Keeping your home warm, energy-efficient, and safe is a top priority—especially during those long, chilly Australian winters. One often overlooked but essential part of your heating setup is the flue system. That’s where the Room Sealed Flue (RSF) kit comes in.
This article is your complete guide to Room Sealed Flue kits—what they are, how they work, why they’re essential, and how to install them the right way in compliance with Australian standards.
What is an RSF (Room Sealed Flue) Kit?
A Room Sealed Flue Kit RSF is a closed combustion flue system used for gas appliances like heaters and fireplaces. Unlike traditional open flue systems, RSFs draw air from outside the building for combustion and vent exhaust gases back outside—keeping indoor air completely separate.
Why It Matters in Modern Australian Homes
Modern homes are becoming tighter and more energy-efficient, which means they don’t “breathe” like older homes. In such airtight environments, room-sealed flue systems help prevent back-drafting and ensure safe, clean combustion without affecting indoor air quality.
How Room Sealed Flue Systems Work
Closed Combustion Explained
In a closed combustion system, your gas appliance takes in air from outside via a concentric flue pipe, not from your living space. This is the key difference between RSF and open flue systems.
Fresh Air Intake and Exhaust in One Pipe
The RSF system typically uses a concentric flue pipe—a pipe within a pipe. The outer pipe draws in fresh air for combustion, while the inner pipe vents out exhaust gases.
Benefits of Using RSF Flue Kits
Improved Indoor Air Quality
Because RSFs don’t use room air for combustion, there’s no risk of combustion gases leaking into your living space. That means healthier, cleaner air indoors—especially important for families and people with respiratory issues.
Higher Heating Efficiency
Closed systems retain more heat by improving combustion efficiency and reducing drafts. Less cold air enters your home, and more warmth stays inside.
Enhanced Safety
Room-sealed kits prevent:
- Carbon monoxide leakage
- Backdrafting
- Negative air pressure issues
It’s the safest option for modern, energy-efficient homes.
Components of a Room Sealed Flue Kit
A typical RSF kit includes:
- Concentric flue pipes (often stainless steel)
- Sealing collars
- Wall terminal or ceiling terminal (for venting)
- Mounting brackets
- Condensation trap (optional in some systems)
All parts work together to ensure air is drawn from and expelled to the outside.
RSF vs Traditional Open Flue Systems
| Feature | Room Sealed Flue | Open Flue |
|---|---|---|
| Air Source | Outside | Inside room |
| Safety | High | Moderate |
| Indoor Air Quality | Maintained | Can be compromised |
| Suitable for Airtight Homes | Yes | No |
| Efficiency | High | Medium |
Ideal Applications for RSF Flue Kits
Gas Fireplaces and Heaters
Most modern gas fireplaces and wall-mounted gas heaters are designed to work best with RSF systems. Brands like Escea, Rinnai, and Real Flame often recommend or require them.
Tight or Passive Homes
RSF kits are practically essential in:
- Passive design homes
- Energy-efficient new builds
- Homes with double glazing and insulation
Apartments and Townhouses
Because RSF vents can run horizontally or vertically, they’re ideal for compact dwellings where vertical venting may not be possible.
Australian Standards and Compliance
AS/NZS 5601 Gas Installations
Your RSF setup must comply with AS/NZS 5601, the official standard governing gas installation safety in Australia.
Key requirements:
- Proper clearance from combustible materials
- Correct termination points
- Approved materials and connections
Use With Certified Appliances
Always check your heater or fireplace manual for RSF compatibility. Not all gas appliances are designed for sealed flue use.
Installation Best Practices
Horizontal vs Vertical Installation
- Horizontal Flue Kits: Common in apartments or wall-mounted heaters. Exit through an external wall.
- Vertical Flue Kits: Suitable for fireplace-style heaters. Vent through the roof.
Termination Rules
- Must terminate at least 500mm from any opening (door/window)
- Minimum height above ground or roofline must be followed
- Must prevent rainwater or animals entering
Tips from Certified Installers
- Use only approved RSF kits—not DIY mixes
- Always maintain pipe gradient to allow for condensation drainage
- Avoid long bends that could disrupt air intake or exhaust
Common Problems and Troubleshooting
Blocked Flue
Can occur from:
- Bird nests
- Insects
- Leaves or debris
Solution: Regular inspection and bird guards.
Condensation in Flue
If you hear dripping, it’s likely condensation forming inside the pipe.
Solution: Use insulated flue sections or condensation traps.
Backdraft or Incomplete Combustion
Often due to improper installation or incompatible appliance.
Solution: Hire a licensed technician for inspection.
RSF for Energy-Efficient Heating
RSF kits are perfect for use with 5-star or 6-star rated gas appliances. They allow those units to reach their full efficiency potential by preserving thermal balance and preventing heat loss through room air draw.
Popular RSF Brands in Australia
Stainless Flue AU
Trusted supplier of stainless steel flue systems, including concentric and twin-wall RSF kits.
Escea Fireplaces
Modern gas fireplaces designed with room-sealed flue systems as standard.
Rinnai and Real Flame
Offer wall-mounted heaters with optional or included RSF compatibility.
Cost and Lifespan of RSF Kits
How Much Do They Cost?
Average price range:
- Horizontal RSF kit: $300–$600
- Vertical RSF kit: $500–$900
- Custom or longer kits may exceed $1000
Lifespan and Warranty
- Stainless steel RSF kits: 15–20 years
- Galvanised steel: 10–15 years
- Most come with 5–10 year warranties
Why RSF is the Future of Safe Heating
In a world shifting toward energy-efficient, sustainable housing, RSF systems are a no-brainer. They:
- Minimise air leakage
- Protect indoor air quality
- Reduce CO poisoning risks
- Support green building certifications (e.g., NatHERS, Green Star)
They’re not just the future—they’re the present standard.
Testimonials from Australian Homeowners
“We installed a Rinnai gas heater with an RSF kit from Stainless Flue AU. No smell, no drafts—just warmth!”
– Lisa from Melbourne
“Our new build had tight insulation, and RSF was the only safe choice. Works perfectly and looks sleek too.”
– Dave from Adelaide
“The old open flue gave us problems every winter. Switched to RSF and never looked back.”
– Nisha from Sydney
Conclusion
If you’re installing or upgrading a gas heater or fireplace in Australia, a Room Sealed Flue Kit is more than just a smart choice—it’s a safety essential. With rising standards in energy efficiency and airtight design, RSF kits are the ideal solution to protect your air quality, reduce energy bills, and keep your home warm all winter long.
