Facilitator manual: How to use the chimney solar dryer


This manual was first designed to guide the facilitation of training workshops on how to use the chimney solar dryer in Dadeldhura, Nepal. The information has been generalized and can be modified to lead trainings with the chimney solar dryer anywhere in the world. This training agenda assumes that the chimney solar dryer has already been built.

The manual includes a full list of materials needed for the training (page 8), as well as best practices for engaging learners and principles of adult learning, including classroom assessment techniques (CATs) and active learning strategies. For evaluation purposes, the manual also includes pre- and post-training assessment questions, which can be administered as a survey or group discussion. Several visual training aids can be found as appendices.

Overview of the facilitator manual: Training objectives and learning activities

The overall purpose of these learning activities is to help give farmers and other community members the knowledge and confidence to use the chimney solar dryer to dry fruits and vegetables. This training will cover the benefits and nutrition of dried fruits and vegetables, how to select and prepare fruits and vegetables for drying, and how the chimney dryer works, including setting it up and loading it with produce. In addition to drying, the training activities will explore safe storage and consumption of dried foods.

In addressing each of these issues, farmers reach a more complete understanding of how to properly dry food using the chimney dryer and how to safely store fruits and vegetables, extending shelf life and making these nutritious foods available during the lean season. The topic also encourages them to diversify their diets and consider new uses for dried foods. To achieve this purpose, you — the facilitator — present this training.

By the end of this training, participants will have accomplished the following activities:

  • Reviewed how the chimney dryer works, the set-up process, and its benefit
  • Understood critical concepts key to drying: solar radiation, air speed, temperature, and water-loss
  • Followed proper sanitation and personal hygiene when handling the fresh produce and using the chimney dryer
  • Prepared a variety of fresh produce items to dry in the chimney dryer
  • Loaded the dryer with produce items and rotated the trays for more uniform drying
  • Understood the health hazards of insufficiently dried product and determined if product is dry enough to safely store
  • Experimented with different airtight and sanitary storage containers and conditions
  • Understood the nutritional benefits of dried produce and any changes in nutrition that are a result of drying
  • Tasted dried product and discussed/brainstormed different culinary uses, recipes, and market opportunities for dried products
  • Created a community plan for utilizing the chimney dryer moving forward

Scheduling the training

For this training, please follow the activities in the order recommended, especially preparing the dried product and placing it in the dryer early in the day so it has adequate time to dry. To prevent moisture development and reduce health hazards, we recommend that you bring the drying food product inside overnight.

The sessions total about 10 hours of active learning time, but can be broken up into multiple (ideally two) days. We recommend starting this training the day after building the dryer and conducting it over two consecutive days, in which case, day 1 should end after learning session #9 “Weather, temperature, and drying time” (which is around six hours of learning time, not including breaks or lunch) and day 2 (about four hours long) should begin with learning session #10 “Measuring dryness of product”. If you do not have a full two days for this workshop, you can shorten the training several ways, which are discussed on page 6 of the manual.

To build upon and reinforce the training content, we encourage you to bring successfully dried fruits and vegetables to the training for demonstration and tasting purposes. For instance, the use of dried foods throughout the day during snack breaks or rehydrated in lunch dishes can help emphasize the learning.

Value Chain

Postharvest practices