When you visit a New Zealand home show, the orange and blue stands catch your eye right away. The idea is straightforward: choose a brand and your damp problems should get better. That’s why so many people look up dvs vs hrv, most of us just want dry windows, fresher rooms, and less stress about mould.
Every week, we talk to people from Tauranga, Mount Maunganui, Papamoa, and the wider Bay of Plenty. Many have the same issues: wiping away condensation in the morning, dealing with musty wardrobes, or noticing the air feels heavy when the house is closed up at night. In this guide, we’ll break down what’s behind the brands, where positive pressure systems work best, when heat recovery might be a better fit, and how to pick a setup that suits your home and lifestyle.
Let’s get clear on the core technology, because this is where confusion often sits. Traditional DVS and HRV units are positive-pressure systems. The building regulator describes these as roof cavity approaches that push filtered air into living spaces, to force stale air out through gaps, windows, and doors. HRV explains the same idea in its own guidance.
So when you read about dvs vs hrv, remember you are mostly comparing two takes on the same method.
A positive pressure system takes air from your roof space, runs it through filters, and sends it down ducts into key rooms. The unit keeps the house at a slightly higher pressure than the outdoors. That gentle pressure difference pushes damp, stale air out through natural leakage points.
If you grew up in an older timber home, you already know how much air slips in and out through floorboards, sash windows, and loose door frames. Positive pressure uses that natural leakiness to its advantage.
Positive pressure systems often do a solid job in:
There are limits, and it is better to know them up front.
Positive pressure works well for older, drafty homes like villas and bungalows, where roof spaces stay dry, and air can escape through natural gaps. This helps reduce winter condensation and keeps rooms feeling fresh. In newer, more airtight houses, though, this method may not be as effective, especially if the roof space gets hot in summer or collects dust and fibres, since the system uses that air. That’s why results differ from house to house. We always tailor the setup to your home’s layout and adjust vent positions and airflow, instead of assuming one brand or method fits every home.
Now for the part people expect. If you compare a standard DVS unit and a standard HRV unit, you will see differences in controls, filter options, and add-ons. One might use wool-based filters, while the other uses a nano-fibre style filter. Control panels look different, and each brand has its own way of showing temperature and fan speed.
The mechanics, though, stay similar. Both draw air from the roof cavity and supply it into the home. So if you are choosing strictly between these two for a positive pressure setup, the choice often comes down to price, warranty support, and who you trust to install and service it long term. Put simply, the dvs vs hrv decision is not a huge jump in technology for most standard homes.
If positive pressure feels like the only thing on the market, you are not alone. Yet many homes now suit a different approach, called balanced pressure heat recovery. Mitsubishi Electric’s Lossnay is a well-known example in New Zealand. It brings fresh outdoor air in, filters it, and extracts stale indoor air at the same time, transferring heat between the two air streams.
This option is sometimes left out of franchise conversations because it needs more planning. When people ask us about the best home ventilation systems in NZ, this is usually the type of technology they have not been shown. Still, for the right house, it can be the better fit.
Balanced pressure heat recovery uses two fans that work together. One fan pulls damp, stale air from bathrooms, kitchens, or hallways, while the other brings fresh outdoor air into living rooms and bedrooms. Inside the unit, a heat exchanger transfers warmth from the outgoing air to the incoming air, so you keep more of the heat you have paid for. Over winter, this can lower heating costs, especially in homes that stay well-heated.
In the Bay of Plenty, heat recovery often suits modern or renovated homes because it does not rely on roof space air and handles tighter buildings better than positive pressure. Fresh air comes from outside, so it feels cleaner and more consistent. The heat exchange helps hold warmth in cooler months and eases summer humidity. For coastal homes, where muggy spells can leave rooms damp even when doors stay shut, this direct extract and supply approach can control moisture more reliably.
We usually consider this option for new builds that follow current building code practice and are more airtight. We also see strong results in homes that had double glazing or insulation upgrades, because these changes reduce natural airflow. Families who want steadier indoor air for comfort, allergies, or asthma often prefer this path.
This is why we say the real question is not only dvs vs hrv, but also what kind of technology your home needs.
People sometimes ask this with a bit of hesitation, because a ventilation upgrade feels like a big spend for something you cannot always “see.” You may ask yourself, Are home ventilation systems worth it, after another week of wiping windows. The short answer is yes, a well-designed system makes sense for many homes here.
New Zealand has a high rate of respiratory illness. About one in six New Zealanders lives with a respiratory condition, and damp, mouldy homes can make symptoms worse. Public health guidance links dampness to mould growth and increased asthma triggers.
A good setup helps because it clears moisture and improves filtration. When indoor air has less dampness, mould spores and dust mites have a harder time taking hold. For parents, this can mean fewer coughs in winter or less waking up with a blocked nose when pollen sits in the air. For older adults, it can mean joints feel less stiff in the morning, because rooms stay drier and easier to heat.
Moisture not only affects people. Over time, it can affect plasterboard, framing, and even floor coverings. We have seen window sills that stay wet all winter, then start to soften. We have also seen garages and spare rooms develop a smell that never quite leaves, because damp stays trapped in linings. Keeping the home drier protects the asset you work hard to own.
Comfort is the part people notice first. If you have ever stepped out of bed to a cold puddle on the window ledge, you know how draining that routine feels. A house that dries out overnight is easier to heat, and it feels lighter to live in. Even simple changes, like not having to keep a towel by the bedroom window, can make mornings calmer.
That is the lived reality behind the search for DVS and HRV.
Once you know the technology options, the next step is who designs and installs them. In our trade, the installer matters as much as the box on the ceiling.
Many franchise models rely on sales staff who follow a set script and sell a standard kit. That approach can work fine in a straightforward, older house. Yet it can miss details that change performance, such as where moisture builds up, how your ceiling space is shaped, and how air moves between rooms.
We are trade-qualified HVAC technicians with around 30 years of experience in heating, air conditioning, and ventilation. So when we assess a home, we look at airflow paths, roof conditions, existing heating, and the way your family uses the space. We then design the layout to suit. If you have a teenager who keeps their door shut all day, or a bathroom with no natural window, those points feed into vent placement and fan settings.
Because we are independent, we do not have to sell one sticker. We supply and service all major brands, and we choose based on fit for your home. Sometimes a positive pressure unit is the right call. Sometimes a balanced heat recovery unit fits better. The aim is not to win a brand contest, but to solve your damp and stale air problems. We will recommend a ventilation system that fits your home.
This is also where proper ventilation layout design comes in. We size airflow to the home, we plan supply and extract points, and we make sure ducts do not lose efficiency through poor routing. The system then works quietly in the background, without you needing to think about it.
If this guide leaves you with one clear point, let it be this: don’t get locked into the dvs vs hrv debate as if it is the only choice. Both brands use positive pressure systems that suit many older, leakier homes, yet newer or tighter houses often need a different approach. The right call depends on your house type, your layout, and where moisture builds in daily life.
When we assess a home, we trace the problem first, then match the technology to solve it, whether that is positive pressure or heat recovery. If you live in Tauranga, Mount Maunganui, or the wider Bay of Plenty, talk with us at Western Bay Air Conditioning for a free, independent quote. Choose the system that fits your home, and you will feel the difference every single morning.
There is no universal pick. The best option depends on your house type, how airtight it is, and where moisture sits. Positive pressure often suits older, leakier homes. Balanced heat recovery often suits newer or renovated homes. A site visit lets us confirm which path makes sense.
For many households, yes. They help control condensation, reduce mould risk, and make rooms feel fresher. The value is strongest when the unit is correctly matched to the home and maintained over time.
Cost varies with house size, number of outlets, and system type. A simple positive pressure setup tends to sit at a lower price point. Heat recovery units cost more because they include two air paths, a heat exchanger, and more ducting. We quote after measuring the home, so you are not paying for gear you do not need.
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