All furnaces have a pump that controls the amount of air coming into the furnace. If the furnace pressure is lower than the room’s air pressure then the air will move around the room in such a way that it does not provide a comfortable room air. The way this is done is through a process called “draft”. If there is a large change in the air pressure or temperature that is outside of the house then the pressure outside of the house can change which will cause the furnace to draft more. When the air moves to the inside of the house, it pushes back on the same area causing the same thing to happen. This will force the air to circulate back and forth until the amount of air in the furnace drops to the normal air pressure in the room.
There are also changes in the temperature of the room that can cause drafts to occur. It is also a good idea to keep an eye on the amount of time that a person spends in the room. If the amount of time spent in the room is not increasing then the draft will be moving more air around the room which will create the draft. The temperature of the room will rise as well, which will cause the draft to speed up. A duct that is correctly installed should be able to catch all of these conditions and help to minimize the problems that they create.
There are several different steps that can be taken to ensure that a person’s furnace is working properly. These include: the proper installation of a furnace duct and correctly venting the furnace at all times. Also, an inspection of the furnace gas pressure can be performed once a year and any changes should be noted down. The only way to maintain a quality draft in a furnace is to make sure that it is not overly drafty, nor too drafty.