Solar Dryer and Solar Air Heater





Thai  Solar Power

Solar Energy Consulting

Tel: +66 8148 16679





The advantage of solar drying systems is low operation costs combined with high product quality.

A solar dryer avoids problems of other drying technologies such as high energy consumption, complex technology (maintenance costs), contamination and pollution problems.
Solar dryers are used in the agricultural and industrial sector:

Industrial Sector

The goal of industrial solar technology is to save costs by reducing electricity and fossil fuel consumption. In most applications the solar air collector is used to heat or pre-heat air for drying or humidification applications. Processes, where solar drying technology can be used include various industrial sectors. Such as: Wood drying, Ceramic and Mosaic drying, tire & rubber manufacturing, textile drying, metal finishing, pharmaceuticals, tobacco humidification, food production etc...


Agricultural Sector

Drying is an important post-harvesting process for various fruits and spices such as:

Dried herbs & spices (chili, pepper, tea, coffee, mint, basil,...)

Dried fruits (banana, pineapple, apple, kiwi, mango, coconut)

Dried vegetables (tomatoes, carrot, onion, corn, mushroom, peas)

Dried meat (fish, squid, pork,...)

Dried wood, rattan

Drying agricultural products is not only aimed at food preservation but also at modification of tastes and textures of the products. The drying process increases the market value of the product. In most cases the market value of solar dried products is even higher because the product helps to protect the environment by using renewable energy. The product becomes an environmentally friendly product and can be advertised in particular (green labeling). This can open new markets especially for export.
Sometimes fruit and spices drying is achieved by spreading products on beaten earth or mats directly exposed to solar radiation and weather conditions. This method is susceptible to problems caused by insects, rainfalls, animals and dust. Examples are fly infestation on bananas, fish etc. In the special designed solar dryers (such as tunnel or greenhouse dryer), the product is protected from unwanted impacts and therefore increase the product quality significantly.



1. Solar tunnel dryer

Solar Tunnel Dryer

In 2005 solar tunnel dryer has been deployed to 14 location in the north of Thailand. Currently, five more systems are demonstrated in many parts of the country.


2. Greenhouse dryer

Solar Greenhouse Dryer

The solar greenhouse dryer is now used in 8 locations in Thailand. In 2008, more than six greenhouse dryers will be installed.


3. Roof integrated solar air heater

Roof integrated Solar Dryer

The roof integrated solar air heater has been installed in Suan Pueng Thailand and is until now used commercially to dry bananas. In 2007 a new system has been installed in Laos PDR


4.Solar Wood dryer

Solar Wood dryer

Solar wood drying systems for timber and rattan are in operation and new wood dryer types are under development.

More to read:

Investigation of solar roof collectors for preheating of Air at drying facilities in northern Thailand 



Read more about solar drying

Solar drying in Thailand: Unwanted technology?




Solar drying systems must be properly designed in order to meet particular drying requirements of specific products and to give satisfactory performance. Designers have to investigate the basic parameters such as dimensions, temperature, relative humidity, airflow rate and the characteristics of products to be dried. The simulation of solar drying is essential to optimize the parameters of solar drying systems. The Solar Dryer uses simulation tools which allow to design the system in a professional way (more about simulation). By using the simulation tools, it can be assured that the dryer achieves the required performance and that the system is most economical.  

We have the equipment and experience to measure properties of the drier and the product (such as dry mass, moister content, radiation, specific heat, air-velocity, etc..).


Finance solar dryer projects in Thailand

Currently, there is no subsidy for solar dryer in Thailand. However, there are soft loans available from the following banks which participate in the Government Revolving Loan Fund.








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