clockwise (usually) to unlock and pull them off.
- Install New Filters: Align the locking tabs of the new filter. Push gently and twist clockwise until it clicks securely into place.
- Test: Turn on the hood to ensure there is no rattling sound.
Phase 4: Pros and Cons of Going Ductless
✅ The Pros
- Versatility: Install anywhere (Kitchen islands, interior walls).
- Cost: No expensive ductwork installation or contractor fees.
- Heat Retention: Doesn't pump your home's heated/cooled air outside (energy efficient in winter).
❌ The Cons
- Humidity: Cannot remove steam or heat from the kitchen, only particles.
- Maintenance: Ongoing cost of replacing charcoal filters.
- Noise: Can be slightly louder due to air resistance through filters.
The Brano Verdict
A ductless range hood is a fantastic solution for modern living. While it requires a bit more maintenance than a ducted system, it provides essential filtration for your health and keeps your cabinets grease-free.
If you are unsure which filter fits your Brano model, please check our User Manuals or contact our support team.
Frequently Asked Questions (Ductless FAQ)
1. Do ductless range hoods actually work?
Yes. While they don't vent air outside, they are highly effective at trapping grease and neutralizing cooking odors using activated carbon technology, significantly improving indoor air quality.
2. Where does the air go in a ductless hood?
After passing through the filters, the clean air is recirculated back into the kitchen through vents located at the top of the chimney stack or the front of the unit.
3. Can ductless hoods remove heat and steam?
No. This is the main limitation. Since air is recirculated, heat and moisture remain in the room. You may need to open a window while boiling water for long periods.
4. Can I wash the charcoal filters?
Absolutely not. Washing charcoal filters destroys their structure and effectiveness. They must be discarded and replaced with new ones.
5. How often should I replace the carbon filters?
For average daily cooking, replace them every 3 to 6 months. If you fry food frequently or cook with strong spices, replace them every 2 months.
6. Are ductless hoods easy to install?
Yes, they are generally easier to install than ducted hoods because you do not need to cut holes in walls or ceilings for ductwork. You just need to mount it and plug it in.
7. Do I need a special kit to make my hood ductless?
Most "Convertible" range hoods require a separate Ductless Kit (which includes the charcoal filters) that is sold separately. Check your product description.
8. Are ductless hoods safe for gas stoves?
Yes, but with caveats. Gas stoves produce heat and carbon monoxide. While a ductless hood removes grease, it does not remove CO. Ensure your kitchen has adequate airflow/ventilation elsewhere.
9. Why is my ductless hood so loud?
Ductless hoods can be slightly louder because the motor has to work harder to push air through the dense charcoal filters compared to an open duct.
10. Can I convert a ductless hood to ducted later?
If you bought a "Convertible" model, yes! You simply remove the charcoal filters and connect the hood to ductwork leading outside.