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Breathe In, Breathe Out

Just like we do, our homes need to breathe to stay healthy. New Zealand has one of the highest rates of respiratory illnesses in the world. 70-80% of asthma in New Zealand is associated with allergies and many of these problems are linked to the moisture content of our homes.

Damp houses encourage the growth of moulds, fungi and dust mites which are a key factor in respiratory problems. Also, the quality of indoor air is becoming steadily worse as we create more tightly sealed homes in the name of comfort.

Stinky problem

Lingering bad smells in the bathroom and laundry and cooking smells in the kitchen are types of indoor air pollution and can indicate that ventilation in that area is not up to the job. Often opening a window is not enough. To address indoor air pollution, many countries insist on mechanical ventilation regardless of whether an opening window is available.

Although not a requirement in New Zealand, the trend to supplement opening windows with mechanical ventilation is increasing. In order to create a healthy environment for our families it is vital to ensure we have adequate ventilation in our homes.

Bad air out

Moisture build-up in wet areas can easily be prevented and controlled. Simple mechanical extraction such as rangehoods and extractor fans in kitchens, laundries and bathrooms take moist, foul air efficiently and quietly from your home.

They should always vent through a roof or wall to the outside of the home rather than to the inside of a wall or ceiling space where it may cause damage to the structure of the home over time.

Unseen dangers

Removing moist air from wet areas is a good start, but stale air should also be replaced with fresh air daily for a healthy home. Some of the contaminants that can build up in an unventilated home, making indoor air more polluted that outdoor air, are:

  • Volatile organic compounds (VOCs) from varnishes, paints, adhesives, synthetic fabrics, cleaning products, scents or sprays
  • Dust, including dust mite droppings and body parts, pollen and animal dander
  • Smoke from cooking, fireplaces, outdoor air or cigarettes
  • Carbon monoxide from cars idling in garages

For those with allergies, many of these pollutants produce eye, nose and throat irritation, skin reactions or asthma attacks. Even those who are allergy-free may experience headaches or drowsiness. On the extreme end, reactions can include vomiting and in the case of carbon monoxide build-up, even death.

Good air in

Have you ever lived in an unrenovated pre-1970s home? If so, you know how draughty they are. Older homes were not built to the same standards of insulation and energy efficiency as modern ones are. The up-side of old homes, although unplanned, is that the draughts provide passive ventilation.


Houses are now designed to be nearly airtight but achieving passive ventilation is still possible, although it has to be specified when you put in your windows.

Mechanical lungs

Costing just a few cents a day to run, mechanical ventilation is another great way keep fresh air circulating throughout your home all day, and it can provide other benefits too. All types of mechanical ventilation draw in filtered, fresh outdoor air, circulate the air continuously and reduce moisture in the home.

For those with allergies or close to busy, noisy roads, mechanically ventilated air can actually be healthier and quieter than opening a window.

Heat retention

Some mechanical ventilation units also contain a heat exchanging core, which extracts heat from the moist stale air it removes and transfers that heat to the fresh outdoor air it brings into the home. This retains existing indoor warmth while drying out the air in the home, making it easier to heat and thereby keeping heating bills down.

One room or many

There are a range of different mechanical ventilation products, ranging from Smartvent’s home ventilation system, to the Mitsubishi Electric Lossnay single room applications. Depending on the design of your house and whether or not you have a ceiling space, most can be either retrofitted or put in while the house is being built.

However you choose to ventilate your home, by replacing stale air with fresh, dry air you create a cleaner, healthier environment for your family.

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