Development of an electrically-switchable superinsulated glazing shutter for greenhouses in Northern Canada

人们普遍认为，在加拿大北部和偏远社区，粮食不安全是一个日益严重的问题。通过扩大在需要粮食的社区附近的非耕地上建造的温室的使用，粮食供应问题可以得到相当程度的缓解，从而也减少了运输粮食所需的能源。然而，温室通常是以透明结构建造的，可以有效地传递植物生长所需的阳光。由于透明结构不提供太多的隔热，传统温室在大多数气候条件下需要大量的能源来控制温度，而这种能源消耗在寒冷的北方地区是令人望而却步的。开发一种既能维持植物生长所需的条件，又能只消耗少量能源的温室，这一挑战已经被认识到很长时间了，而且还没有得到解决。该项目旨在通过设计和验证一种高性能的超级隔热玻璃百叶窗，在高度隔热状态和高度透光状态之间进行电气切换，从而向实用的北方温室迈出重要的第一步。我们系统的高绝缘特性来自于我们的新型热电池阵列，该阵列由密封的窗板内包含的高度可压缩的充气口袋组成。在展开状态下，面板将具有很高的隔热价值，而在压缩状态下，面板将像传统的透明温室一样，对阳光具有高度的透射性。该系统将能够在两种状态之间快速转换，只需使用静电驱动系统，而不需要任何机械马达部件。这项技术有可能使经济高效、低能耗的温室在加拿大北部变得可行。在这些社区，可行的新型温室产业的好处将产生巨大的健康、经济和社会影响。

Food insecurity is widely identified as a serious and growing problem in northern and remote communities in Canada. The food supply problem could be alleviated to a considerable extent by expanding the use of greenhouses built on non-arable land near the communities where the food is needed, thereby also reducing the energy required to transport the food. However, greenhouses are typically built as transparent structures that efficiently transmit the sunlight required for plant growth. Since transparent structures do not provide much thermal insulation, a traditional greenhouse requires significant energy use for temperature control in most climate conditions, and this energy use is prohibitive in cold northern regions. The challenge to develop a greenhouse that can maintain the conditions required for plant growth while consuming only a small amount of energy has been recognized for a long time, and it has not yet been solved. This project aims to take a first important step toward practical northern greenhouses by designing and validating a high performance superinsulating glazing shutter that can be electrically switched between a highly thermally insulating state and a highly light transmissive state. The high insulation characteristic of our system arises from our novel thermal cell array of highly compressible gas-filled pockets contained within a sealed window panel. In the expanded state the panel will have a high thermal insulation value and in the compressed state the panel will be highly transmissive to sunlight, just like a conventional transparent greenhouse. The system will be able to quickly transition between the two states using only an electrostatic actuation system, without any mechanical motor parts. This technology has the potential to make cost-effective, low-energy greenhouses feasible in northern Canada. The benefits of a viable new greenhouse industry in these communities would have tremendous health, economic and social impacts.