SOLAR HEAT AND RADIANT HEAT
- Electromagnetic radiation (EMR)
- Kinetic energy
EMR is the type of energy we receive from the sun and has several different levels of intensity as illustrated below. The energy moves in oscillating waves; the more oscillations or waves per second, also referred to as frequency, the higher the intensity of the energy. Most of the electromagnetic frequencies are undetectable to humans, however, our senses can detect some ranges of EMR; visible light and infrared rays (referred to as radiant heat or just heat).
- Visible light is light within the visual perception of humans.
- Infrared radiation (IR) is a form of EMR humans senses perceive IR as heat.
The high energy spectrum, such as gamma rays, x-ray and ultraviolet can be damaging to our bodies as they have the ability to penetrate through and into our bodies. The damaging high energy Gamma, X and ultraviolet radiation are mostly absorbed by the earth’s atmosphere and converted to less energetic forms of EMR such as visible light and infrared rays. A sunburn is caused primarily by ultraviolet rays which escape being absorbed in the atmosphere and make it to the earth’s surface. Low energy EMR rays such as radar, FM shortwave and AM are the energy waves we use for communications; they also continuously bombard our bodies but at natural occurring intensities have no physical impact.
Spectrum of Electromagnetic Radiation
Electromagnetic radiation has the ability to travel through a vacuum. This is how the suns energy reaches the earth. The energy that most effects the earth’s surface temperatures are in the visible light and infrared spectrum of electromagnetic radiation. So we know the sun emits electromagnetic radiation because we can see it and feel it. Here’s where it gets interesting… all matter above the temperature of absolute zero (-459.67˚F) emits electromagnetic radiation. So everything around us is constantly exchanging electromagnetic energy at the speed of light, even an ice cube. You can feel the heat from a burner on a stove; that is infrared electromagnetic radiation (heat). If you turn the stove element to high it will also glow red at which point it is radiating both infrared heat and visible electromagnetic radiation (light). When electromagnetic radiation strikes a surface (including our bodies) some is absorbed and some reflected. We often use the terms hot or cold to define a temperature; hot and cold however are only terms relevant to our senses. If we stand in a corner of a room next to a operating wood stove we feel warm. If we walk away from the stove to window or door in the winter we feel cold. What is occurring is the window is radiating lower energy electromagnetic infrared heat and our bodies sense the difference, however the window is still radiating heat, just a lot less than the wood stove.
HOW THE THERMAL WALL TECHNOLOGY WORKS:
Wood-Stove Providing Radiant Heat
From the example above imagine you are standing next to a 4ft square wood stove radiating enough heat at 250°F to heat a room 16ft by 16ft. The 4ft square wood stove has six sides making the total surface 4ft X 4ft X 6-sides = 96 square feet. The amount of heat radiated from the stove is a function of the temperature (250°F) and the amount of surface area (96 square feet) radiating heat. If the wood stove was only 1ft square and radiated infrared heat at a temperature of 250°F the room would be cold, however, if the stove were 8ft square at 250°F the room would overheat. This example illustrates that as the surface area of the radiating source increases the temperature must be reduced. Now imagine the heat is radiating from the walls and floor of the 16ft by 16ft room. This provides 768 square feet of heating surface and represents 8-times the surface area of the wood stove. Because of this principle the area of the walls and floors enables the heating of the room at a much lower temperature, as illustrated below, creating numerous efficiencies.
Providing Comfortable Heat for Your Home
Another way to view this is if you were in a concrete room and the walls were maintained at 70⁰F and the only heat loss from the room was whatever your body produced; the temperature of the room would be 70⁰F. So the temperature of the walls in the TWT whether heating or cooling will basically feel very much the same temperature (perhaps slightly warmer or cooler) than the walls in a conventional home.