Sweating Buildings, a new concept (research) for energy saving

A research from a group of engineers, in the Swiss Federal Institute of Technology in Zurich, suggested that may be we will be able in the near future to do without air conditioners and use in its place, for the purpose of cooling down, polymer mats with the roofs that causes the building to sweat.

 

It’s said that these mats will be a simple and convenient solution for cooling down buildings in heat of summer.

 

A temperature responsive polymer was used (PNIPAM) to mimic the biological process of sweating, this polymer is covered in another temperature responsive hydrogels creating a water absorptive membrane which can trap the rainwater.

 

The normal mats would act like sponges reacting to the rain water, but the PNIPAM mat will have additional benefit. When the sun heat reaches 32°C or more the mat starts to shrink releasing the trapped water to the surface, and imitating the process of biological sweating. Later on the mat “absorbs the heat from the building causing the water to turn into vapor, causing the building surface to cool down by 15°C.

 

The concept looks like to be promising, but currently it was only applied on a very limited scale. As the team used 5mm mats in thickness and fixed them on the top of model railway building and using a lamp, the sun-heat was imitated.

 

It was noticed that using the PNIPAM mats the building gained heat much slower than the uninsulated buildings, as stated by Alien Rotezetter the leading author of the research. And according to the researchers, 60% of energy that was previously used by air conditioners, now can be saved.

 

So, till this moment the cooling system doesn’t substitute for the air conditioning system, but rather act as a complementary system to save energy. Besides the day should be warm enough “over 30°C “for the system to work effectively. If it was not, then the system would not simply work.

 

Add to that there are some issues that need to be addressed like if the temperature became freezing will the trapped water turn into ice and harm the PNIPAM mat? Or can it be made resistant to freezing temperature?

 

Curiously, Rotzetter stated that she and her team rather than looking for financial benefit from their research, they aim for be people to benefit from it on a large scale.