From the beginning, homes have been marvels of human engineering. These are the places we lay our heads, and we are continually working hard as a race to find new and better ways to stay comfortable indoors. Innovations came slowly, then all at once, with miracles like windows and air conditioning now accepted as commonplace.
But in NZ, there’s one piece of in-home engineering that isn’t widely in place: home ventilation systems. In our quest to create the most energy-efficient and well-insulated homes we could, we collectively built a bottleneck. By sealing our homes so tightly against the elements, we’ve stopped them from breathing.
As a result, New Zealanders have a long history of dealing with damp, mouldy homes, often caused by a lack of ventilation and persistently damp weather. These systems aim to change that for everyone, from occupiers of the oldest heritage homes to builders of the newest developments. So, let’s talk about home ventilation systems: what they are, how they work, and the benefits of installing one in your home.
A home ventilation system provides a mechanical series of ventilation pathways to consistently replace stale indoor air with fresh outdoor air. It helps your home to ‘breathe’, in a sense. Just as your body needs to expel carbon dioxide to take in oxygen, your home needs a way to expel moisture, CO2, and airborne pollutants while cycling in fresh air.
Historically, Kiwis have relied on what we’ll politely call natural ventilation (a.k.a. old villas built fairly drafty). The gaps in the floorboards and the loose-fitting windows did that ventilation work for us, but also let the cold in. Nowadays, we’ve nailed temperature regulation, but the double glazing and high-spec insulation trap all the indoor air. There’s very little natural cycling of air.
Modern home ventilation systems provide an easy way to enjoy controlled, filtered air in your home without constant energy output.
Let’s pull back the curtain on the physics here, because there is a lot of science involved in making home ventilation systems work.
There are different types of home ventilation systems, so for the purpose of this explanation, we are just going to focus on the two most common in New Zealand: Positive Pressure and Balanced Pressure.
Across both types, the goal is to remove stale air and replace it with fresh air, all without disturbing your home’s carefully maintained temperature or sending your energy bills into the stratosphere. Here’s how they do it.
Positive-pressure home ventilation systems are the most common we install. They work by drawing air from your roof cavity (the space behind your ceiling, before your roof deck), and they do this for a specific reason.
To create positive pressure, we install a fan unit in your roof space to draw in outside air. These units are very quiet and super energy-efficient, usually costing you no more than running a single lightbulb. That air is drawn in and filtered through a high-grade filter, usually HEPA-grade, that strips away all of the dust, pollen, mould spores, and other pollutants you might be dealing with.
That filtered air is then pushed through your home via a series of ducts attached to different points of your ceiling, usually prioritising the living spaces. As that fresh air is pushed in, it creates what we call ‘positive pressure’, which gently forces the old, stale air out through the natural gaps in your home. This is why we generally recommend this model for most homes, as many have one or two ventilation-friendly gaps that can make the most of this system.
That said, there are some hyper-sealed homes that have almost nowhere for old, stale air to run. In that case, we would recommend a ‘Balanced Pressure’ home ventilation system.
Instead of a single fan, this system has two: one to pull in fresh air and one to push out stale air. There’s a critical piece of this puzzle hidden in a new component, the heat exchanger, which allows the warmth from the outgoing air to be transferred to the incoming fresh air. You get 100% fresh air without losing the heat your pump is working so hard to generate in your living spaces.
Home ventilation systems are the ultimate companion for any Auckland homeowner because they address the issues that old Auckland homes tend to have in spades. Some of the best qualities of a home ventilation system include:
So, if you’ve been struggling with a damp home, or you’re tired of allergens impacting your family each day, or you’re simply looking for a high-value way to upgrade your all-around comfort, home ventilation systems could be for you.
Hopefully, we have answered the important question here: what is a ventilation system? Now you can move forward better informed. We help Bay of Plenty homeowners across the region install high-quality home ventilation systems with no hassle or stress. Our experts are on-hand to help you decide on the best system for your home’s unique needs (and yours). Talk to us today about bringing some fresh air into your home.
