Can Air Purifiers Remove Odours? A Practical NZ Guide
Odours and chemical smells are one of the most common reasons people start looking into air purifiers. Whether it’s cooking smells, pet odours, smoke, or off-gassing from everyday products.
Air purifiers can help reduce odours and VOCs, but only when they’re used correctly and paired with the right type of filter. They’re also not a silver bullet, ventilation still plays a critical role.
This guide explains:
- What causes odours and VOCs indoors
- How air purifiers help (and where they don’t)
- What actually matters in a carbon filter
- How to set realistic expectations
Quick Summary: Air Purifiers and Odours
Odours are caused by gases (VOCs), not particles
HEPA filters alone do not remove odours
Activated carbon is required for odour and VOC reduction
More carbon = better performance (measured by weight)
Ventilation is still the most effective way to clear smells
Table of contents
1. What causes odours and VOCs indoors?
Most odours indoors come from volatile organic compounds (VOCs). These are gases released by everyday activities and materials.
Common sources include:
Cooking (especially frying, oils, spices)
Pet odours and litter trays
Smoke (fires, wood burners, tobacco)
Cleaning products and sprays
Paints, glues, sealants, and new furniture
Workshops, 3D printing, resin, and hobby spaces
Because VOCs are gases, they behave very differently to dust or pollen. This is why filter choice matters so much.
2. HEPA vs carbon: Why odours are different
This is a key point that’s often misunderstood.
HEPA filters capture particles like dust, pollen, mould spores, and PM2.5. They are excellent at this, but they do not remove gases or smells.
To reduce odours and VOCs, you need activated carbon filtration.
If a purifier doesn’t contain meaningful amounts of activated carbon, it won’t do much for odours. Regardless of how good other filter(s) are.
3. How carbon filters actually work
Activated carbon works by adsorbing gases onto its surface. The effectiveness depends on three main factors:
1. Carbon Form
Carbon pellets or granules are far more effective than thin carbon-coated meshes.
2. Carbon Quantity
More carbon means more surface area and longer‑lasting odour reduction. This is why carbon weight (grams or kilograms) matters.
3. Airflow (CADR)
A purifier needs sufficient airflow to pull odours and VOCs from around the room and pass them through the carbon filter. If airflow is too weak, much of the polluted air simply never reaches the filter.
This is a common issue with small or low‑powered purifiers marketed for odours. Even if they contain carbon, insufficient airflow means odours don’t get a proper chance to be treated.
4. Why "carbon filter included" often means very little
Many air purifiers advertise that they include a “carbon filter” or “VOC layer”, but in practice this can be:
- A very thin carbon sheet
- Only a small amount of carbon
- Designed more for marketing than performance
These filters may slightly reduce smells at first, but they saturate quickly and provide limited ongoing benefit.
5. Realistic expectations: what air purifiers can (and can’t) do
Air purifiers with proper carbon filtration can:
Reduce everyday odours over time
Lower background VOC levels
Improve perceived air freshness
They won't:
Instantly remove strong smells
Eliminate odours embedded in walls, carpets, or furniture
Replace ventilation
For persistent or strong odours, ventilation is still the most effective solution. That means opening windows and doors, or using mechanical systems like HRV, extraction fans and kitchen rangehoods.
6. Odours & VOCs in specific situations
Cooking Smells
Carbon filters can help reduce lingering smells, but kitchen extraction and ventilation remain important.
Pet Odours
Carbon helps with odours; HEPA helps with dander and allergens. To learn more, check out our article on purifiers and pets
Smoke Smells
Air purifiers can help with airborne smoke particles (HEPA filtration) and some smells. However smoke, especially from cigarettes often permeates furnishings and building materials. This means a purifier won't provide as much help when it comes to removing smells from a long term smoker house.
Workshops, resin, and 3D printing
Carbon filtration becomes much more important here. Many people underestimate how much carbon is needed for chemical vapours. For ongoing hobby or workshop use, larger carbon amounts and good ventilation are strongly recommended.
New home smells and renovations
If you’re dealing with new home smells, renovations, paint, or off‑gassing materials, we cover that in more detail in our dedicated article on new home smells and VOCs.
7. How our purifiers handle odours and VOCs
We focus on real, measurable carbon filtration, paired with enough airflow to actually circulate room air.
Smart Air Sqair
- Carbon filter included as standard
- 140g of carbon pellets per filter
- Additional carbon filters can replace the HEPA for heavier VOC use
- Add up to 5 extra carbon filters in total for increased odour reduction
Smart Air SA600
- 2x Carbon filters included as standard
- 170g carbon pellets per filter
- Can add 2 additional carbon filters for higher VOC loads
- Quiet enough to run continuously
Smart Air Blast Mini Mk II
- Optional carbon filter
- 550g carbon pellets per filter
- Quiet enough to run continuously
Smart Air Blast Mk II
- Optional carbon filter
- 900g carbon pellets per filter
- Quiet enough to run continuously
8. Carbon filter lifespan: a common question
Carbon filter lifespan is very difficult to estimate, as it can vary massively depending on:
- Type and concentration of VOCs
- Room size and airflow
- How often the purifier is running
In light odour environments, carbon filters may last many months. In heavier VOC settings (painting, resin, smoke), they can saturate much faster. Weaker carbon filters may only last a matter of hours in these situations.
Many people replace carbon filters when odours stop improving or based on the smell test
Final Takeaway:
Air purifiers can play a useful role in managing odours and VOCs - but only when they include meaningful amounts of activated carbon and enough airflow to circulate room air effectively.
For best results, pair air purification with good ventilation and realistic expectations.
Do air purifiers remove smells completely?
Air purifiers can reduce odours over time, but they rarely eliminate them completely. Strong or persistent smells often come from surfaces, furnishings, or building materials, which air purifiers can’t clean. Ventilation remains essential.
Do HEPA filters help with odours?
No. HEPA filters are designed to capture particles like dust, pollen, and smoke particles, but they do not remove gases or smells. Odour and VOC reduction requires activated carbon.
How much carbon do I need for odours?
There’s no single answer, but more carbon generally performs better. Purifiers with only a thin carbon layer may help briefly, while units with hundreds or thousands of grams of carbon provide longer‑lasting odour reduction.
Can air purifiers help with smoke smells?
They can help reduce airborne smoke particles and some smell, but smoke, especially from cigarettes often penetrates walls, carpets, and furniture. In those cases, air purifiers have limited impact on lingering odours.
