What is a Chinese Greenhouse?
The short answer to this question is that a Chinese greenhouse is a passive solar greenhouse designed to allow us to grow warm-weather vegetables during the off-season using only solar energy.
The longer answer is that a Chinese greenhouse is a passive solar greenhouse designed much like a passive solar home in ways that allow it to capture as much of the low-angled winter sun as possible. The long axis of the greenhouse runs east and west, also like a passive solar home. Moreover, there’s no glass or plastic on the north-facing roof, which would lose an enormous amount of heat during cold winter days and nights.
Chinese greenhouses are also pretty airtight and very well insulated – again like passive solar homes -- so that the solar heat they gain during the day isn’t lost at night. Like a well-designed passive solar home, these greenhouses are built with an abundance of thermal mass—solid material like adobe or concrete – that absorbs heat during the day and releases it at night, helping to maintain suitable temperatures even on the coldest of winter Nights.
Well-built Chinese greenhouses are also typically earth-sheltered, tucked into a hillside or bermed. This helps maintain warmer temperatures in the winter and cooler temperatures in the summer.
How are they different/better than conventional greenhouses? What makes them so special?
They are the only affordable way to grow warm-weather vegetables in colder climates. They are more expensive to build but a whole lot less expensive to operate than a conventional greenhouse, which is one of the most energy-inefficient structures humans have ever devised.
Here’s a chart that will help you understand the key differences:
|Conventional Dutch Style Greenhouse
Ideal for growing warm- weather and cool-weather plants year-round, especially in the late fall, winter, and early spring
Not suitable for growing warm weather vegetables in the off-season without costly inputs of energy to heat them
Heated and cooled naturally although some fans are typically required
Heating and cooling require enormous amounts of fossil fuel energy
Long axis runs east and west, providing maximum surface for solar gain in the winter
Long axis typically runs north and south, greatly reducing the surface area available for solar gain in the winter
North roof and east and west walls and glazing are very well insulated to ensure optimal temperatures for growing all winter long
Virtually no insulation, though some growers may cover the glass or plastic with an insulation blanket during the winter when attempting to grow in a conventional greenhouse
High-density materials like concrete floors and walls that absorb solar heat during the day and release it at night, thus helping to maintain suitable daytime and nighttime temperatures during the colder months of the year
None usually included so temperatures range widely from exceedingly hot on sunny winter days to bitterly cold at night
Usually earth-sheltered (built into a hillside or bermed) to help maintain a more uniform temperatures during the year; this is especially helpful in winter months
None, so they are vulnerable to environmental temperature variations
How long have they been around?
The Chinese started building these greenhouses in the 1980s and have recently greatly expanded their greenhouse operations because of early successes.
Are they difficult and expensive to build?
Chinese greenhouses are more difficult and more costly to build than conventional greenhouses, but they are a whole different breed of animal. They are insulated and airtight, contain thermal mass to regulate heat, designed to capture the low-angled winter sun for heat, earth-sheltered, and more. All this means you are building a much better structure, one that’s much more conducive to growing through the dead of winter using only solar energy, so it will be more challenging to build and more costly than a conventional greenhouse.
Do they really work?
Amazingly well…The Chinese have had great success. I am still learning how to grow in mine, control moisture levels, maintain cooler temperatures in the summer, and control insects, but I have had great success so far. I have been able to harvest tomatoes and peppers as late as February. I harvest leafy greens and herbs all year round. I am even starting to grow root vegetables over the winter, like beets.
Does your book contain all the information I’ll need to design and build one?
In my new book, cleverly titled The Chinese Greenhouse (that took some thinking), I explain how to design and build one of these unique structures, including what materials you can use and how you can do so affordably. The last chapter is a photographic documentary of the construction of my greenhouse to help readers understand the process.
In the book, I also describe ways to store surplus heat generated on cold but sunny winter days and make it available at night. Furthermore, I explore ways growers like you can store surplus summer heat for use many months later in the dead of winter. (These are called short-term and long-term heat banking, respectively.)
Winning Giveaway Question
Winning Question from jamiesolorio on Instagram
Why choose to build a Chinese greenhouse over the standard greenhouse? Thank you.
Chinese greenhouses are designed to allow you to grow warm-weather vegetables like tomatoes, cucumbers, and peppers as well as cold-footed vegetables like kale and lettuce throughout the winter using only solar energy and maybe a little supplemental lighting. You can't do this in a conventional greenhouse without exorbitant energy bills to heat it during the winter months.
Dan Chiras, Ph.D, is the author of numerous books on renewable energy, including The Solar House and The Homeowners Guide to Renewable Energy. He has been growing in greenhouses for nearly two decades and in his own passive solar Chinese greenhouse since 2017. Dan lives in Gerald, MO.