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Meet Mr Humfreez

The little ram that helps you know when your home is too damp or too cold.

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 between 18-21°C and less than 65% relative humidity. But the average home temperature in NZ is 17.8°C, with some as cold as 10°C. And due to excess moisture, half of all our 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.

How Mr Humfreez works


The 'hum' part: humidity sensing horns

His 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 is how his horns are programmed to uncurl at 65% relative humidity, when the air becomes unhealthy.

His 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.

'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.

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.

ANZ Healthy Homes

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

This material is for information purposes only. We recommend seeking financial advice about your situation and goals before getting a financial product. To talk to one of our team at ANZ, please call 0800 269 296, or for more information about ANZ’s financial advice service or to view our financial advice provider disclosure statement see