The new non-electric air conditioning units actually use heat to make the cool air.Electric powered air-conditioning relys on Fossil fuel to electricity at the power plant and then electricity to mechanical power at the compressor.
新式非电空调利用热能来制造冷空气，而传统空调需要依靠电力和燃料。
上文中的non-electronic air-conditioning就是指非电空调技术，世博园中使用的就是non-electronic air-conditioner。除此之外，环保类型的空调还有solar air-conditioner：Solar air conditioning refers to any air conditioning (cooling) system that uses solar power.
在炎热的夏天，除了使用空调，还有其他的方法可以减少热量，比如这种passive solar cooling：
Passive solar building design aims at slowing the rate of heat transfer into a building in the summer, and improving the removal of unwanted heat.
被动式太阳能建筑的设计能减少夏天进入房间的热量，同时增快热量的散播，用这种方式让房间凉快下来。
另外一种Earth cooling tubes，地温空调，也可以用来帮助散热，通过利用地下土壤的储热储冷能力，在夏季可以把地下的冷量转移到建筑物之内，这种也被称为geothermal cooling
