How to build a house and keep it cool
CONVECTION! Design + build a house with doors and windows that will help remove the hot air and cool the house passively (without using a fans or the AC). The goal is to save energy.
COLLECT
CONSTRUCTION PAPER
TAPE
SCISSORS
TWO INCENSE STICKS & holder
ONE MATCHBOX
THERMOMETER
If you have an attic space or have ever been in an attic space on warm days, have you noticed how much warmer it is in there than in the rest of the house? How about in the basement? In the days before refrigerators, basements - because they are much cooler - were used to store food items. Next time it's hot inside, try lying down on the floor and see how you feel. It's cooler than when standing up, isn't it?
Warm air rises to the top because it is lighter, or less dense, than cold air. Air molecules with more heat, or energy, move around at greater speeds and end up farther apart. So in the same amount of space (volume), warmer air will have less molecules in it than colder air. This makes it less dense or lighter, and it makes it rise up.
As warm air rises and cold air sinks, a directional movement of air is created which is called a convection current.
Have you ever wondered why on a warm day it is warmer inside a parked car than outside? This concentration of heat inside the car is caused by the greenhouse effect. A greenhouse is an enclosure made of glass or other transparent materials - typically for plants - that allows sunlight in, but then traps some of the sunlight's energy inside. This trapped energy is heat. A car parked in the sun heats up for the same reason, heat energy from the sunlight gets trapped.
Experiment
1. Knowing that warm air rises and cold air sinks, can you think about which parts of your house are the hottest? Sketch and design the location of your openings (doors and windows) so that the heated air will come out and the cool outside air will come in.
2. Build your cool house out of construction paper.
3. Once the house is complete, put a lit smoking incense stick inside the house in an incense stick holder.
BE CAREFUL NOT TO TOUCH THE PAPER WITH THE INCENSE STICK AND SET IT ON FIRE!
If the placement of windows and doors is well designed for cooling with natural ventilation, then the smoke will come out.
4. Place a thermometer at various points inside the house. Where do you get the highest reading?
Reflect
What design worked best?
What placement of openings helped more smoke to get out of the house?
Where did you get the highest temperature reading?
Why do you think this is?
Can you think of some other examples of convection you can see around the house?
Original Post by : http://curiositymachine.org
