Understanding How Snow Can Keep You Warm

Introduction

• Snow is seemingly contradictory in that it is frozen yet can keep you warm.
• Animals burrow into snow, and Inuits have used igloos for warmth for centuries.

Igloos vs Quinzy

• Igloo: Constructed with snow blocks stacked in an upward spiral using existing snowpack.
• Quinzy: Resembles a snow cave; snow is piled and packed before hollowing out.

Thermodynamics of Heat Transfer

• Cold is the absence of heat; heat is the jiggling of particles.
• Heat Production: Your body creates heat by converting calories into energy.
• Heat Leaving the Body: Causes a sensation of coldness.
• Three Ways Heat Transfers:
  • Radiation: Heat radiates off your body.
  • Convection: Heat moves around inside the igloo.
  • Conduction: Heat is lost through the igloo walls.

Insulation and Air Pockets

• Insulation: Prevents or slows heat transmission.
• Air Pockets:
  • Solid objects transfer heat via conduction.
  • Air particles, spaced apart, transfer heat by convection.
  • Snow traps air, preventing movement and conducting heat poorly.

Properties of Snow as Insulator

• Snow comprises about 95% air.
• Snow’s insulation properties require direct contact for melting.
• Melting snow for water is slow without direct contact or a small amount of water to start.

Temperature Differences

• Igloos are cooler than insulated homes but can be 40 to 60 degrees warmer than outside.
• Example: 37°F inside vs 12°F outside, demonstrating a significant difference.
• In colder regions like the Arctic, the difference is even greater.

Igloo Design Principles

• Hot Air Rises: Igloos use raised platforms to capture warm air.
• Cold Air Trapping: Doors are lower to trap cold air.
• The design aims to trap heat and minimize escape.

Sources of Heat in an Igloo

• Body heat raises the igloo temperature over time.
• More people inside means more warmth.
• Additional heat source: a small lantern can help increase warmth.

Conclusion

• Igloos, though not "hot," offer significant warmth compared to outdoor conditions.
• Utilize principles of thermodynamics and igloo design for survival in cold environments.