Extractor Fan Sizing Calculator
Room Requirements Calculator
Calculate the minimum airflow needed for proper ventilation in your bathroom, kitchen or laundry room.
Enter your room dimensions to calculate the minimum airflow requirement.
According to Australian Standards (AS/NZS 3000), proper ventilation is essential for:
- Bathroom: At least 8 air changes per hour
- Kitchen: At least 8 air changes per hour
- Laundry: At least 6 air changes per hour
When your extractor fan stops working, it’s not just annoying-it’s a health risk. Moisture builds up, mold grows, and odors linger. You might think, "I’ll just replace it myself." But here’s the truth: extractor fan installation isn’t just about screwing in a new unit. It’s about correct ventilation, electrical safety, building codes, and long-term performance. So who actually installs extractor fans? And why does it matter who does it?
Electricians Are the Go-To for Most Extractor Fan Installations
Most extractor fans need to be wired into your home’s electrical system. That means a licensed electrician is legally required in Australia to handle the job. Even if you buy a fan that looks simple-like a wall-mounted unit for your bathroom-connecting it to the power supply isn’t a DIY task. Incorrect wiring can cause short circuits, overheating, or even fire. In South Australia, the Electrical Safety Act 2002 makes it clear: only licensed professionals can install or modify fixed electrical wiring, including extractor fans.
Electricians don’t just connect wires. They check your circuit load, ensure the fan is on the right circuit breaker, and verify grounding. They also know how to install isolation switches and RCD protection, which are mandatory in wet areas like bathrooms. If your fan is part of a ventilation system with ducting running through the ceiling or roof, the electrician will coordinate with other trades to make sure everything aligns.
Handymen Can Help-But Only If They’re Qualified
You might see ads for "handymen" offering cheap extractor fan installation. Some are trustworthy, others aren’t. The problem? Many handymen aren’t licensed electricians. They might be able to mount the fan, drill holes, or attach ducting-but if they’re touching wires, they’re breaking the law. In Adelaide, a handyman without an electrical license can’t legally install a fan that plugs into a fixed circuit. If something goes wrong later, your insurance won’t cover damage caused by unlicensed work.
Some handymen work alongside electricians. They handle the physical mounting and ducting while the electrician handles the wiring. That’s fine-if you know who’s doing what. Always ask: "Are you licensed to install electrical appliances?" If they hesitate, walk away.
Plumbers and HVAC Technicians Also Install Extractor Fans
Not all extractor fans are just about electricity. If you’re installing a high-performance range hood above your cooktop, or a whole-house ventilation system, you might need an HVAC technician. These specialists understand airflow, duct sizing, static pressure, and exhaust vent placement. They know how to prevent backdrafting, which can pull carbon monoxide back into your home.
Plumbers occasionally install extractor fans too-especially in bathrooms where the fan connects to a plumbing vent stack or where moisture control ties into the drainage system. But again, if wiring is involved, they must either be dual-licensed or work with an electrician.
For simple bathroom fans, an electrician is enough. For complex kitchen hoods with multiple motors, lighting, and remote controls, an HVAC pro is the better choice. Don’t assume all installers are the same. Match the installer to the complexity of the job.
What About DIY Installation?
Yes, you can buy a fan at Bunnings or Amazon and install it yourself. But here’s what most people don’t realize: the real cost isn’t the $80 fan-it’s the hidden risks.
- Improper ducting can trap moisture inside walls, leading to rot and mold.
- Wrong fan size means it won’t remove enough air-your bathroom will stay steamy, your kitchen will smell like last night’s curry.
- Connecting to the wrong circuit can overload your breaker, or worse, cause a shock.
- If you’re renting, your landlord can hold you responsible for unlicensed modifications.
In 2023, SA Health reported over 400 cases of mold-related respiratory issues linked to poor bathroom ventilation. Many of those homes had fans installed by unqualified people. The fan ran, but it didn’t vent properly. That’s not a fix-it’s a time bomb.
What to Look for in a Professional Installer
Not all electricians are equal when it comes to extractor fans. Here’s what to ask before hiring anyone:
- "Are you licensed to install electrical appliances in South Australia?" (Ask for their license number and check it on the Consumer and Business Services website.)
- "Have you installed this exact type of fan before?" (Some fans need special mounting brackets or remote controls.)
- "Will you handle ducting and exhaust venting?" (The fan must vent to the outside-not into the roof space.)
- "Do you provide a certificate of compliance?" (This is legally required for all electrical work in Australia.)
- "Do you offer a warranty on your work?" (Good installers stand by their jobs for at least 12 months.)
A reputable installer will show you their license, explain the airflow requirements for your room size, and recommend the right fan based on cubic meters per second (m³/s). A bathroom under 10m² needs at least 15 m³/s. A kitchen needs 80-120 m³/s. If they don’t know these numbers, they’re guessing.
How Much Does It Cost to Install an Extractor Fan?
Prices vary based on location, complexity, and fan type. Here’s what you’ll typically pay in Adelaide as of 2025:
| Fan Type | Cost of Fan | Installation Cost | Total Estimate |
|---|---|---|---|
| Basic Bathroom Wall Fan | $60-$120 | $150-$250 | $210-$370 |
| Ceiling-Mounted Bathroom Fan | $80-$180 | $200-$300 | $280-$480 |
| Range Hood (Kitchen) | $250-$800 | $250-$500 | $500-$1,300 |
| Whole-House Ventilation System | $1,200-$3,000 | $800-$1,500 | $2,000-$4,500 |
Don’t be tempted by the cheapest quote. A $90 job might mean no ducting, no compliance certificate, and a fan that stops working in six months. Paying $250 for a proper install with a certificate saves you hundreds later on repairs or mold remediation.
What If Your Fan Needs Repair Instead?
Before you replace the fan, check if it just needs fixing. Common issues:
- Motor failure (often fixable for $80-$150)
- Dirty or clogged filters (cleaning costs $50)
- Loose or disconnected ducting (reconnecting is $100-$180)
- Faulty switch or timer (replacement: $120-$200)
Many extractor fans last 10-15 years. If yours is less than 5 years old and just making noise, it’s probably not dead-just dirty or misaligned. A qualified technician can clean it, realign the blades, and test airflow. That’s cheaper than replacing it.
When to Call a Professional (And When Not To)
Call a pro if:
- You’re replacing a fan that was wired into the wall
- You’re installing in a bathroom, laundry, or kitchen
- You need new ducting or roof penetration
- You’re unsure about electrical safety
You might handle it yourself if:
- You’re replacing a plug-in fan (like a window-mounted unit)
- You’re only replacing the motor in a fan you already own
- You have a certified electrical background
But even then-ask yourself: is saving $200 worth risking your home’s safety?
Final Advice: Don’t Risk It
Extractor fans are one of those home features you never think about-until you’re wiping mold off your bathroom tiles or coughing from kitchen smoke. The right installer doesn’t just mount a fan. They ensure your home is safe, dry, and healthy.
Don’t hire the first person who shows up with a van. Get three quotes. Ask for proof of license. Ask for a compliance certificate. Make sure they vent to the outside-not the roof. And if you’re renting, get your landlord’s permission before any work starts.
It’s not about spending more. It’s about spending wisely.
Can I install an extractor fan myself in Australia?
You can physically mount a fan yourself, but if it requires wiring into your home’s electrical system, it’s illegal to do so without a licensed electrician in Australia. Even if you’re skilled, the law requires certification for fixed electrical installations. Doing it yourself can void your home insurance and lead to fines.
Do I need a permit to install an extractor fan?
In most cases, no formal permit is needed for a standard bathroom or kitchen extractor fan. But the installation must still comply with Australian Standards (AS/NZS 3000) and be certified by a licensed electrician. The certificate of compliance serves as your legal proof that the work meets safety codes.
What’s the difference between a bathroom fan and a range hood?
Bathroom fans are designed to remove moisture and odors and usually have lower airflow (15-30 m³/s). Range hoods are built to handle grease, smoke, and high heat, with airflow between 80-120 m³/s. They also have filters and stronger motors. Never use a bathroom fan over a cooktop-it won’t capture grease and can become a fire hazard.
Can an extractor fan be vented into the roof space?
No. Venting into the roof space is against building codes in Australia. Moisture trapped in the roof cavity causes timber rot, insulation damage, and mold growth. All extractor fans must vent directly to the outside-through a wall, roof, or eave. A qualified installer will ensure the exhaust outlet is properly sealed and positioned away from windows or air intakes.
How do I know if my extractor fan is powerful enough?
Calculate your room’s volume in cubic meters (length × width × height). For bathrooms, multiply that by 8 to get the minimum airflow needed in m³/h. Then divide by 3,600 to convert to m³/s. For example, a 3m × 2m × 2.4m bathroom = 14.4m³. 14.4 × 8 = 115.2 m³/h. 115.2 ÷ 3,600 = 0.032 m³/s. You need at least 0.03 m³/s. Most standard fans offer 0.05-0.08 m³/s-plenty for small rooms.
