My natural gas furnace and hot water heater are currently in my basement, that I am working on finishing. Right now they draw in combustion air from inside the basement and exhaust air through horizontal vents out of the back of the house. I want to frame the furnace and hot water heater inside of a utility room that is around 8'x8'.
1) Do I need to run pipes to bring in combustion air from the outside?
2) What size vents? They are both forced air vents. The furnace has a 2" PVC elbow stubbeed out for combustion air. The water heater has a 3" intake. They are both about 12' to 14' from the outside wall.
3) If I do need to run vents, are there regulations on how close the intake can be to the exhaust?
4) Would it be sufficient to just put some vents in the wall of the utility room, so that the furnace and water heater can draw air from the rest of the basement?
5) This is not really related but... Where can I find a good resource for sizing air ducts and air returns for my basement. The house is a two story with a full basement. There are about 700 sq ft per floor, w/ 8 ft cielings. I also plan to add a fireplace to the basement.