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  • It is said that dogs are man’s best friend, and here in New Zealand, you could also say dogs are a farmer’s best friend. Across New Zealand, there is an estimated workforce of 200,000 farm dogs! Farm dogs are valuable assets on the farm, and they need to be kept healthy in order to do their work well.

    Rights: Eric Hines, licensed through 123RF Ltd

    Sheep dogs at work

    Farm dogs are a vital part of farming in New Zealand. They require a significant investment in terms of training and keep.

    Across New Zealand, it can get pretty cold, especially at night – but imagine sleeping in a 44 gallon drum with no curtains or other insulation during a South Island snow storm! Seeing some of the poor housing dogs were living in gave retired Canterbury sheep farmer Tony Prentice the idea to build a dog kennel to keep his dogs comfortable and in better health.

    Don’t give your dog a bone, give him a decent home!

    Tony Prentice

    The concept

    At the time, 80-year-old Tony knew that a warm kennel is more comfortable for a dog – but it is important for other reasons, too. A warm, well rested dog eats less food, can work longer and is better able to heal more quickly from injuries and ailments.

    The ideal temperature for dogs is 10–26°C. Tony knew his kennel needed to be insulated and the insulation material had to be lightweight so the kennel would be easy to move.


    Tony’s first prototype was made from plywood. Unfortunately, the dogs ate the prototype!

    This highlighted the need for materials that the dogs could not chew to bits.

    Rights: Rosie Todhunter

    Tony Prentice with prototype

    Tony Prentice stands beside a second prototype that was to become the inspiration for the final Kelvin – The ThermoKennel.

    Inspiration came to Tony from the way farmers in the past had repurposed old 44 gallon petrol drums to make dog kennels. Tony’s next prototype was made from plastic 44 gallon drums. Fitting one inside the other created a layer of insulation between.

    Further development

    Tony Prentice didn’t live to see his kennel reach the marketplace. It was his grand-daughter Rosie Todhunter who took up his work and further developed the kennel for market.

    Rights: Kelvin – The ThermoKennel

    Kelvin – The ThermoKennel

    Kelvin – The ThermoKennel captures and retains a dog’s body heat through insulated walls, floor and door and promises to keep a dog at its ideal temperature in winter or summer.

    Rosie worked with her grandfather’s original design but streamlined it in order to keep costs down so the end product would be affordable. Rosie eventually settled on polystyrene as an insulation material. It is light, and it is resistant to bugs that might move in with the dogs.

    The second prototype was called the Kelvin – The ThermoKennel – named after the Kelvin temperature scale and kelvin measurement unit. The kennel has two layers of UV-resistant plastic insulated with 30 mm of polystyrene. The door is made of polyvinyl chloride (PVC) strips – like those used on walk-in freezers and coolstores.

    It's basically a chilly bin.

    Rosie Todhunter

    The polystyrene acts as an insulator, and the PVC door means that a dog’s own body heat raises the kennel’s temperature – the dog provides the heat, and the kennel just insulates it.

    Tests showed the temperature inside Kelvin – The ThermoKennel was at least 10°C warmer than the outside temperature.

    The insulation also helps to keep the kennel and dog cooler in hot summer months.

    Other important features of Kelvin – The ThermoKennel are the removable floor and drainage hole to make cleaning easy and a fully sealed roof that latches on and off. The kennel can be packed down to half its size for easy transport. It can also be attached to a dog run if desired by the end user.

    Rosie relaunched Kelvin – The ThermoKennel at the Fieldays Innovation arena in 2014, where she picked up a Grassroots merit award.

    Insulation and states of matter

    Keeping warm involves stopping the transfer of heat from one object to another. This can be done by insulating the object. Materials can be either conductors or insulators of energy. Learn more about the ‘states of matter’ concepts insulation and heat transfer.

    Activity idea

    House an animal
    Invite your students to design a home for their pet or chosen animal. They will need to research the needs of the animal and the conditions of the environment it lives in before they commence their design. Students could also identify and test materials and build a working prototype. Younger children might draw up plans or build a model.

    See the range of interesting resources in our Dogs, cats and science Pinterest board.

    Useful links

    ThermoKennel has teamed up with Locus Research and developed a third prototype. In August 2018 they launched a kickstarter crowd funding campaign to raise funds to commence production. Read more in the article here.

    Download an article about insulation, with accompanying teacher materials, from Connected 1 2010 – Staying Warm, Keeping Cool.

    Find further resources on the scientific concept of thermal insulation on TKI in Insulation: Keeping Heat Energy In.

      Published 2 August 2016, Updated 6 September 2018 Referencing Hub articles
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