Solar heating and cooling systems: air conditioners with solar energy

Solar thermal uses the sun's heat directly. The solar heating and cooling systems are based on a very simple principle and known for centuries: the sun heats the water contained in a dark vessel. The technologies for the exploitation of solar thermal energy available in the market are efficient and widespread. The fields of application are different from the hot water for domestic space heating in residential and commercial buildings, by conditioning the process of industrial heating and desalination of drinking water.

The heating water for domestic use is without a doubt the most common application at the moment, so much so that in some countries it has become a very common feature in the design of residential buildings.

There are basically two types of technology on the market:

• The vacuum collectors - They have a tubular shape that allows them to capture the rays of only very efficiently. The rounded shape of the tube allows the collector to make the best even when, on cloudy days, the light is diffused and affects the collector from different angles simultaneously.

• Flat-plate collectors - are structures with a glass cover that are installed on the roof. Inside the collectors there are a number of copper tubes. The entire structure is covered with a black material designed to capture the most of the sun's rays. These rays heat a mixture of antifreeze and water that comes down from the collector to the water cooler, usually placed at the bottom of the building.

The rays of the sun, however, can be exploited not only for heating but also for cooling environments. The solar air conditioners in fact use the solar heat to produce cold air or dehumidify it in a similar way as with conventional chillers or dehumidifiers. This application is particularly interesting because the demand for air conditioners increases in those periods where there is more sun. The solar cooling is a reality.

Air conditioners with solar energy

In Italy, almost all air conditioning systems work on electricity, causing the surge in consumption with partial blackouts during periods of intense heat. As a remedy to the energetic advantage of the phantom effect "desertification"? Through the exploitation of solar energy. The technology is relatively dated though little used. Dates back to the 70's patent Japanese Yazaki, a leader in the industry. In Italy, the first plant of this type was actually built in 1980.

How does the system work? Groups are combined refrigerants to heat absorption with solar panels, which heat at low temperature of the water used for the heat exchange.

What are the obstacles to the spread?

Surely the still high cost of absorbers and collectors are not subject to cost-effective economies of scale to get a kW of cooling energy are in fact required 3 square meters of solar panels.

What are the advantages?

Surely a reduction in energy costs, less noise, the ability to be installed outdoors, eco-sustainability, and not least because of the reduced maintenance simplicity of the system.

Pioneers in the industry in addition to the Japanese that the Swedes have in recent days announced the upcoming construction of a factory of solar air conditioners for domestic use with an investment of 15 million Euros for a plant capable of producing 25 thousand units' per year from 2008. The units' cooling can also be aggregated for applications in offices or large buildings. The power of traditional air conditioners varies between 500 kW and 35kW for the most 'small, solar air conditioners instead have a power of 10-15kW, with the possibility' to also produce air and hot water.

 

And in Italy?

Sara 'product in Padua from next September, the first air conditioner running for 98% with energy produced by solar panels. The new device will allow 'to get the maximum cooling of the air in the moments of greatest insolation, that' when this 'more' necessary. The air conditioner will have 'need to just 2% of the electricity consumed by an air conditioner today of equal capacity'. Currently production prospects involve applications in offices, schools and public buildings but within four years of the first models will be available for refrigeration room situations.

Refrigerants

Another alternative environmentally sustainable and energy efficient to cool our hot summers is definitely the use of refrigerant gases, highly popular in Japan to avoid tilt electric urban centers. This technology, in addition to avoid black-out of the system, allows a perfect functioning refrigerant even at high external temperatures (over 45 °).

In Italy, the refrigerant gas occupies a slice of the chiller market of 2%.

 

What are the savings and the actual costs?

In addition to increased energy efficiency, the system allows savings in the bill, with an initial investment much higher than conventional air conditioning systems.

 

26/07/2010

----------------------------------------

Translated via software

----------------------------------------

 

Source:

Italian version of CercaGeometra.it