here's a previous experiment I found on the internet:

http://resources.metapress.com/pdf-preview.axd?code=12x2731203x0v876&size=largest

It tests the heat build up different colours of steel. The experiment was done in Australia and looked at 29 different colours of steel panels ranging from black to white. It was interesting to see the apparatuses used to complete the experiment. One apparatus used was a heat build up box which was used to predict heat build-up in paint films. A Tracrac was also used. A Tracrac is a 'racking system that follows the sun so that the surface of the painted panel is normal to the incident direct solar radiation'. Plywood was placed on the back of the steel to stop heat escaping from the back of the panels.

that's all for today :)

Hey, here is an overview of my experiemnt

Aim: to investigate energy efficiency of uninsulated steel roofing.

My experiment will be conducted in two parts;

Part A - Colour of steel.
I will test four or five colours of steel, by leaving them in the sun for a period of time (1 hour). I will test how much heat is absorbed by the steel.

Part B - Orientation and positioning of roof
I will test three different types of roof (e.g. flat roof, slanted roof) and leave in the sun for 4-6 hours. I will repeat this four times, for each direction the house can face ( North, South, East, West). I will observe how much sunlight is let into the house* and record the temperature of the house.

Independant Variables Include:

• Amount of time steel rooing is left in the sun
• Angle of roof
• Colour of steel

Dependant Variables Include:

• Intensity of sun
• Heat of steel
• Amount of sunlight let into house*

* My 'houses' will be small models I make. I know someone who is an architect and will be able to obtain the materials from him.

I did some research today,

http://www.colorbond.com/home/residential/roofing/thermal-efficiency

http://www.steelroofing.com/energy_efficient_choice.pdf

http://preengineeredsteelbuildings.net/news-society/energy-efficient-color-options-for-pre-engineered-steel-buildings/

http://www.resene.co.nz/homeown/probsolv/prob10.htm

Here's some info:

• Lighter colours radiate less heat during the summer.
• The sun is higher in the sky in summer.
• If your home faces true north, it will receive more sun.
• Eave-overhangs will prevent direct sunlight exposure in summer.
• "Cool" paint-based sun reflecting pigments act to reflect the infrared radiation.
• This means less solar energy is transferred throughout the home.
• Less heat, means less energy to cool and thus, reducing cooling costs.
• Reflectance is the amount of light reflected compared to the amount of light that falls on the given surface.
• Dark, matt and/or textured surfaces absorb a lot of light and have low light reflectance values. Light, glossy and/or smooth surfaces reflect most of the light that falls on them and have high light reflectance values.
• The higher the reflectance value, the less heat is transferred, home remains cooler.

I've had a new, completely different idea.
The most energy efficient uninsulated steel roofing. Well, it kind of stemmed from looking at energy efficient roofing and what I could look at/research. I decided that I needed to be more specific to reduce the number of variables (thanks miss Zhang). Eventually I came up with the idea of steel roofing.

I can look at two things:

• colour of steel - how much heat it absorbs, is the colour appropriate for both winter and summer, etc.
• Anlge/ positioning of roof - how much sunlight is let in, which direction is the best way for the roof to face, etc.

So yeh, this is my best idea so far..

still thinking...