Static pressure is the force that moves air through
the duct system. It is measured in water column
inches. Total pressure is velocity pressure + static
pressure. To understand static pressure suppose
the air handler fan pushes air into the duct system.
When the air fills the space it creates pressure and
the pressure forces the air out through the branch
ducts and then through openings (supply
registers). The air moving out of the registers is
the velocity pressure and the pressure remaining is
the static pressure.
You have a 30’LX20’WX10’H room. The room already has a 30,000 BTU natural gas water heater in it pulling combustion air from the room. What is the largest BTU high efficiency natural gas furnace you can install in this room before the room is considered a confined space?
[FONT=Calibri]a) [/FONT]120,000 BTU
[FONT=Calibri]b) [/FONT]90,000 BTU
[FONT=Calibri]c) [/FONT]60,000 BTU
[FONT=Calibri]d) [/FONT]None of the above.