Video: Using the chimney solar dryer


This 3-minute video shares steps and advice for using the chimney solar dryer. The video is broken down into five chapters.

  1. Preparing fruits and vegetables — Start with clean, undamaged produce. If produce is thinner or is peeled/pitted it will dry faster. 
  2. Loading the product on the trays — Trays should be loaded with a single layer of produce.
  3. Putting the trays in the dryer — Leave the first tray position open so that the air can warm before moving over the fruits and vegetables. Trays can be stacked two high.
  4. Rotate the trays while drying — For more uniform drying, rotate the trays 2-3 times per drying cycle.
  5. Time of day and weather issues — If produce takes multiple days to dry, remove trays and store in a dry place overnight.

This video part of a series of short videos about how to build and use the chimney solar dryer, designed by UC Davis researchers. Closed captioning is available on the video and a transcript is provided below.


How to dry fruits and vegetables with the chimney solar dryer (video transcript)
Researchers at UC Davis designed a solar dryer for small-scale farming systems around the world. 

This video explains the basics of drying fruits and vegetables using the chimney solar dryer and is third of three videos about this dryer. More information is available in the manual on our website.

Preparing fruits and vegetables for drying. Make sure you start with undamaged, clean product.

Small, thing items like leafy green vegetables and herbs may dry in a few hours, while larger, bulkier products like tomatoes or mangoes will take a few days to dry. You can dry larger fruits more quickly if you remove pits, peel the product or cut into thin pieces.

Loading the product onto trays. Arrange the product on mesh trays to dry. Trays should be loaded with a single layer of product, but the fruits and vegetables will shrink when they dry, so you can overlap slightly.

Putting the trays in the dryer. When placing the trays, leave the first tray position open, farthest from the chimney. This helps the air warm before moving over the fruits and vegetables. 

You can stack the trays two-high as long as the product doesn't touch the tray above it. Make sure that the plastic cover doesn't touch the product, which will slow airflow. You will want only a few centimeters of headspace above the fruit and below the plastic covering to ensure air flow.

Secure the plastic cover and make sure that the airflow entrance and chimney exit are not blocked, so that air can flow only in one direction.

Rotate the trays while drying. The temperatures and humidity varies in different parts of the drying table, so rotate the trays two or three times per drying cycle for more uniform drying.

Time of day and weather issues. Air temperature, humidity, and weather can affect drying time. Some product will take multiple days to completely dry. If so, remove the trays with product and store in a dry place, then replace them the next morning. 

The chimney solar dryer works on sunny and cloudy days. However, it does not work during extended periods of rain or heavy clouds.

After proper drying, vegetables should be brittle and snap or break, however, fruits may be pliable and flexible.



Value Chain

Postharvest practices


Chimney solar dryer