How does an igloo keep you warm?

Harpreet Thandi

The igloo, iglu ᐃᒡᓗ comes from the word Inuktitut often translated as “snow house” widely used to describe any type of house, including traditional tents, sod houses, and modern buildings. The Igluvijaq ᐃᒡᓗᕕᔭᖅ refers to the igloo specifically made from bricks of snow. This acts as a perfect shelter in conditions where snow is plentiful.

In terms of architecture, the igloo is constructed as a catenary, built in a spiral direction. This building method creates a self-supporting structure that balances the force on each brick evenly. The catenary shape is a very solid structure that allows the weight to be distributed.

However, without further work, the igloo is weak. A stone lamp can be placed inside, causing snow on the inside to melt. The temperature varies from -7C0 to 16C0 compared to the outside where the temperature is much lower at -45C0. This temperature gradient creates transitions between ice and snow making the igloo stronger. If done correctly, an igloo can support even the weight of a person standing on the roof! A ventilation hole is put in to allow this temperature shift and the passageway and storage act as a cold trap. This keeps the living and resting area warm for people to live in and allows the transfer of heat.

Inside an igloo, heat can transfer via three methods; conduction, convection, and radiation. Our bodies are an example of radiation as they transmit heat to the insides of the igloo, making it warmer. Convection acts like a current, allowing this radiated heat to circulate on the inside of the igloo, increasing its internal temperature. Conduction occurs when heat travels through a medium like the surface of an igloo. The ventilation hole, mentioned earlier, allows excess convection currents to leave the igloo and for heat to transfer. This hole also acts as a window. The igloo’s entrance allows cold air to be part of the igloo by lowering the temperature but keeping the living area warmer which is higher up.

Snow acts as an insulator due to the amount of air that forms between the spaces in the crystal structure of the snowflake. 95% of these crystals contain air within the structure that can trap heat, greatly reducing the amount of heat lost.

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