Crown Boiler TWZ Series, Installation Instructions Manual

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9
Air for Combustion and Ventilation
Sufficient fresh air must be supplied for combustion and ventilation. Provisions for combustion and ventilation air for oil
burning equipment must be made in accordance with Section 1.5, Air for Combustion and Ventilation, in the latest edition of
Installation of Oil Burning Equipment (ANSI/NFPA 31).
To ensure an adequate supply of air for combustion, ventilation and flue gas dilution, start by determining whether the
boiler is to be installed in a building of unusually tight construction. A building of unusually tight construction can be defined
as one having the following features:
•
Walls and ceilings exposed to outside atmosphere have a continuous water vapor retarder with a rating of 1 perm or
less with openings gasketed and sealed
•
Weather stripping has been added on openable windows and doors
•
Caulking and sealants are applied to areas such as joints around window and door frames, between sole plates and
floors, between wall-ceiling joints, between wall panels, at penetrations for plumbing, electrical, and gas lines, and
at other openings.
For Buildings of Other than Unusually Tight Construction
1) Determine whether the boiler is to be installed in a confined space - A confined space is defined as having a volume less
than 50 cubic feet per 1000 BTU/hr input of all appliances installed in that space. To determine whether the boiler room is a
confined space:
a. Total the input of all appliances in the boiler room in thousands of BTU/hr. Round the result to the next highest
1000 BTU/hr.
b. Find the volume of the room in cubic feet. The volume of the room in cubic feet is:
Length (ft) x width (ft) x ceiling height (ft)
In calculating the volume of the boiler room, consider the volume of adjoining spaces only if no doors are installed
between them. If doors are installed between the boiler room and an adjoining space, do not consider the volume of
the adjoining space, even if the door is normally left open.
c. Divide the volume of the boiler room by the input in thousands of BTU/hr. If the result is less than 50, the boiler
room is a confined space .
Example:
A TWZ090 and a water heater are to be installed in a room measuring 6 ft - 3 in x 7 ft with an 8 ft ceiling. The
water heater has an input of 30000 BTU/hr:
Input of TWZ090 = 0.90 Gal/hr x 140000 BTU/Gal = 126000 BTU/hr
Total input in thousands of BTU/hr = (126000 BTU/hr + 30000 BTU/hr)/1000 = 156
Volume of room = 6.25 ft x 7 ft x 8 ft = 350 ft
3
350/156 = 2.24. Since 2.24 is less than 50, the boiler room is a confined space.
WARNING
• Insufficient combustion air supply may result in the production and release of soot or
deadly carbon monoxide (CO) into the home which can cause property damage, severe
personal injury or death.
• This boiler is not designed for use in a space that is depressurized relative to the outdoors.
Operating this boiler in a depressurized space may cause property damage, severe
personal injury or death.