Which Air Conditioner is good to use during bushfire smoke conditions in Canberra and how to improve air quality

Below are some useful links get more information and keep yourself and loved ones safe.

Canberra Air Quality – ACT Health >

Emergency Services Agency updates >

How to protect yourself and others from bushfire smoke – Australian National University >

See how global warming has changed the world since your childhood – Australian Broadcasting Corporation >

The season of a smoky Canberra might be drawing to a close, but what about next time this happens? You don’t want to be at the mercy of the weather and a shift in wind patterns that bring in smoke that unhealthy for you to breathe in.

The Earth is slowly warming and wildfires are expected to become more prevalent in the coming decades. According an article published by the Australian National University breathing smoky air can irritate airways, and poses an especially serious risk to:

  • People who have heart or lung diseases, such as coronary artery disease or asthma.
  • Older people due to their increased susceptibility to heart and lung diseases.
  • Young children whose airways are still developing, and breathe more air, proportionally speaking, than adults do.
  • Pregnant women

What is in wildfire smoke?

Wildfire smoke is a shifting blend of gases and particles, including carbon dioxide, water vapor, carbon monoxide, hydrocarbons and other organic chemicals, nitrogen oxides and trace minerals. The worst part about smoke are the particulate matters, the tiny bits of feathery ash and dust-like soot, mostly invisible to the eye.

A lot of the particulate matter is less than 10 microns wide, known as PM 10. (A human hair is about 60 microns wide).

Avoid making your indoor air worse

You need to start by keep your windows and doors shut.

Your air conditioning unit is effective as a smoke filter, provided your house is well sealed against drafts and external air. Try to maintain the air quality inside by keeping openings secured and don’t smoke, burn candles, vacuum, or use your oven to avoid stirring up particles already inside your home. Turn bathroom fans and window units off.

Bathroom fans and window box fans commonly pull outside air into your home, so they should be shut off during smoky conditions.

Can I use my Air Conditioner while there is a lot of smoke outside?

In most cases, your home air conditioner recycles the air within the home. Every time the air passes through your air conditioning filter, the air is cleaned, and because there is no polluted air entering your home, the air remains quite clean and safe. If your air conditioner has a ‘Fresh Air’ function, you need to turn this off. This feature allows air from outside to enter the air conditioning system, any air drawn from outside risks bringing in bushfire smoke and the harmful contaminants you want to keep out.

Don’t use an evaporative AV during smoky conditions Evaporative systems draw air in from outside the house and push it through water-laden filter pads for cooling draw in other contaminants, such as smoke particles.

Now that you know what Air Conditioner unit you can’t use during a bushfire, what AC units can you use?

If your AC is a split system, an inverter or ducted system, you can use any of these when there is a lot of smoke present. While your outside unit expels a lot of hot air, that air isn’t coming from inside your home and being replaced with outside air. Air conditioners are heat exchangers. They use a closed coolant system to absorb heat from the air inside your home and use powerful fans to push a lot of outside air over that same coolant system, suck out the heat, and exhaust that heated air back outdoors.

If you have a heating system (gas furnace) or a cooling system you’re not currently using, turn the fan on at your thermostat. For the best possible air quality in your home, consider installing an electrostatic whole home air filter or heat recovery ventilator, which provides you with a continuous stream of fresh air.

A Split System –  the way split system air conditioning works is that the condenser sits outside and manages the heat expulsion, while the head unit inside the house re-circulates and manages the airflow and temperature. The condenser only manages external air so it has no capacity to draw smoke into your house. Having an inverter in your in your AC allows large units to ramp down and use little power when their load and capacity is not required.

Make sure you have the right filter Start by making sure you have a fresh filter for your system with a backup ready to go. To choose the right filter, consider the Minimum Efficiency Reporting Value (MERV) rating. Filters that are MERV 13-16 are expected to reduce indoor particulars as much as 95%. Filters with a High Efficiency Particulate Air (HEPA) rating, (or MERV 17-20) will reduce particulates in your home even more. You might also consider an air filter with activated carbon. Carbon air filters are designed to filter volatile organic compounds (VOCs) from gases in your home through a bed of activated carbon (also called activated charcoal).