Repsol YPF

Fortunately, technology continues to progress with the environment in mind. In fact, recently windows with a cold water circuit have been patented which save a lot of the energy required by a building in order to remain cool when the outside temperature is high. 

The inventors are a group of researchers at the School of Aeronautical Engineering at the Madrid Polytechnic University. The windows that they have developed allow you to save 70% on energy which is essential for controlling the air temperature in buildings with glass façades.

The main characteristic of this kind of window lies in the fact that they have a one centimetre thick chamber which contains circulating water. The circuit absorbs the infrared rays so that the sunlight reaches the room but you don’t feel the heat.

In order to prevent the water from heating up and transmitting the heat to the room, the window frame is connected to a geothermal exchanger. This is a system of pipes which transports the liquid to a depth of approximately 20 metres, where the average temperature is usually 15 degrees centigrade. It is necessary to reach this depth in order to transmit the heat to the earth.

The cost of these innovative windows is three times that of double glazing, but its designers claim that the energy saving derived from using them quickly helps to make it a profitable investment.

Heated up by the sun
Windows, as well as being one of the most decorative parts of the house, are the most common entry points for light, provide ventilation and help to receive the heat of the sun in the winter. However, in the summer the air conditioning system sometimes has to work very hard to cool the hot air from heated windows. 

Nowadays, windows not only feature double glazing, some are made from a selective spectral material. This high-performance glass can absorb a high percentage of solar radiation, such that they can reduce the cost of air conditioning by between 10% and 15%. The most efficient windows maintain the inside temperature. In order to achieve this they have special glass and a low-emission covering.

Tips 
Although new and more efficient windows and athermal glass types are becoming more widespread, it is sensible to use curtains, awnings and blinds to keep the inside of the house cool and reduce air conditioning costs. Listed below are some useful tips:

· White curtains and blinds reflect the heat outside the house.

· It is advisable to keep the curtains on south and west-facing windows closed during the day.

· If it is very hot, it is advisable to assess the option of installing awnings at least on south and west-facing windows.

· You can install sheets or reflectors to control the sunlight on south-facing windows in order to prevent the accumulation of heat from the sun.

When you are going to do work on the property it is worth thinking about the possibility of introducing high-performance windows. Despite the fact that it may take years to recover the investment in terms of energy saving, the environmental benefits mean that the decision is worth it. The most commonly used window frames are made of aluminium, wood, vinyl, glass fibre or a combination of some of these materials. Finally the CE label on windows is particularly important given the repercussions it represents.