Kitchen Ventilation Calculator
Determine Your Ventilation Needs
Based on Australian Building Code requirements and health guidelines, this calculator helps you find the right extractor fan for your kitchen.
Quick Takeaways
- Without proper ventilation, cooking fumes can lower indoor air quality and promote mould growth.
- Australian Building Code requires a minimum ventilation rate for balconies and enclosed kitchens.
- Three common fan styles - ducted, ceiling‑mounted and wall‑mounted - each have trade‑offs in airflow, noise and cost.
- Energy‑efficient fans can save up to 30% on electricity compared with older models.
- Regular cleaning of the fan and its ductwork prevents fire risk and keeps performance steady.
When you hear the hum of a extractor fan that pulls steam, smoke and cooking odors out of the kitchen and vents them outside, you might wonder if it’s really worth the expense. The short answer: yes, in most Australian homes it’s more than a convenience - it’s a health and safety feature.
Below we’ll walk through why you need one, what can happen if you skip it, how to pick the right style, and what the ongoing costs look like. By the end you’ll know if a fan is essential for your kitchen or if you can get by with other measures.
Why Kitchen Ventilation Matters
Cooking releases a cocktail of moisture, grease particles, nitrogen dioxide and carbon monoxide. In a tightly sealed home, especially in Perth’s hot climate where windows stay closed for cooling, those pollutants linger and affect indoor air quality the condition of the air inside a building, measured by levels of contaminants, humidity and temperature. Poor air quality can trigger asthma, eye irritation and chronic respiratory problems.
Moisture is a silent enemy. When steam hits cool surfaces it condenses, creating a damp environment perfect for mould fungi that grow on wet surfaces, releasing spores that aggravate allergies and cause structural damage. A study by the Australian Institute of Health and Welfare (2023) linked households without adequate kitchen ventilation to a 22% higher incidence of mould‑related health complaints.
What Happens If You Skip the Fan?
Many homeowners try to rely on windows or range hoods that simply recirculate air. That approach falls short for three reasons:
- Insufficient airflow: Windows rarely provide the 15-20 cubic meters per minute (CFM) needed to clear cooking fumes quickly.
- Grease buildup: Recirculating filters trap some particles but eventually clog, reducing efficiency and increasing fire risk.
- Regulatory non‑compliance: The Australian Building Code the national set of standards governing construction and safety in Australia mandates permanent mechanical ventilation for enclosed kitchens in most new builds.
If you ignore these points, you may notice lingering smells, sticky cabinets, or worse - signs of mold on walls and ceilings. Over time, the added humidity can warp timber, corrode metal fixtures, and even affect the performance of nearby appliances.
Types of Extractor Fans and How They Differ
Not all fans are created equal. Below is a quick rundown of the three most common designs in Australian homes.
| Fan Type | Typical Airflow (CFM) | Noise Level (dB) | Installation Cost (AUD) | Best For |
|---|---|---|---|---|
| Ducted fan | 150-300 | 45-55 | 300-600 | Large kitchens, high‑heat cooking |
| Ceiling‑mounted fan | 120-200 | 40-50 | 200-450 | Open‑plan layouts, limited wall space |
| Wall‑mounted fan | 100-180 | 38-48 | 150-350 | Compact kitchens, retrofit projects |
All three can be paired with a backdraft damper a valve that prevents outside air from flowing back into the duct when the fan is off, which protects against drafts and water ingress.
Energy Use and Cost Savings
Modern fans often carry an Energy Star rating. A 150 CFM fan with a 70 W motor will draw roughly 0.5 kWh per hour of use. If you run it for 30 minutes each night, the annual electricity cost is about AUD 40. Older, less efficient models can use twice that amount.
Beyond electricity, consider the long‑term savings from avoiding mould remediation (which can run into thousands of dollars) and from preserving the lifespan of cabinets and appliances that suffer from humidity damage.
Installation Tips - Do It Yourself or Call a Pro?
If you’re handy, installing a wall‑mounted or ceiling‑mounted fan can be a weekend project. Here’s a high‑level checklist:
- Confirm the fan meets the airflow requirement for your kitchen size (roughly 10 CFM per square metre of cooking area).
- Choose a location at least 600 mm above the cooking surface to capture rising steam.
- Cut an opening in the wall or ceiling that matches the fan’s diameter - use a jigsaw or hole‑saw for clean edges.
- Install the backdraft damper inside the duct before sealing it to the outside.
- Secure the fan housing, connect the wiring to a dedicated circuit, and test for proper airflow with a smoke pen or incense stick.
If any of those steps feel beyond your skill set, especially working with electricity or roof penetrations, hiring a licensed electrician or ventilation specialist is safest. In Perth, the average labor rate for a full install is AUD 120-150 per hour.
Maintenance - Keep It Running Smoothly
Even the best fan can lose performance if you neglect it. Follow this simple routine:
- Wipe the outer cover weekly with a damp cloth.
- Clean the metal filter every 2-4 weeks - soak it in hot soapy water, rinse, and let dry.
- Inspect the ductwork yearly for grease buildup; a professional cleaning service costs about AUD 120.
- Listen for unusual noises that could indicate a loose blade or motor wear.
Replacing a motor after 8-10 years is typical. Most manufacturers offer a 2‑year warranty on new units, so keep your receipt.
Frequently Asked Questions
Do I need a permit to install an extractor fan in Perth?
Most standard kitchen fans are considered low‑risk electrical work, so a permit isn’t required if you use an existing circuit. However, if you’re adding a new dedicated line or cutting through a fire‑rated wall, the local council may ask for a building permit.
Can I run a fan without ducting?
Recirculating range hoods exist, but they don’t remove humidity or carbon monoxide. For true air‑quality improvement you need a duct that vents to the outside.
What CFM rating is enough for a 12‑person household?
Aim for at least 150 CFM for a standard 3‑hour cooking session. If you often use a wok or grill, bump it up to 200‑250 CFM.
How often should I replace the fan filter?
Metal grease filters can be washed and reused for 2-3 years. Charcoal filters, used for odor removal, typically need replacement every 6‑12 months.
Will an extractor fan lower my energy bill?
Yes, by removing moisture you reduce the load on your air‑conditioner, which can shave 5‑10% off your cooling costs during summer.
In a nutshell, a properly sized and maintained extractor fan is a small investment that protects your health, your home’s structure, and even your electricity bill. If you’re still on the fence, weigh the cost of a fan and its installation against the potential expense of mould remediation, medical bills, and lost appliance life. Most homeowners find the fan pays for itself within a few years.