Solar Air conditioning

With high summer temperatures, air-conditioning and thermal comfort are increasingly important issues, but raise the challenges of high energy consumption and of environmental consequences. Three recent projects use solar energy to operate air-conditioning systems: - The Californian-based company SolCool is to launch a hybrid solar powered air conditioner, SolCool Millennia version 4, which runs on solar panels, from a wall socket or batteries that can run 12-24 hours in the case of power cuts and insufficient sunlight. The panels use small photovoltaic (PV) solar cells to power the 5.3 kW air-conditioning system. Version 4 can also provide heating and has attachments for purifying water, and running lighting or ceiling fans. It addresses the fact that peak demand for cooling is during the day and the installation of solar panels on a roof costs 20 000-40 000 USD before subsidies, a price which might be discouraging to consumers but is likely to be cost-effective in the longer run. According to SolCool, this system's energy efficiency rating (EER) equals 30. To give a clearer idea of what this means, bear in mind that the US Department of Energy's federal Energy Star rating standard is granted to air conditioners with an EER of 9.7. - Givaudan, a French perfume manufacturer, has decided to use a system combining solar panels with a powerful insulation system for its 5000 m² head office near Paris: 300 m² of solar roof panels in vacuum tubes produce temperatures of 72°C that operate a 110 kW lithium bromide absorption plant. A secondary fluid consisting in chilled water flows within the ventilation system. Insulation is provided by glass walls within an airtight outer glass casing. Givaudan expects the payback period to be 12 years. - Haribo's museum goes solar Haribo's sweets museum in Uzès near Nîmes in the South of France is now using solar cooling. The number of visitors is on the rise and a new building has been added to the museum to cope with the influx: an additional area of 1113 m² on two floors, 829 m² of which are heated and cooled - that is a volume of 2486 m3. The solar a/c installation called Suniverse is based on 28 flat collectors with a surface of about 50m² and an absorption unit with a nominal cooling capacity of 10 kW. Furthermore, 14°C cold ground water is available throughout year when the cooling capacity of the absorption unit is not sufficient (e.g. on hot summer days). Warm water is also produced using the solar installations and completed by 35-45°C waste water from the production process.,