90% Furnace venting. Posted on August 22, 2012 by Andy. With these higher efficiency furnaces, came some other considerations. The 90% implies that 90% of the heat that is put into the furnace is transferred into the duct system and subsequently into the homes living space leaving only 10% going out the exhaust.
The definition of a direct primary election is when people vote for candidates of their political party by direct vote instead of by delegates at a convention.
Diffen âº Politics âº U.S. Politics. The electoral process to nominate a candidate for a presidential election is usually called the primaries, but there are two different systems that states use: caucus and primary.tates choose whether they want to hold primaries or caucuses. Most states hold primaries but states like Iowa, Louisiana, Minnesota and Maine use the caucus system.