Radiative Sky Cooling: What is it & Why does it affect your AC costs?

Standard Air Conditioning

It is difficult to remember our lives without air conditioning, especially during those hot summer days. And in case you’ve ever wondered about the magic that runs these devices, here is a quick breakdown.

Conventional air conditioners use a liquid called refrigerant to cool down the air in the room. The liquid circulates from the inside to the outside unit, but there’s a neat twist – the refrigerant turns into a warmer gas, and when it is cooled, it turns back into a liquid state. You do not have to be a scientist to put two and two together and figure out that this process requires energy. Sure, it is great to be able to enjoy summers without being sweaty all the time, but once that electricity bill arrives… Oh, boy!

Wouldn’t it be great to cool down your house while keeping the electricity costs down? Perhaps radiative sky cooling is the solution to this problem.

What is Radiative Sky Cooling?

If you paid attention in physics, you should know that the temperature in Space goes below -200°C. On the other hand, it can also get very hot – up to 150°C outside The International Space Station when it is facing the Sun. The reason why the temperature in the Space oscillates so much is that there is nothing to regulate it. On Earth, we have an atmosphere that works like the huge air conditioner keeping the temperature between -50°C and 50°C.

People have already managed to harness the heat of the sun by using solar panels to heat up the water and convert the power into electricity. BUT, is it possible to harness the coolness of space even on a hot sunny day?

How Can Radiative Sky Cooling Help Me Lower the Temperature in My Home?

Stanford professor Shanhui Fan and his team of electrical engineers are working on developing a system that will harness radiative sky cooling and use it to cool down the temperature in buildings and homes.

The whole system is based on panels placed on the roof. Their surface is covered with an optical film that absorbs the radiative sky cooling and reflects the heat of the Sun. The panels are “vascularized” with tubes with circulating water. This way, the liquid gets colder than air temperature and goes back into the building/house and cools down the air in the room. When the water heats up, it goes back on the roof, transfers the heat to the panel which emits it into space. The cycle then repeats.

This cooling method does not require input energy whatsoever. It is completely based on the energy exchange with the sky.

The team has founded a company called SkyCool Systems, whose plans include integration of their revolutionary system into commercial air conditioning and refrigerating industry. Also, they see an opportunity in helping data centers cool their server rooms.

Can New Cooling Technology Help Us Save Money?

Needless to say, the system almost does not require electricity which is a huge plus. It is estimated that this revolutionary way of air conditioning could save between 20% and 50% of energy on a daily basis, which could significantly reduce our monthly electricity bill. All we have to do is wait for the mass production to start. Also, we can assume that the installation of the system will not be cheap, but according to the research results, it will be an investment that will quickly pay off.

The Bottom Line         

Using the energy of the wind, water, or Sun is something we are already familiar with. But is it possible to harness the coolness of the space? The answer to this question is no longer a mystery thanks to Stanford professor Shanhui Fan and his team of electrical engineers. They have managed to design panels covered with a special film that can reflect more than 95% of Sun’s heat, and absorb radiative sky cooling. The system managed to cool down the building in Las Vegas and reduce the energy needed for the cooling between 20% and 50%.

Other significant advantages of this air conditioning method are that it uses renewable energy source, and it is eco-friendly. This might seem surreal, but it is happening people! The future – is now!