51.   Stick-stacking is piling boards on one another with one-inch sticks between layers to allow air to circulate properly.

52.   The air quality in your home is dependent upon the strength of pollution sources, how well you clean and how much fresh air circulates through the house.

53.   The excited chatter of reunited cousins and great-aunts fills what little air circulates in the low-slung building.

54.   The fire will need oxygen as it burns so keep the newspaper and kindling layers loose so air can circulate.

55.   The idea here is to allow air to circulate freely over every surface of the wood.

56.   The second most important measure is to allow more air to circulate within the home by opening windows or doors.

57.   The purpose of the sticks is to allow air to circulate all around the boards.

58.   The tent had no windows, meaning almost no air circulated inside.

59.   The weepholes are designed to allow air to circulate between main window and storm, and equally important, for water to drain out.

60.   They are built off the ground so air can circulate underneath.