Air-tightness is a spectrum - a reasonably tight house still leaks enough to make up most ventilation needs introduced by an exhaust only ventilation system.
Very tight homes may need air inlets (literally fancy holes in the wall somewhere), or a balanced ventilator system. Appliances that can draft are also an issue. Some are generally discouraged, like drafting water heaters, and some will require their own air inlet, like wood burning fireplaces.
Very tight homes may need air inlets (literally fancy holes in the wall somewhere), or a balanced ventilator system. Appliances that can draft are also an issue. Some are generally discouraged, like drafting water heaters, and some will require their own air inlet, like wood burning fireplaces.
"2011 Ventilation Guide" by Armin Rudd is a very readable introduction to this subject. https://buildingscience.com/bookstore/books/2011-ventilation...
For online reading, here is a very short introduction: http://www.greenbuildingadvisor.com/green-basics/ventilation...
Here is a longer discussion: http://www.greenbuildingadvisor.com/blogs/dept/musings/desig...