When looking at two-story homes, one of the ways to optimize comfort, especially when heating or cooling a home, is to zone the first floor from the ground floor. Zoning is usually done at the staircase.

Looking at a typical two-story home layout, the upstairs has all the bedrooms whilst the downstairs will contain the living areas, the kitchen and dining area.

During winter, if warm air comes out of ceiling jet outlets at high velocity (which is done to ensure that the warm air reaches the floor) this creates quite a lot of air movement. The air from the high-velocity ceiling jets can feel cold because of the strong air movement, despite being heated.

It also creates currents of air around the home because of the rapid displacement of air from the jets.

As any science student will tell you, warm air rises. In a two-storey home, that warm air will rise via the stairs as the line of least. In summer, when trying to cool the upper storey so you can sleep, the cool air will go down the staircase to the lower storey and is replaced by the warmer air it displaces.

One effective way of combatting this issue is zoning the house to limit the escape of cool or warm air from the area of the house you are trying to optimize, for example through a heavy drape covering the stairway. This will block off the pathway of the airflow, making it quicker and easier to heat or cool the area of your choice.