How Plusaire Works
Expressed simply, Plusaire supplies warmed fresh air to your house at a rate equal to or greater than the rate at which your house is using it.
Mechanical ventilation is when a fan is used to draw air into the house. Passive ventilation is the same as opening a window; air is free to enter as its required. Plusaire uses both methods to bring air into the house.
Firstly, air is mechanically drawn into the house by the furnace fan during the heat cycle. This is the time when more oxygen is burnt and exhausted up the chimney than at any other time. Air is also mechanically exhausted by the various fans such as in the bathroom, clothes dryer, central vacuum, and kitchen causing outside air to be drawn into the house through Plusaire. Without an entry point for the replacement air, it would have to find its way in through holes in the house structure or depressurize the house.
Secondly, when the furnace fan is off, fresh air is drawn into the house through Plusaire by the combusting appliances such as a wood stove or fireplace. The air that is being combusted must be replaced and Plusaire does this in the most economical way.
Remember for every cubic foot of air that leaves a house a cubic foot must be brought in to replace it. The diagram shows the method of installation and the air flows.