Ask most people why they installed a heat pump and they’ll say comfort. That’s fair, but it undersells things. The heat pump health benefits are the part worth paying attention to, because New Zealand houses have a long-standing habit of being colder and damper than they should be, and cold damp homes make people unwell.

This isn’t a marketing line. It’s the reasoning behind the Healthy Homes Standards, which set a legal minimum for heating in rental properties precisely because the health cost of cold housing is well documented. Below we’ve set out what cold does to a household, what a heat pump actually changes, and what the rules require if you’re a landlord.

Why Cold, Damp Homes Make New Zealanders Unwell

The World Health Organization recommends a minimum indoor temperature of 18°C for healthy adults, and warmer again for households with infants, older people, or anyone unwell. A great many New Zealand homes sit below that for large parts of winter, particularly in the bedrooms and particularly overnight.

Sustained cold indoors is associated with a measurable increase in respiratory infections and with worse outcomes for people who already have asthma or heart conditions. Cold air also holds less moisture, so a cold house pushes humidity onto the coldest surfaces — windows, exterior walls, the back of the wardrobe — where it condenses and, given a few weeks, grows mould. Mould spores are a recognised asthma trigger.

The unpleasant part is how self-reinforcing it gets. A cold room becomes a damp room, a damp room is harder and more expensive to heat, and the household responds by heating less and closing more windows. That cycle is the actual problem, and it’s the one worth breaking.

The Heat Pump Health Benefits That Actually Matter

Plenty of heating will make a room warm. What sets a heat pump apart, health-wise, is how it delivers that warmth.

It holds a steady temperature rather than swinging

Because inverter heat pumps modulate output rather than cycling hard on and off, they hold a room near its set point instead of overshooting and dropping away. Steady warmth above 18°C is what the health guidance actually asks for — not brief bursts of heat in the evening followed by a cold night.

It removes moisture while it runs

A heat pump in cooling or dry mode condenses moisture out of the air and drains it outside. Even in heating mode, simply lifting the room temperature raises the air’s capacity to hold moisture, which keeps humidity away from the dew point on cold surfaces. Less condensation means less of the mould that follows it.

It adds no moisture or combustion by-products

This one is underrated. An unflued gas heater releases water vapour and combustion gases directly into the room — roughly a litre of water for every litre of LPG burned. That’s why unflued combustion heaters and open fires do not qualify under the Healthy Homes heating standard. A heat pump adds nothing to the air it warms.

It filters the air it circulates

Heat pump filters catch dust, pollen and larger airborne particles as air passes through the indoor unit. This is useful for allergy-prone households, but only if the filters are actually cleaned — a clogged filter reduces both airflow and efficiency. It’s also worth being clear-eyed: a heat pump filter is not a medical-grade air purifier, and it isn’t a substitute for ventilation.

What the Healthy Homes Heating Standard Requires

If you own a rental, the heat pump health benefits above aren’t optional extras — a version of them is written into law. The Healthy Homes heating standard requires:

  • One or more fixed heaters that directly heat the main living room — portable heaters don’t count
  • A minimum capacity of 1.5kW, and enough total capacity to meet the calculated requirement for that room
  • A thermostat, if the heater is a heat pump or electric heater
  • No open fires and no unflued combustion heaters

There’s one rule that catches people out: if the required heating capacity for the main living room is over 2.4kW, you cannot meet it with a plain electric heater. Heat pumps are specifically exempt from that restriction, which is a large part of why they’ve become the default answer for compliance. Landlords who don’t meet their obligations can face financial penalties of up to $7,200.

Tenancy Services provides a free heating assessment tool for calculating the required capacity, or we can assess it on site. If you’re weighing up sizing more generally, our guide to what size heat pump you need walks through the same calculations for owner-occupiers.

Who Feels the Difference Most

Everyone gains from a home that holds 18°C, but the heat pump health benefits land hardest in some households:

  • Infants and young children — less able to regulate their own body temperature, and more susceptible to the respiratory infections that circulate in cold, damp housing.
  • Older adults — cold places additional strain on the cardiovascular system, and the risk of falls rises when hands and joints are cold and stiff.
  • People with asthma or COPD — cold air and mould spores are both common triggers, and reducing exposure to either tends to help.
  • Anyone recovering from illness — consistent warmth and decent sleep are basic conditions for recovery, and a cold bedroom undermines both.

If someone in your household falls into one of these groups, it’s worth heating bedrooms as well as the living room rather than treating the lounge as the whole job.

Getting the Health Benefits in Practice

Owning a heat pump and getting the full benefit from one aren’t quite the same thing. A few habits make most of the difference:

  • Set it and leave it. Around 18–21°C, running steadily, costs less and works better than blasting 26°C for an hour each evening. Inverter systems are at their most efficient holding a temperature, not chasing one.
  • Heat the bedrooms too. Most of the night is spent in the coldest room in the house. A living-room-only approach leaves the biggest gap unaddressed.
  • Clean the filters monthly through winter. Ten minutes with a vacuum. Dirty filters cut airflow, raise running costs and undo the air-quality benefit entirely.
  • Book a service annually. A regular maintenance check keeps the system efficient and catches drainage or refrigerant issues before they become expensive.
  • Deal with the moisture sources. Lids on pots, extractor fans running, washing dried outside where possible. Our guide to stopping condensation and dampness covers this in detail.

The One Thing a Heat Pump Cannot Do

A heat pump recirculates the air already in the room. It heats it, dries it and filters it — but it does not bring in fresh air, and it does not remove carbon dioxide, cooking odours or the moisture your household generates simply by breathing and showering.

That matters because the instinct in winter is to seal the house up. A well-heated but unventilated home can still end up stuffy and damp. The fix is either disciplined manual airing — windows open briefly on opposite sides of the house, even on cold days — or a home ventilation system that does it continuously without dumping your heat outside.

Talk to Us About a Warmer, Healthier Home

The heat pump health benefits described above all depend on the same thing: the right capacity, in the right room, properly installed. Whether you’re an owner-occupier tired of a cold lounge or a landlord working through Healthy Homes compliance, that’s what our team assesses on every site visit across Auckland.

See our heat pump installation options, or get in touch for a free assessment and we’ll run the numbers for your home. You can also call us on 0800 224 123.

Heat Pumps and Home Health FAQs

What are the main heat pump health benefits?

Steady warmth above 18°C, lower humidity and therefore less mould, no combustion by-products or added moisture in the room, and filtration of dust and pollen as air circulates. Together they address the cold-and-damp cycle that drives most winter health problems in New Zealand homes.

What temperature should I keep my house at in winter?

The World Health Organization recommends at least 18°C, and 20–21°C for households with infants, older people or anyone unwell. Running steadily in that range is both healthier and cheaper than heating in short, intense bursts.

Do heat pumps help with asthma?

They can help indirectly. By keeping a home warm and reducing the condensation that leads to mould, a heat pump removes two common asthma triggers, and its filters catch dust and pollen. It isn’t a treatment, and anyone managing asthma should follow their doctor’s advice — but a warm, dry home is a better environment for it.

Do heat pumps dry out the air too much?

In heating mode a heat pump doesn’t actively dehumidify, but raising the room temperature does lower relative humidity. Most New Zealand homes are too damp rather than too dry, so this is usually welcome. If a room does feel dry, running at a lower set temperature generally resolves it.

Does a heat pump meet the Healthy Homes heating standard?

Yes, provided it’s fixed, has a thermostat, and meets the calculated heating capacity for the main living room. Heat pumps are the most common way landlords meet the standard, particularly where the required capacity exceeds 2.4kW and plain electric heaters are not permitted.

Is a heat pump better for health than a gas heater?

For unflued gas heaters, yes — they release water vapour and combustion by-products straight into the room, which is why they don’t qualify under the Healthy Homes standard. A heat pump adds nothing to the air it warms.

Do I need ventilation as well as a heat pump?

Usually. A heat pump recirculates existing air rather than introducing fresh air, so moisture and stale air still need somewhere to go. Manual airing works if you’re disciplined about it; a ventilation system handles it automatically without losing your heat.