Depending on where you live on the planet, the sun will seem hotter and have more strength from different directions. If you live in the very northern hemisphere, the winter sun is from the south. If you live in the most southern hemisphere the winter sun has strength from the north . If you live on the equator than the sun is strongest directly overhead and doesn’t change all that much during the year. It is obvious when you think of it, that the biggest glass windows should be on the sunny side for the best winter sun collection. That means if you are in the northern hemisphere, your windows will be facing south, and it you are in the southern hemisphere your windows will face north. If you live in the tropics, you only need to cool your home not heat, so lots of shade and ventilation is required – verandas all round. clever passive solar designs can cool as well as heat from the suns power. There are 2 systems that people confuse when they think of passive solar, 1 is heat caught either in water or air and pumped around this is not passive solar but active solar, 2 is Passive solar is when only natural forces combine to heat or cool, like this passive solar hot water system.
Buildings that use passive solar techniques are usually specially designed to use thermal mass – earth bound homes are a good example of this – large masonry heat sinks or water tanks to collect winter sunlight for warmth. But for cooling use windows that open high up in the building and nearer to the ground to cause a natural draft to ventilate the building letting the hot air out the top, while drawing the cooler air in through the bottom, in a well setup system this air would be drawn from a shady, cool damp environment – like a garden or under a house. The solar or thermal chimney is a grand scale of this principle. There is however an opposite system which uses a combination active/passive where water is pumped through air-conditioning bats surrounding a vertical tunnel – the air flowing through these becomes cooler, cool air drops down into the building from above.
Green houses, like sun-rooms can use passive solar to heat them – the air inside the glass and plastic heat up from the suns energy, but because there is little ventilation the heat can’t get away. No fuel is burned no machines ware out, just panes of glass in the sun to collect energy. Another very efficient solar implement is the solar cooker. I know the first time I heard of a solar cooker, ( ours is a parabola ) My jaw fell open and I thought they must have been joking… If they exist – Why doesn’t every one have one? Free cooking from the sun .. Brilliant! So Any way we made one, and other than being a bit awkward to build and chunky to operate, they are great – certainly saves energy.
Solar cooker, solar furnace or solar forge all use the suns energy concentrated either by mirrors or a parabolic shape focused unto a hot zone this generates enough heat to melt steal, make molten salt and vaporizer water reaching up to 3,000 degrees. Once this much heat is captured it is simple to generate electricity or even store the energy for future use as molten salt or pumping water uphill to be used in turbines later.
Solar radiation – the suns rays – can heat up and increase the temperature of a given area and that is called Solar Gain, without it the earth would be cold and dead – in case you haven’t noticed life on planet earth is already solar powered all living things (with the exception of some life-forms at the bottom of the ocean near magma) are reliant on the sun for energy and warmth. The more powerful and sunny the day the more Solar Gain we get, and this can make cooking in your solar cooker a bit tricky and becomes a bit of an art form – how much wind? what is the ambient temperature? how strong the suns rays? What day length is left?
Passive Solar Is Efficient For Making You Self Sufficient
Passive solar is very efficient and long lasting as there are no moving parts and nothing to wear out, it is also cheaper to setup as nothing is high tech. People who live with passive solar are pleased to not have to light fires for heating or pay the gas or electricity bills. Often a passive solar house is set up with other labor and power saving systems in place, as the designers were very aware of the cost of contemporary homes on the wallet and the environment.
Quite often the homes with passive solar will also have active solar for things like generating electricity, heating and pumping water, and doing other day to day chores. We are very fortunate that the passive and active solar industry has made so many advancements over the years – a lot of it has been by people who have dedicated their lives to walking gently on the earth, and working out ways of doing that without moving back into a cave. It has never been easier or cheaper to install solar technology and the more of us who do it the better for the preservation of the planet.. our great grand children will thank us. Oh! and so will your bank balance when you stop paying for carbon powered energy