Expert Ventilation
Expert Ventilation Methods
A Complete Guide to Fresh Air Circulation & Mechanical Systems for Homes, Offices, and Commercial Spaces from Daikin Experts.
Choose Your Home Type
Proper air exchange in homes and apartments is essential for your family's health. Daikin shares practical, science-based guidance on how to ventilate your rooms.
1. What Is Ventilation and Why Is It Important?
Ventilation is the process of replacing stale indoor air with fresh outdoor air.
Why does it matter?
In enclosed rooms, various pollutants such as harmful substances (CO2, CO, formaldehyde), dust, mold, viruses, and odors build up from everyday human activities and household items.
Does an AC cool and ventilate at the same time?
Many people assume an AC ventilates while it cools a room. In fact, most standard ACs only draw in indoor air, cool or heat it, and blow it back out. Standard ACs do NOT exchange indoor air with outdoor air.
Standard Ventilation Duration & Frequency:
Ventilate for 5 to 10 minutes once every hour. Ventilating twice for 5 minutes per hour is far more effective than once for 10 minutes every 2 hours.
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Difference Diagram: Regular AC (Cools Indoor Air Only) vs Ventilation System (Exchanges Fresh Outdoor Air)
2. How to Ventilate a House
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Airflow Diagram: 2 Diagonal Windows (Correct) vs. 2 Adjacent Windows (Incorrect)
2.1. Open Two Windows Opposite Each Other (Diagonally)
The most basic and effective way to ventilate is to open two windows. Open two windows positioned diagonally (opposite each other) in the room. This creates an inlet and an outlet for air, allowing the breeze to flow smoothly.
If two adjacent windows are opened, air only swirls within a small area and does not circulate throughout the room.
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Diagram of a Fan Pointed Out the Window to Push Air Outside
2.2. If There Is Only One Window- Use a Fan (Circulator)
If the room has only 1 window, open it and point a fan OUT through the window.
The fan pushes stale indoor air out through the window and naturally draws fresh air in through door gaps or from other rooms.
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Airflow Diagram of a Windowless Room Toward the Main Room & Exhaust Fan
2.3. Ventilating Windowless Rooms
For rooms without windows (such as an interior bedroom or inner workspace):
- Open the room door.
- Turn on a fan inside the room, pointing out through the door.
- Open a window in the nearest room (such as the living room) and turn on the bathroom or kitchen exhaust fan.
3. How to Ventilate Apartments & CondominIUMs
3.1 Airtight Characteristics of Apartments
Modern apartments have a high level of airtightness. This makes natural air circulation more difficult than in landed houses unless mechanical ventilation is used.
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Apartment Airflow Diagram from the Balcony Through Door Gaps to a 24-Hour Exhaust Fan
3.2. Use Bathroom & Kitchen Exhaust Fans (24-Hour Ventilation)
In apartments, exhaust fans in bathrooms, toilets, and kitchens play the most important role. Keep the bathroom exhaust fan running continuously (24 hours).
The exhaust fan continuously draws air out, creating gentle negative pressure that pulls fresh air in through door gaps or balcony vents.
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Diagram of Ventilating with a Window Open 10 cm While the AC Stays On
3.3. Ventilation While the AC Is On (Hot / Rainy Season)
Should you turn off the AC while ventilating?
There's no need to turn off the AC! Repeatedly switching the AC off and on actually uses more electricity. Keep the AC running while you open the windows for 5-10 minutes to ventilate.
Open the window slightly (about 10 cm) so the air exchange happens gradually without making the AC's workload spike too high.
Residential Ventilation Documentation Placement
Click a thumbnail image to open a pop-up with detailed instructions & placement illustrations.
Summary of the 4 Key Rules of Residential Ventilation
5-10 Minute Duration
Ventilate for 5-10 minutes once every hour.
2 Diagonal Windows
Open 2 opposite windows for smooth airflow.
Fan Facing Outward
Point a fan toward the window if there is only 1 window.
24-Hour Exhaust
Keep the bathroom exhaust fan running continuously in apartments.
Want to Apply a Daikin VAM (HRV) Ventilation System in Your Building or Store?
Consult on your commercial air purification & mechanical ventilation system needs with our Daikin engineering team.