Ground Source Heat Pumps (part 1)
Posted on 5th February 2020 at 15:45
Ground Source Heat Pumps (part 1)
We’re gradually becoming more energy and environmentally conscious and consequently, we recognise that we have to do more to protect the world around us (and our pockets). Burning fossil fuels is no longer as sustainable as we once thought and whilst we are starting to realise the benefits of solar and wind power, the initial investment in infrastructure required to make these viable on a mass scale, is not yet in place. But what are the alternatives? Here, we consider Ground Source Heat Pumps, how they work and the benefits to installing them in your home or development.
Like solar panels, these devices take their energy from the sun, but do so in a slightly different way. Heat is able to travel in three distinct ways; conduction, convection and radiation. The sun’s energy comes to us via radiation across the void of space and falls onto the ground, heating it. In fact, it heats the ground considerably, generating around 600 watts per square metre over an 8-hour period (the average amount of time that the sun shines around the globe), which equates to 4.8 kilowatt hours per square metre. That is not inconsiderable, and what’s more, this energy warms the earth to a depth of around 2 metres, and that’s a collectable resource.
Ground Source Heat Pumps are a great way to tap into a pool of energy that would otherwise not be used. The apparatus consists of a loop of pipe – usually called a ground loop – which is placed underground in your garden. A mixture of water and anti-freeze is circulated through the tube via a pump, absorbing this energy from the ground and passing it through a heat exchanger which collects it and uses it to heat your home. In line with the second law of thermodynamics, as the heat is taken from an area, energy from the surroundings moves in to warm the area up again, giving you an almost endless supply of heat.
The longer the loop used, the more energy that it is capable of absorbing, so a bigger garden gives you a greater harvest, but if space is constrained, the bore can be placed vertically so a small pipe goes deeper into the earth to give the same effect. In a normal installation, the trench is usually 3mm wide by 2 metres deep and may extend 40 to 60 metres in length around a non-linear path so that the piping can take the maximum amount of heat from the earth and deliver it to the system.
If you’re considering eco-friendly alternatives to heat your home or new development, get in touch with Kent Building Developments today!
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