Rabbit hutch tiny house

Overview

• Rabbits cannot tolerate temperatures greater than 30 degC, this is why they live underground.
• In this project we experiment with the six Passive House principles to keep internal temperatures as constant as possible.
• The six Passive House principles are:
  • air tightness - air leaks result in excessive temperature gains or losses
  • insulation - stops thermal leakage through roofs, walls and floors
  • thermal mass - slows heat gain or heat loss
  • double glazed windows - is the equivalent of insulation for windows
  • north facing windows for heat gain
  • eliminating thermal bridges

Discovery learning experiments

• In this project we will experiment with a foam box that we can modify using the six Passive House principles.
• To monitor the effects of the six Principles we will use a temperature sensor

• We will also include two controls:
  • one temperature sensor in an unmodified foam box
  • one temperature sensor measuring atmospheric temperature changes

• Because we can't control experimental conditions we will just need to monitor the performance of our experiment over several weeks.

Experiment 1 - air tightness

• Using PVA glue, paint the inside and outside surfaces of the foam box with two coats of PVA glue
• Foam often has small micropores that allows air to pass through
• We call this an open foam structure
• Once dry, the PVA coating should help create a box that is more air tight.
• This should improve thermal performance in comparison to the two controls.

Experiment 2 - insulation

• The foam box already has walls of foam which functions as insulation.
• Foam acts as an insulator because air is trapped within the foam, and also because foam itself is a poor conducted on heat.
• The thicker the walls the better the insulation properties.
• Another way to improve insulation is to add some more insulation to the outside of the box.
• Some experimental suggestions include:
  • Adding foam or other insulation materials to the outside of the box.
  • Placing the original foam box inside a bigger foam box.
  • Replacing the original foam box with a foam box with thicker walls.
  • Wrapping the foam box in insulation material

• Check to see how temperatures rise and fall with the addition of insulation outside the foam box.

Experiment 3 - thermal mass

• Thermal mass slows the effects of heat gain or heat loss
• Dense materials have thermal mass such as concrete, metal, bricks and water.
• During the day high thermal mass absorbes excess heat. This prevents inside temperatures from rising too fast.
• During the nigh, high thermal mass material release their stored heat.

• Some experimental suggestions include:
  • Adding a plastic water bottle filled with water inside the foam box.
  • Adding a brick inside the foam box.

• Thermal mass can also be added outside the foam box.
• One option is to dig a hole and place the foam box inside the hole.
• This option is similar to a rabbit burrow and may help explain why rabbits prefer living underground.

• Check to see how temperatures rise and fall with the addition of thermal mass inside the foam box.