A fresh air kit is any kind of kit that is used to get some kind of fresh air in a otherwise difficult to reach place. There are fresh air kits for firemen in fires, but also for cars to tune engines to work better. There are also fresh air kits for in-home usage.
This is installed on cars, typically sports cars, that allow fresh air to be delivered directly to the engine to improve horsepower, and possibly boost fuel economy as well; although the latter is not proven.
This kit is meant to connect to the return side of a central furnace to control the outside air supply.It makes the furnace more efficient especially in poorly vented basements.
This is a carbon crystal packet that you get at the home improvement stores. This take the odor out of moist place and replaces it with a fresh smell. Usually used in basements, or any place where moisture tends to accumulate.
Fresh air kit is a must in a congested place where pure air is not available in plenty. This helps to circulate the air in a place where old methods of heating is done with less possiblity for impure air to vent. This is easy to install and operate.