U.S. Boiler Company INDEPENDENCE IN3PV, Installation & Operating Manual

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rating of 1 perm or less with openings gasketed 

and sealed, and;

b.  Weather-stripping has been added on openable 

windows and doors, and;

c.  Caulking or sealants applied in joints around 

window and door frames, between sole plates 

and floors, between wall-ceiling joints, between 

wall panels, at plumbing and electrical 

penetrations, and at other openings.

5.  For boiler located in an 

unconfined space in a 

building of

other than unusually tight construction

, 

adequate combustion and ventilation air is normally 

provided by fresh air infiltration through cracks 

around windows and doors.

6.  For boiler located within 

unconfined space in 

building of unusually tight construction

 or within 

confined space

, provide outdoor air through two 

permanent openings which communicate directly or 

by duct with the outdoors or spaces (crawl or attic) 

freely communicating with the outdoors. Locate one 

opening within 12 inches of top of space. Locate 

remaining opening within 12 inches of bottom of 

space. Minimum dimension of air opening is 3 

inches. Size each opening per following:
a.  Direct communication with outdoors. Minimum 

free area of 1 square inch per 4,000 Btu per hour 

input of all equipment in space.

b.  Vertical ducts. Minimum free area of 1 square 

inch per 4,000 Btu per hour input of all 

equipment in space. Duct cross-sectional area 

shall be same as opening free area.

c.  Horizontal ducts. Minimum free area of 1 square 

inch per 2,000 Btu per hour input of all 

equipment in space. Duct cross-sectional area 

shall be same as opening free area.

  Alternate method for boiler located within confined 

space. Use indoor air if two permanent openings 

communicate directly with additional space(s) of 

sufficient volume such that combined volume of all 

spaces meet criteria for unconfined space. Size each 

opening for minimum free area of 1 square inch per 

1,000 Btu per hour input of all equipment in spaces, 

but not less than 100 square inches.

7.  Ventilation Duct Louvers and Grilles. Equip outside 

openings with louvers to prevent entrance of rain 

and snow, and screens to prevent entrance of insects 

and rodents. Louvers and grilles must be fixed in 

open position or interlocked with equipment to open 

automatically before burner operation. Screens must 

not be smaller than ¼ inch mesh.

  Consider the blocking effect of louvers, grilles and 

screens when calculating the opening size to provide 

the required free area. If free area of louver or grille 

is not known, assume wood louvers have 20-25 

percent free area and metal louvers and grilles have 

60-75 percent free area.

G

.

  Do not install boiler where gasoline or other flammable 

vapors or liquids, or sources of hydrocarbons (i.e.  

bleaches, cleaners, chemicals, sprays, paint removers, 

fabric softeners, etc.) are used or stored.

CAUTION

Avoid operating this boiler in an environment 

where saw dust, loose insulation fibers, dry wall 

dust, etc. are present.  If boiler is operated under 

these conditions, the burner interior and ports 

must be cleaned and inspected daily to insure 

proper operation.

II. Unpack Boiler

CAUTION

Do not drop boiler.  Do not bump boiler jacket 

against floor.

A.

  Move boiler to approximate installed position.

B.

  Remove all crate fasteners.

C.

  Lift outside container and remove with all other 

inside protective spacers and bracing.  Save two of the 

wooden slats from the container sleeve for use in Steps 

E and F.

D.

  Remove all boiler hold-down fasteners.

E.

  Tilt the boiler to one side and slide a wooden slat under 

the two raised feet.

F.

  Tilt the boiler to the other side and slide another 

wooden slat under the two raised feet.

G.

  Slide the boiler forward or backward off the skid using 

the two wooden slats as runners.

H.

  Move boiler to its permanent location.

I. Pre-Installation (continued)