Bushfire smoke playbook
HRV/ERV + ducted AC
Evaporative unit warning
On bushfire-smoke days in Sydney, what’s the safest way to run ducted AC if I also have HRV/ERV or evaporative units?
If you only read one line: on bushfire-smoke days in Sydney, keep outdoor smoke out by closing windows/doors,
run your ducted air conditioning on recirculate, and turn off (or “smoke-mode” limit) any system that pulls outdoor air in—especially evaporative cooling.
Then create one “clean-air room” and stay mostly in it.
1) Introduction & First Impressions
The tricky part about “smoke days” isn’t your ducted air conditioner. It’s the extra stuff attached to your home:
an HRV/ERV (fresh air ventilation) or an evaporative unit (which is basically a giant outdoor-air pump).
If you run the wrong mode, you can accidentally drag smoky air inside.
can be a great “smoke day shelter”… if it’s set up to recirculate indoor air and your ventilation is handled carefully.
Product context: what are we “reviewing” here?
Today’s “product” is really a safe operating method for ducted AC Sydney homes—especially whole house air conditioning Sydney setups—when outdoor air is dirty.
Think of it as a simple, repeatable routine you can use every time the air turns hazy.
Your credentials (EEAT)
This guide is written from the perspective of KYC Air Conditioning Sydney. Our team has 10+ years industry experience
and has serviced and installed 2000+ Sydney homes—including ducted heating and cooling Sydney systems across the Inner West,
Eastern Suburbs, Western Sydney, Northern Beaches and the North Shore.
(You can also see our Daikin ducted air conditioning Sydney specialist resource for background.)
Testing period: how long we’ve “tested” this
We’ve seen smoke-season call-outs for years: “ducted air conditioning not cooling properly”, “it smells smoky inside”, “filters are black”,
and “my HRV is making it worse.” So this guide is built from real jobs, plus 2026 public health advice.
2) Product Overview & Specifications
What’s “in the box” (your typical home setup)
- Ducted air conditioner (indoor unit + outdoor condenser, ducts to multiple rooms).
- Return air grille (where air comes back to be cooled/heated again).
- Controller (wired wall controller and/or app; sometimes with WiFi control).
- Optional fresh air intake (some ducted systems have this—important on smoke days).
- HRV/ERV (ventilation system that brings outside air in and pushes stale air out, with heat/moisture exchange).
- Evaporative unit (cooling that needs outdoor air + open windows to work properly).
Key specifications that matter (for smoke safety)
| Spec / feature | Why it matters on smoke days |
|---|---|
| Recirculate / reuse air mode | Stops (or reduces) outdoor air intake so you’re not importing smoke. |
| Filter type + condition | Smoke particles load filters fast. A clogged filter reduces airflow and can make the system noisy or underperform. |
| Zoning (ducted AC zoning systems) | Lets you “camp” in a smaller area (clean-air room) so you use less energy and get faster comfort. |
| Fresh air function (if fitted) | Great on normal days, risky on smoke days—needs to be turned off or tightly managed. |
| HRV/ERV outdoor intake | Usually brings outside air in. During heavy smoke, you may need to pause it or run it in a reduced/intake-limited mode. |
Price point (reality check, Sydney-specific)
People ask us things like “how much does ducted air conditioning cost in Sydney?”, “ducted AC installation cost Sydney”, or
“ducted air conditioning sydney prices for a 3 bedroom house vs 4 bedroom house”.
Smoke-day operation doesn’t require a new system, but good filtration, correct duct design, and correct control settings matter.
Over 10 years, is ducted AC or multiple split systems cheaper for a 3-bed Sydney home?
Target audience
This is for anyone with central air conditioning Sydney style ducted systems, plus either:
HRV/ERV ventilation, or evaporative cooling (or both).
It’s also for families in apartments, double storey homes, and tight terrace houses—because each behaves differently in smoke.
3) Design & Build Quality
On smoke days, the “build quality” that matters most is not what you see on the brochure.
It’s the invisible stuff: duct sealing, return air placement, and whether your home can be made “mostly closed” for a few hours.
Ergonomics/usability (smoke-day friendly controls)
A good setup passes the “sleepy parent test”: you should be able to switch to smoke-safe settings in under 30 seconds.
If your controller has a setting like Fresh Air, Vent, Outside Air, or Economy Ventilation,
you need to know where it is—because it’s the first thing to turn off when smoke hits.
HRV = Heat Recovery Ventilator (brings outdoor air in, exhausts indoor air out, transfers heat).
ERV = Energy Recovery Ventilator (similar, but also transfers moisture/humidity).
Both can be great for freshness—but smoke is still smoke.
4) Performance Analysis
4.1 Core Functionality: the safest “Smoke Day Mode” for ducted air conditioning Sydney homes
Here’s the simplest mental model:
On smoke days, you want your home to act like a “closed box” for a while.
Your ducted air conditioner should mostly move the same indoor air around (cool/heat it), not import outdoor air.
Interactive: Smoke-Day Mode Wizard (2 minutes)
Tip: Once you generate it, screenshot it for the next smoke day.
Interactive: “Clean-air room” energy saver
On smoke days, zoning helps you stay comfortable while running fewer rooms.
This can lower ducted air conditioning running costs Sydney-wide during long smoke events.
Real-world testing scenarios (Sydney stories)
Story #1 (Inner West terrace): A family told us their “ducted AC is making the house smell smoky.”
The fix wasn’t magic. We did three boring things: replaced/cleaned the return filter, confirmed the system was on recirculate (no outdoor air),
and created a single living-area “clean-air room” using ducted air conditioning zoning Sydney settings.
The smell dropped fast because they stopped importing smoke and stopped letting the system “breathe” through leaky doors/windows.
Story #2 (North Shore double-storey): A home had an ERV running in the background, doing its job: bringing fresh air in.
On normal days, that’s great. On heavy smoke days, it became a problem.
We showed the household how to pause/limit intake during peak smoke, then “air out” briefly when outdoor air improved.
Comfort stayed stable, and indoor irritation reduced.
follow health guidance and seek medical help if symptoms worsen. On the worst days, your clean-air room matters more than perfect temperature.
4.2 Key performance categories (what “safe” actually means)
Category 1: Keep smoke out (pressure + intake control)
- Close up: windows/doors shut. Use towels at door gaps if needed.
- Ducted AC: set to recirculate / reuse air (turn off any outside air / fresh air function if present).
- HRV/ERV: reduce or pause outdoor intake during heavy smoke (or use a “smoke mode” if your model has it).
- Evaporative cooling: do not use during smoke. It relies on pulling outdoor air in.
Category 2: Filter the air you keep inside
Your ducted air conditioner has a filter, but smoke events can be intense and long.
The practical play is: create a clean-air room and consider extra filtration in that room.
(If your ducted filter is overloaded, the system can lose airflow and feel weak.)
Category 3: Don’t forget ventilation forever (CO₂ and comfort)
If smoke lasts a long time, a fully sealed home can feel “stuffy.”
The safest compromise is short, controlled ventilation when outdoor air quality improves—even temporarily.
That might mean a short HRV/ERV cycle at the best moment of the day, then back to sealed mode.
5) User Experience
Setup / installation process (what to check before smoke season)
- Locate your controller setting for recirculate / reuse air.
- If you have an outdoor intake on the ducted system, confirm how to disable it on smoke days.
- Confirm HRV/ERV controls: can you reduce intake, pause, or run “boost” for short periods only?
- Pick a “clean-air room” (often living area) and learn your zoning buttons.
- Book a pre-season service if airflow is weak or the system is noisy:
ducted air conditioning service Sydney (repairs & service)
.
Daily usage (a simple smoke-day routine)
1) Check local air quality updates.
2) Close windows/doors. Stop indoor smoke sources (candles, incense).
3) Set ducted AC to recirculate and run only needed zones.
4) Pause/limit HRV/ERV outdoor intake during heavy smoke.
5) Don’t run evaporative cooling while it’s smoky.
6) When air improves, do a short “fresh-air reset”, then seal again.
Learning curve
Most people master this in one smoke event. The real key is knowing your own buttons:
recirculate, fresh air off, zone on/off. Once you know them, it’s easy.
Interface/controls: the “30-second switch”
If you can’t switch modes quickly, the system won’t help you when the haze rolls in.
If you want KYC to label zones and show your household the fastest routine, that’s part of many
ducted air conditioner installation
and tune-up visits.
6) Comparative Analysis
Ducted air conditioning vs HRV/ERV vs evaporative (on smoke days)
| System | What it’s best at | Smoke-day risk | Smoke-day setting |
|---|---|---|---|
| Ducted Air Conditioner (refrigerated / reverse cycle) | Cooling + heating the whole home | Low (if recirculating) | Recirculate / reuse air, zones only |
| HRV / ERV | Fresh air + controlled ventilation | Medium–High (it can import smoke) | Reduce intake / pause during heavy smoke; short cycles when air improves |
| Evaporative cooling | Efficient cooling in dry conditions | High (needs outdoor air) | Off when it’s smoky |
Unique selling points (why ducted wins on smoke days)
- Recirculation means you can cool/heat while keeping smoke out.
- Zoning means you can protect one area first (clean-air room).
- Comfort reduces the temptation to open windows “just to breathe.”
When to choose this over “fresh air” strategies
If the outside air is truly bad, comfort + sealing becomes the safest baseline.
Fresh air can come later, at the best time of day, in short controlled bursts.
Watch: quick explainers (YouTube)
7) Pros and Cons
What we loved
- Fast comfort without opening windows (when ducted AC is in recirculate mode).
- Zoning makes a clean-air room easy and cheaper to run.
- Simple routine your household can actually follow.
Areas for improvement
- Filters can clog fast during smoke events; you need to check them more often.
- HRV/ERV controls are confusing on some models—people accidentally leave intake on.
- Long smoke periods can make a sealed home feel stuffy (you need “safe airing” windows).
8) Evolution & Updates (2026 smoke guidance)
The biggest 2026 update is how consistent the advice has become across agencies:
use reverse cycle / ducted refrigerated systems on recirculate, and
avoid evaporative coolers during smoke. The nuance is ventilation:
HRV/ERV is helpful for normal indoor air quality, but on heavy smoke days you must manage outdoor intake.
9) Purchase Recommendations
Best for
- Homes that want whole house air conditioning Sydney comfort during smoke events.
- Families who can use ducted AC zoning systems to create a clean-air room.
- People who want one system for ducted heating and cooling Sydney year-round (reverse cycle).
Skip if
- You rely only on evaporative cooling and cannot close windows/doors (smoke will get in).
- Your ducted system has poor airflow or is overdue for service (fix that first).
Alternatives to consider (within your setup)
- Clean-air room strategy: even with existing gear, zoning + sealing can be your “smoke shelter”.
- Ventilation timing strategy: HRV/ERV short bursts only when outdoor air improves.
10) Where to Buy
If you want this done properly—setup, airflow checks, controller guidance, and smoke-season readiness—book with
KYC Air Conditioning Sydney:
Ducted Air Conditioning Installation (Sydney)
— ideal if you’re planning a new ducted air conditioner installation or replacement.
Ducted Air Conditioning Repairs & Service
— best for “ducted air conditioning not cooling properly”, smoke smell issues, noise issues, or airflow problems.
Long-term cost comparison guide (ducted vs splits)
— helpful when weighing ducted air conditioning replacement cost and running costs.
11) Final Verdict
Overall rating: 9.2/10 (for smoke-day safety when used correctly)
Bottom line: On bushfire-smoke days in Sydney, a ducted air conditioner running on recirculate with smart zoning is one of the safest,
most comfortable ways to ride out poor air—as long as you manage HRV/ERV outdoor intake and keep evaporative cooling off.
12) Evidence & Proof (2026-only)
2026 public guidance (the “don’t-import-smoke” rule)
- Recirculate indoor air during smoke events and avoid evaporative coolers because they bring outside air inside.
- Close windows/doors during short episodes; air out when conditions improve.
2026-only customer review snippets for KYC Air Conditioning Sydney
Amy Sarra (review timestamp: 12 Jan 2026)
“KYC were professional and installed our ducted system perfectly… the results speak for themselves. Highly recommended…”
Ducted install
Anthony Lieberman (review timestamp: 21 Jan 2026)
“KYC Air Conditioning did an excellent job installing our ducted aircon… tidy… answered all our questions… great communication.”
Customer care
Extra proof: want a zoning-first smoke strategy?
Zoning is not just for power bills. On smoke days it helps you create a clean-air room fast.
If you want the deeper zoning strategy (and a savings calculator), read:
How should I use zoning on ducted air conditioning Sydney homes to seriously cut power bills?
