For example, a fireplace can have such a powerful draft that it can depressurize the entire house and backdraft a furnace in the basement. Downdraft kitchen range exhaust fans are often so powerful that they require a fresh make-up air supply to prevent excessive depressurization. It has been estimated that the majority of all houses can experience enough depressurization on occasion to result in some backdrafting or spillage. An easy way to avoid backdrafting and spillage is to only use electric space heating and water heating systems. Both heat pumps and resistance heaters qualify.
Solar heating is also a healthy choice.
If there are no combustion sources in the house, there will be no combustion by-products in the house. Another alternative is to use sealed combustion appliances. Some of the new high efficiency gas furnaces draw all of their combustion air through a plastic pipe from the outdoors into a totally sealed combustion chamber, then the exhaust gases are directed outdoors with the help of a fan. Water heaters and gas fireplaces are also available with sealed combustion chambers. There are some models that are not sealed, but use induced draft fans that are capable of overcoming any house depressurization and blowing the combustion gases outdoors.