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Coldness Alert.

Dampness Alert.

Cuteness Alert.

Meet Mr Humfreez.

We all want to live in a warm, dry home. 

Not many of us know the right temperature and humidity levels to create a healthy home. The World Health Organisation recommends a healthy temperature for a home to be between 18-21°C. But the average in NZ is 17.8°C, with some as cold as 10°C. And due to excess moisture, half of all Kiwis homes have visible mould.

That’s why we created Mr Humfreez, a little sheep that helps you understand the health of your home, by telling you at a glance when it’s too damp, or too cold.  Because a home should be more than a place to live, but to thrive.



Mr Humfreez goes blue in the face when the temperature dips below the healthy level of 18°C. 

He’s trying to tell us, "I’m freezing, please turn on the heating."


To prevent mould growth, the amount of moisture in your home (relative humidity) should ideally be below 65% most of the time. This is why Mr Humfreez warns you by uncurling his horns when the moisture in the air exceeds 65% (relative humidity).

It’s his way of saying, “it’s too humid in here, we need some fresh air.”

How Mr Humfreez works

'Nature Powered'

He’s a smart little sheep made from wood, ink and wool. And he doesn’t require any power to work. Watch the video to see what makes him tick.

The 'hum' part: humidity sensing horns

Mr Humfreez's specially designed wooden horns are ‘hygroscopic’ – meaning they can sense and react to moisture in the air. Wood does this naturally (ever notice how timber warps when wet?) The clever part about Mr Humfreez is how his horns are programmed to uncurl at 65% (Relative Humidity), when the air becomes unhealthy.

Mr Humfreez's horns are very sensitive and fragile. It’s best not to touch them, or they could break. (But you can give him a gentle pat on the back for being a good little sheep.)

The 'freez' bit: temperature sensitive face

‘Thermochromic’ ink on his face allows Mr Humfreez to react to changes in temperature. This specially made ink appears colourless when conditions are warm. When the room gets colder than 18 degrees, the blue ink shows its true colours.

How we made Mr Humfreez


Kiwi at heart, with global smarts.

We created Mr Humfreez to help Kiwis keep an eye on the health of their home. A digital thermometer/hygrometer would have done a similar job, but we wanted to make something that was smart and sustainable in equal measure.

The technology behind Mr Humfreez is the brainchild of Professor David Correa and his team at the University of Waterloo in Ontario, Canada.

They developed the programmable hygroscopic horns that allow Mr Humfreez to respond when the air gets too humid. And they helped formulate the special ink that makes his face change colour when it gets too cold.

Like many of us, Mr Humfreez is a global citizen with a Kiwi heart. He doesn’t go anywhere without his fluffy coat of NZ made merino wool.

ANZ Healthy Homes

If you think your home is too humid, or lacks adequate heating, check out our range of initiatives to Help Kiwis live in warmer, drier homes.

  • Interest-free home loan top ups for heat pumps and insulation.
  • Healthy Home Loan Package
  • HomeFit check.

Learn more