Now let's look at the disadvantages: 1  You don't know where the makeup air is coming from. 2  Contaminants from an attached garage or moldy crawl space can be pulled into the house. 3  Ventilation air probably won't be mixed or distributed well. 4  The only filtration that happens is through the building enclosure.
The Qing Dynasty (1644â1912) was the last Chinese dynasty, and the longest dynasty ruled by foreigners (Manchus from Manchuria, northeast of the Great Wall).
Under the Qing the territory of the empire grew to treble its size under the preceding Ming dynasty (1368â1644), the population grew from some 150 million to 450 million, many of the non-Chinese minorities within the empire were Sinicized, and an integrated national economy was established.