Low cost, robust Solar Air Heating - hc-solar

Dr.-Ing. Christoph Müller
52062 Aachen-Germany
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The concept of space heating using solar air heaters is already known and proven for many decades. This redesigned concept helps to spread the idea due to its low cost and modular character, which allows to implement systems of any size. The solar air heater is usually placed on the roof in combination with a rock bed storage below the floor of the heated room. The big thermal capacity of the storage can keep heat for several days even without sun. Using local material makes the key components cost effective and accessible to clients. Typically pay back is reached already after 3 years by saving conventional fuels. Another important fact is, that we train local craftmen to plan and realize projects independently. Very little maintenance is required for the systems, which improves sustainability.

This concept has been developed and proven in the framework of research projects (BMBF, Solar-Institut-Jülich, AiF) and technical cooperation (IKI, BMZ, Ecoandina, Solarglobal) under the extreme climate in high mountain regions like the Argentinean Altiplano, Bolivia and the Himalaya in Ladakh and Kargil during the past 20 years.

All materials used are available locally permitting to realize effective systems at lowest cost, creating local labour. It is a very reliable system as it uses air as heat transfer medium - it never freezes or overheats and leakages have no significant impact. Our installations have been in continuous operation on the Argentinan Altiplano at an altitude of 3800m since 1997.

The simplest and most economical concept is to heat air and blow it directly into the room with help of a PV powered fan. Though the room is not heated at night, this concept has been implemented with great success in schools, kindergartens and offices, which are used only during daytime.

The more advanced system with storage circulates the warm air from the solar air heater through the rock bed below the floor in a closed loop. The floor acts as under floor heating, delivering an ideal temperature distribution profile in the room. Due to the big thermal capacity of the storage, the rooms are heated 24h per day, even during 1-2 days without sun. No more need to care about your space heating.

Optionally the system can be combined with hot water preparation. For this purpose a heat exchanger is placed inside the chimney, which transfers heat to the water. The water then circulates by natural  convection to an insulated water tank inside the house.

Over 27 class rooms are equipped with the heating system on the Argentinian Altiplano, avoiding monthly fire wood transports from the low land.

More than 12 private houses in Ladakh have proven the concept in the harsh Himalayan region at -15°C. The owners have removed their traditional Bukhari ovens, as the solar heating keeps the room warm over 24h, something they never experienced before: no more need to search for fire wood or buy gas, no more smoke in the rooms which causes respiratory diseases, no more carbon monoxide accidents. During the 6-7 month heating season 2,5 tons of CO2 emissions are avoided per household while improving living comfort.

It would be a pleasure for us to design a solar space heating system for your needs.
Get in contact with us.
Copyright Dr.-Ing. Christoph Mueller, chris@hc-solar.de - All Rights Reserved
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