Ultra Boiler Manual
Part number 550-100-440/0122
84
ANSI Z223.1 denes unusually tight construction where:
1. Walls and ceilings exposed to the outside atmosphere have
a continuous water vapor retarder with a rating of 1 perm
or less with openings gasketed, and . . .
2. Weather-stripping has been added on openable windows
and doors, and . . .
3. Caulking or sealants are applied to areas such as joints
around windows and door frames, between sole plates and
oors, between wall-ceiling joints, between wall panels, at
penetrations for plumbing, electrical, and gas lines, and in
other openings.
For buildings with such construction, provide air openings into
the building from outside, sized per the appropriate case in Fig-
ure96,page85 if appliances are to use inside air for combustion
and ventilation.
e appliance space must never be under a negative pressure
unless all appliances are installed as direct vent. Always provide
air openings sized not only to the dimensions required for the
ring rate of all appliances, but also to handle the air move-
ment rate of the exhaust fans or air movers using air from the
building or space.
If the air openings are tted with motorized dampers, electrically
interlock the damper to:
y Prevent the boiler from ring if the damper is not fully open.
y Shut the boiler down should the damper close during boiler
operation.
To accomplish this interlock, wire an
isolated contact (proving
the damper open) in series with the thermostat input to the
boiler. e boiler will not start if this contact is open, and will
shut down should it open during operation.
e Ultra boiler can use inside air if no contaminants are pres-
ent in the boiler space. (If contaminants are likely to be present,
install the boiler as a direct vent appliance, using the appropriate
vent instructions in this manual.)
e boiler room must be tted with combustion air openings large
enough to provide air for all appliances in the room. Use the fol-
lowing information to size the openings. Ensure the installation
complies with all applicable codes and standards.
Air openings provide for ventilation (as well as combustion air)
to prevent overheating of the boiler controls and boiler space.
Air is also needed for other appliances located in the same space.
Use Figure96,page85, selecting the appropriate installation
conditions.
Air openings must be sized to handle all appliances
and air movers (exhaust fans, etc.) using the air
supply.
e sizing given in Figure96,page85 is based on the National
Fuel Gas Code, ANSI Z223.1, allowing adequate air openings
for gravity-vented gas appliances (Category I) in addition to that
needed for the Ultra boiler.
e air openings recommended in Figure96,page85 will allow
adequate ventilation and combustion air provided the boiler room
is not subjected to negative pressure due to exhaust fans or other
mechanical ventilation devices.
Refer to the National Fuel Gas Code for dealing with other
conditions.
e free area of openings means the area aer reduction for any
installed louvers or grilles
. Be sure to consider this reduction when
sizing the air openings.