Lochinvar Copper-Fin II CX401 User manual

DDEESSIIGGNNEERR’’SSGGUUIIDDEECCOOPPPPEERR--FFIINNIIII®®BBOOIILLEERR
400,000 – 2,070,000 Btu/hr

Dear Specifier/Project Manager,
At Lochinvar, we have long recognized the importance of innovation to any
product or service. Those who enter into business must also accept the challenge
of meeting constantly changing needs.
The designer’s guide you are now holding has been designed to make it more
convenient for you to select the perfect Lochinvar boiler for your projects
and provide correct specifications for your teams.
All information has been organized and presented in a succinct, easy-to-use
manner, so you can use and share information confidently and with minimal
effort.
However, it is important to remember that this guide is not intended to replace our
installation manual. Installers should still refer to our installation manual for
specific installation instructions.
We hope our manual will make your work easier and more productive.
As always, we greatly appreciate your input on additional improvements for
the future.
Thanks once again for specifying the Lochinvar family of quality standard
and custom-built water heaters and boilers.
Sincerely,
Lochinvar Corporation
Lochinvar Corporation • 615-889-8900 • Fax: [phone]

Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900 1
Air Removal . . . . . . . . . . . . . . . . . . . . . .23
Boiler Operating Temperature Control . . . .24
Circulator Pump Operation . . . . . . . . . . .18
Codes . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Combustion & Ventilation Air . . . . . . . . . . .6
Contaminants . . . . . . . . . . . . . . . . . . . . . .7
Determining Total “Free Area” . . . . . . . . . .7
Electrical Requirements . . . . . . . . . . . . . . .24
Gas Supply . . . . . . . . . . . . . . . . . . . . . .17
General Venting . . . . . . . . . . . . . . . . . . . .7
Location of Unit . . . . . . . . . . . . . . . . . . . . .2
Low System Water Volume . . . . . . . . . . . .23
Low Water Temperature System . . . . . . . .21
Outdoor Use . . . . . . . . . . . . . . . . . . . . . . .4
Outdoor Installation . . . . . . . . . . . . . . . . .16
Primary/Secondary Piping . . . . . . . . . . . .19
Relief Valve . . . . . . . . . . . . . . . . . . . . . . .20
Remote Temperature Control . . . . . . . . . . .24
Special Design Applications . . . . . . . . . . .22
Variable Speed Pumping . . . . . . . . . . . . .19
Venting Options . . . . . . . . . . . . . . . . . . . .9
Water Flow Requirements . . . . . . . . . . . .18
Water Velocity Control . . . . . . . . . . . . . . .18
Figures & Tables Index
FIG. 1 Models CH 991-2071
Requirements For Installation
Over Combustible Floor . . . . . . .3
FIG. 2 Models CH 401-751 Special
Combustible Floor Base . . . . . . .4
FIG. 3 Boiler Equipment &
Control Orientation . . . . . . . . . . .5
FIG. 4-7 Combustion & Ventilation Air . .6,7
FIG. 8 Barometric Damper Installation . .9
FIG. 9 Multiple Unit Barometric
Damper Installation . . . . . . . . . .10
FIG. 10 Powered Sidewall Venting . . . . .10
FIG. 11 Power DirectAire Horizontal . . .11
FIG. 12 Vertical Vent and Air Inlet . . . . .13
FIG. 13 Vertical Vent and
Sidewall Air Inlet . . . . . . . . . . .13
FIG. 14 Aire-Lock Direct Vent . . . . . . . . .14
FIG. 15 Sidewall Vent . . . . . . . . . . . . . .16
FIG. 16 Outdoor Venting . . . . . . . . . . . .16
FIG. 17 Heat Exchanger Head Loss
Models CH 401-751 . . . . . . . .19
FIG. 18 Heat Exchanger Head Loss
Models CH 991-2071 . . . . . . .19
FIG. 19 Primary/Secondary
System Piping . . . . . . . . . . . . . .20
FIG. 20 High Flow System Piping . . . . . .20
FIG. 21 Low Temperature Bypass
System Piping . . . . . . . . . . . . . .21
FIG. 22 Low Temp Bypass Piping
On/Off . . . . . . . . . . . . . . . . . .22
FIG. 23 Low Temp Bypass Piping
Proportional Stage Firing . . . . . .22
FIG. 24 Heating/Chilled
Water System . . . . . . . . . . . . . .22
FIG. 25 Buffer Tank Piping . . . . . . . . . . .23
TABLE A. Combustible Floor Kits . . . . . . . .3
TABLE B. Clearances From
Combustibles . . . . . . . . . . . . . .4
TABLE C. Flue Sizes and
Inlet Air Pipe Sizes . . . . . . . . . . .9
TABLE D. Powered Sidewall Vent Kits . . .11
TABLE E. Powered DirectAire Horizontal
Vent Kits . . . . . . . . . . . . . . . . .12
TABLE F. DirectAire Vertical Sidewall and
Rooftop Air Inlet Kits . . . . . . . .14
TABLE G. Direct Vent Kits . . . . . . . . . . . . .15
TABLE H. Sidewall Vent Kits . . . . . . . . . . .15
TABLE I. Outdoor Kits . . . . . . . . . . . . . .16
TABLE J. Gas Supply Pipe Sizing . . . . . .17
TABLE K. Inlet Gas Pressure . . . . . . . . . . .18
TABLE L. Water Flow Requirements . . . . .18
TABLE M. Minimum and Maximum
Boiler Flow Rates . . . . . . . . . . .19
TABLE N. Amp Draw Data . . . . . . . . . . . .24
Boiler Piping Diagrams
Primary/Secondary . . . . . . . . . . . . . . . .A1
Multiple Unit Primary/Secondary . . . . . . .A2
Low Temperature Boiler Bypass . . . . . . . .A3
Low Temperature Boiler Bypass w/
3-Way valve . . . . . . . . . . . . . . . . . . . . . .A4
Table of Contents

CODES
The equipment shall be installed in
accordance with those installation
regulations in effect in the local area where
the installation is to be made. These shall
be carefully followed in all cases. Authorities
having jurisdiction shall be consulted before
installations are made.
In the absence of such requirements, the
installation shall conform to the latest edition of
the National Fuel Gas Code, ANSI Z223.1.
Where required by the authority having
jurisdiction, the installation must conform to
American Society of Mechanical Engineers
Safety Code for Controls and Safety Devices
for Automatically Fired Boilers, ASME CSD-1.
Where required by the authority having
jurisdiction, the installation must comply with
the Canadian Association Code, CAN/CGA-
B149.1 and/or B149.2 and/or local codes.
LOCATION OF UNIT
Locate the unit so that if water connections
should leak, water damage will not occur.
When such locations cannot be avoided, it
is recommended that a suitable drain pan,
adequately drained, be installed under the
unit. The pan must not restrict combustion
air flow.
1.
2Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900
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•Water Velocity
(See Page 19 for minimum
and maximum boiler flow rates.)
•Piping Requirements
and Specialties
(See Page 19 for water flow
requirements and system piping.)
•Low Water
Temperature System
(See Page 21 for piping and
design recommendations.)
•System and Boiler
Control
(See Page 24 for boiler operating
and temperature control.)
•Air Elimination and
Expansion Tank Placement
(See Page 23 for air removal
information.)
In designing
a hot water heating
system, pay special
attention to:

The indoor units must be installed so that
the ignition system components are
protected from water (dripping, spraying,
rain, etc.) during appliance operation and
service (circulator replacement, control
replacement, etc.).
The appliance must be installed
on a level, non-combustible floor.
Concrete over wood is not considered a
non-combustible floor. Maintain required
clearances from combustible surfaces.
For installation on a combustible
floor only when installed on
special base: Units installed over a
combustible floor MUST use the Special
Combustible Floor Base. The unit must be
centered on the base as shown in FIG. 1.
• Provide a base of hollow clay tile or
concrete blocks from 8”to 12”thick
and extending 24”beyond the sides.
• The blocks must be placed in line so
that the holes line up horizontally to
provide a clear passage through the
blocks.
• This procedure should also be
followed if electrical conduit or
radiant heat distribution piping
runs through the floor and
beneath the appliance.
• Ensure that combustible floor base
meets local fire code requirements.
• The correct kit number for the required base
is noted on the rating plate of each unit
and listed in Table A.
Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900 3
(TABLE A)
COMBUSTIBLE FLOOR KITS
MODEL NUMBER KIT NUMBER
CH401 CFK3301
CH501 CFK3302
CH651 CFK3303
CH751 CFK3304
2.
3.
4.
(FIG. 1) CH 991-2071 REQUIREMENTS FOR
INSTALLATION OVER COMBUSTIBLE FLOOR
Under no circumstances is the
manufacturer to be held responsible
for water damage in connection
with this unit or any of its
components.

Outdoor models require the installation of
an optional vent cap. Instructions for
placement of the vent cap are included in
the venting section.
Outdoor models must not be installed
directly on the ground. The outdoor unit
must be installed on a concrete brick,
block or other non-combustible pad.
Outdoor models have additional special
location and clearance requirements.
(See Outdoor Installation Pg. 16)
SPECIAL LOCATION:
OUTDOOR USE
Copper-Fin II Models are approved for
outdoor installations. Outdoor models have
additional location and clearance
requirements. These requirements must be
adhered to carefully, since wind, rain, snow
and cold cannot be controlled in outdoor
applications. See Outdoor Installation,
in the venting section on page 16.
5.
(FIG. 2) MODELS CH 401-751 INSTALLED WITH
OPTIONAL COMBUSTIBLE FLOOR BASE
4Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900
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(TABLE B) – CLEARANCES FROM COMBUSTIBLES
CLEARANCES CH401-751 CH991-2071
Right Side 1”3”
Rear 1”3”
Left Side 6”3”
(24” for Service) (24” for Service)
Front ALCOVE* ALCOVE*
(24” for Service) (30” for Service)
Top 1”3”
Flue 1”+1”+
Hot Water Pipes 1”1”
* Alcove is a closet without a door.
+ Consult local codes and/or vent manufacturer.

Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900 5
(FIG. 3) BOILER EQUIPMENT AND CONTROL ORIENTATION.
FLUE PRODUCTS VENT
GAS CONNECTION
TERMINAL STRIP
DRAIN
BURNER INSPECTION PORT
OPERATOR INTERFACE PANEL
LEFT SIDE
FRONT
GAS
CONNECTION
DRAIN
LEFT SIDE OPERATOR INTERFACE PANEL
BURNER INSPECTION PORT
FRONT
AIR INLET
SYSTEM SUPPLY
SYSTEM
RETURN
FLUE PRODUCTS VENT
BACK
BACK
SYSTEM RETURN
120V ELECTRICAL
CONNECTION
TERMINAL
STRIP
SYSTEM SUPPLY
AIR INLET
CH 401-751
CH 991-2071

6Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900
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EXAMPLE OF SIZING
FOR COMBUSTION
& VENTILATION AIR
OPENINGS (BOILER
WITH 2,070,000
Btu/hr
When combustion and
ventilated air is taken
from directly outside the
building (FIG. 4), divide
the total BTU’s by 4,000.
This yields 517.5 sq.in.
of “Free Area” without
restriction.
(2,070,000 ÷ 4000 =
517.5 sq.in.)
Since the air opening is
50% closed due to
screens and louvers, the
total opening MUST be
multiplied by 2.
(517.5 sq. in. x 2 =
1,035 sq.in.)
This project requires one
Ventilation Air Opening
with a net area of 1,035
square inches with louver
dimensions of 30” x 35”
and one Combustion Air
Opening with a net area
of 1,050 square inches
with louver dimensions
of 30” x 35”.
COMBUSTION &
VENTILATION AIR
Provisions for combustion and ventilation air
must be in accordance with Section 5.3,
Air for Combustion and Ventilation, of the
latest edition of the National Fuel Gas
Code, ANSI Z223.1; in Canada, the latest
edition of CGA Standard B149 Installation
Code for Gas Burning Appliances and
Equipment; or applicable provisions of the
local building codes.
The equipment room must be provided with
properly sized openings to assure adequate
combustion air and proper ventilation when
the unit is installed with conventional venting
or sidewall venting.
If air is taken directly from outside
the building with no duct, provide two
permanent openings:
A. Combustion air opening with a
minimum free area of one square inch per
4000 Btu input (5.5 cm2per kW).
This opening must be located within 12”
(30 cm) of the bottom of the enclosure.
B. Ventilation air opening with a minimum
free area of one square inch per 4000
Btu input (5.5 cm2per kW). This opening
must be located within 12”(30 cm) of the
top of the enclosure.
If combustion and ventilation air is
taken from the outdoors using a
duct to deliver the air to the
mechanical room, each of the two
openings should be sized based on a
minimum free area of one square inch
per 2000 Btu input (11cm2per kW).
If air is taken from another interior
space, each of the two openings
specified above should have a net free
2.
3.
(FIG. 4) COMBUSTION AIR DIRECT FROM OUTSIDE
(FIG. 5) COMBUSTION AIR THROUGH DUCTWORK
(FIG. 6) COMBUSTION AIR FROM AN
INTERIOR SPACE
CAUTION: Under no circumstances should
the equipment room be under a negative
pressure when atmospheric combustion
equipment is installed in the room.

Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900 7
CAUTION!
EXHAUST FANS:
Any fan or
equipment
which exhausts
air from the
equipment room
may deplete the
combustion air
supply and/or
cause a down
draft in the
venting system.
If a fan is used
to supply
combustion air
to the
equipment
room, it MUST
be sized to
make sure that
it does not
cause drafts
which could
lead to nuisance
operational
problems with
the boiler.
area of one square inch for each 1000
Btu (22 cm2per kW) of input, but not less
than 100 square inches (645 cm2).
If a single combustion air opening
is provided to bring combustion
air in directly from the outdoors,
the opening must be sized based on a
minimum free area of one square inch
per 3000 Btu input (7 cm2per kW). This
opening must be located within 12”
(30 cm) of the top of the enclosure.
CONTAMINANTS
Combustion air drawn from an interior
or exterior space must be free of any
chemical fumes which could be corrosive to
the water heater.
Burning chemical fumes results in the
formation of corrosive acids which attack the
water heater, cause improper combustion
and premature failure of the water heater
and vent.
These fumes are often present in areas
where refrigerants, salts, and solvents are
used. Therefore, be aware of swimming
pool equipment, water softening, and
cooling system placement.
VENTING
General
These boilers are classified as Category I
appliances when tested to the latest ANSI
Standard. This classification requires all
conventionally vented combustion products
to be vented using Category I listed vent
pipe.
Additionally, it is recommended that this vent
material be double wall construction or
insulated in the field. A Category I
appliance operates with a non-positive static
vent pressure and with flue loss greater than
17 percent.
Vent installations for connection to gas vents
or chimneys must be in accordance with
Part 7, “Venting of Equipment,” of the latest
edition of the National Fuel Gas Code, ANSI
Z223.1, or applicable provisions of the local
building codes.
The connection from the appliance vent
to the stack must be as direct as possible
and sized correctly. The horizontal breeching
of a vent must have at least 1/4”rise per
linear foot. The horizontal portions should
also be supported for the design and weight
of the material employed to maintain
clearances, prevent physical damage and
separation of joints.
The connection from the appliance vent
to the stack or vent termination outside the
building must be made with listed
4.
(FIG. 7) COMBUSTION AIR FROM OUTSIDE,
SINGLE OPENING

8Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900
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NOTE:
Flue gases will
form a white
plume in winter.
Plume could
obstruct window
view. Flue gas
condensate can
freeze on
exterior surfaces
or on the vent
cap. Flue gas
condensate can
cause
discoloration of
exterior building
surfaces.
Adjacent brick or
masonry
surfaces should
be protected
with a rust
resistant sheet
metal plate.
Category I double wall vent (or equivalent)
connectors and sized according to vent
sizing tables (FAN column) in the latest
edition of the National Fuel Gas Code.
The Category I vent and accessories, such as
firestop spacers, thimbles, caps, etc., must
be installed in accordance with the vent
manufacturer’s listing. The vent connector and
firestop must provide correct spacing to
combustible surfaces and seal to the vent
connector on the upper and lower sides of
each floor or ceiling through which the vent
connector passes.
Any improper operation of the common
venting system in an existing building should
be corrected when new equipment is
installed, so the installation conforms to the
latest edition of the National Fuel Gas Code,
ANSI Z223.1.
When resizing any portion of the common
venting system, it should be resized to
approach the minimum size as determined
using the appropriate tables in the National
Fuel Gas Code.
The weight of the venting system must not
rest on the water heater. The venting system
must be adequately supported in
compliance with local codes and other
applicable codes.
Vent Terminations
The vent terminal should be vertical and
exhaust outside the building at least 2 feet
(0.6 m) above the highest point of the roof
when within a 10 foot (3.05 m) radius.
Additionally, vertical terminations must be a
minimum of 3 feet (0.9 m) above the roof
line, and when less than 10 feet (3.05 m)
from a parapet wall must be a minimum of
2 feet (0.61 m) higher than the parapet wall.
Vent caps should have a minimum clearance
of 4 feet (1.2 m) horizontally from, and in no
case above or below [unless a 4 feet (1.2 m)
horizontal distance is maintained], electric
meters, gas meters, regulators and relief
equipment.
Maintain a distance of at least 3 feet
(0.9 m) above any forced air inlet within
10 feet (3.05 m) and a distance of at least
4 feet (1.2 m) below, 4 feet (1.2 m)
horizontally from, or 1 foot (30 cm) above
any door, window or gravity air inlet.
Do not terminate the vent in a window well,
stairwell, alcove, courtyard or other recessed
area. The vent can not terminate
below grade. The bottom of the vent
terminal shall be located at least 12 inches
(30 cm) above grade and clear of snow,
ice, leaves or other debris.
The distance of the vent terminal from
adjacent public walkways, adjacent
buildings, windows, and building openings

must be consistent with the National Fuel
Gas Code Z223.1 or in Canada, the latest
edition of CGA Standard B149 Installation
Code for Gas Burning Appliances and
Equipment.
VENTING OPTIONS
Conventional Venting
A conventional venting system utilizes
the natural buoyancy of the heated flue
products to generate a negative draft. This
draft forces flue products to rise vertically
through a rooftop flue termination. The vent
connection is made directly to the top of the
unit and combustion air supplied from the
mechanical room. Properly sizing vent
material and the use of a barometric
damper (when required) will lead to proper
vent operation.
A barometric damper is required when draft
exceeds 0.08 inches of negative water
column. When installed and adjusted
properly, a barometric damper will maintain
draft between 0.02 and 0.08 inches of
negative water column ensuring proper
operation.
The minimum flue pipe diameters for all
models, utilizing negative draft venting are
as follows:
Size vent material using the “FAN” category
of vent sizing tables in the latest edition of
the National Fuel Gas Code. “FAN” applies
to fan-assisted combustion appliances in
Category I.
Multiple unit installations with combined
venting also require barometric dampers to
regulate draft at each unit. Again, the
negative draft must be within the range of
0.02 to 0.08 inches of negative water
column to ensure proper operation.
Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900 9
(TABLE C)
FLUE SIZES AND INLET AIR PIPE SIZES
MODEL FLUE SIZE DIRECTAIRE
NUMBER INLET SIZE
CH401 6”6”
CH501 6”6”
CH651 8”8”
CH751 8”8”
CH991 10”10”
CH1261 12”12”
CH1441 12”12”
CH1801 14”12”
CH2071 14”12”
(FIG. 8) BAROMETRIC DAMPER INSTALLATION

10 Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900
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NOTE:
Venting of a
high efficiency
appliance into a
cold or
oversized
masonry
chimney can
result in
operational and
safety problems.
For this type of installation, it is best to use a
draft control for each water heater located
on the riser between the vent outlet and the
breeching - Location “A”. When this riser is
too short to permit the installation of a draft
control, locate a separate control for each
water heater on the main breeching as
illustrated in Location “B”. If, because of
general crowding or other reasons, neither
of these locations are possible, use a single
large control in the breeching between the
water heater nearest the chimney and the
chimney, as shown in Location “C”.
All draft readings are made while unit is in
stable operation (approximately 5 minutes
running time).
Masonry Chimney
A masonry chimney must be properly sized
for the installation of a high efficiency gas
fired appliance. Exterior masonry chimneys,
with one or more sides exposed to cold
outdoor temperatures, are more likely to
have venting problems. The temperature of
the flue products from a high efficiency
appliance may not be able to sufficiently
heat the masonry structure of the chimney to
generate proper draft. This will result in
condensing of flue products, damage of the
masonry flue/tile, insufficient draft and
possible spillage of flue products into an
occupied living space.
Carefully inspect all chimney systems during
the project design phase. If there is any doubt
about the sizing or condition of a masonry
chimney, it is prudent to reline the chimney
with a properly sized and approved chimney
liner system. Metallic liner systems (Type “B”
doublewall or flexible or rigid metallic liners)
are recommended. Consult with local code
officials to determine code requirements or the
advisability of using or relining a masonry
chimney.
Powered Sidewall Venting
This venting system uses a powered
vent cap assembly which pulls the flue products
out of the stack. The fan in the powered vent
cap generates a negative draft at the unit.
Combustion air is drawn from the mechanical
room (See Combustion and Ventilation Air
Requirements, page 6).
(FIG. 9) MULTIPLE UNIT BAROMETRIC
DAMPER INSTALLATION
(FIG. 10) POWERED SIDEWALL VENTING
(POWERED VENT CAP SHOWN)
NOTE:
Common venting
systems may be
too large when
an existing unit
is removed. Be
careful to resize
any common
venting system
when new
appliances are
installed or
existing
appliances are
replaced.

Powered Sidewall Vent Kits
Models CH401-751 utilize a powered vent cap
which has a fan mounted inside the cap. The
powered vent cap must be placed on an
exterior wall. The powered sidewall vent cap
and accessories are included in a venting kit,
which must be furnished by Lochinvar in
accordance with CSA International requirements.
This venting kit includes the powered sidewall
fan/cap, proving switch and all necessary relays
to interlock with the water heater control system.
Models CH991-2071 utilize an inline fan,
which is positioned on the inside of the sidewall
and connected to a vent hood mounted on the
sidewall exterior. The inline fan and accessories
are included in a venting kit, which must be
furnished by Lochinvar in accordance with CSA
International requirements.
This venting kit includes the inline fan, exterior
vent hood, a tapered vent adapter, barometric
damper, proving switch and all necessary relays
to interlock with the water heater control system.
The connection from the vent to the sidewall
fan/powered vent cap must be made with
listed Type “B” double wall
(or equivalent) vent and accessories. The installer
supplies this vent pipe material.
For models CH401-751, maximum total
equivalent length of the vent pipe cannot
exceed 50 equivalent feet (15.24 m).
Models CH991-2071 allow a maximum
total equivalent length of 100 feet (30.48 m).
Subtract 5 feet (1.52 m) for each elbow in the
vent.
Powered DirectAire® Horizontal
This vent system requires the installation of
two vent pipes directly to the unit, one pipe
for flue products and one for combustion air.
Both vent pipes are installed horizontally with
a sidewall termination point. The vent
connection is made directly to the top of the unit
and utilizes either the powered vent cap or inline
fan as described in the power side wall venting
section.
Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900 11
(TABLE D) – POWERED SIDEWALL VENT KIT PART NUMBERS
MODEL FLUE SIZE SIDEWALL VENT
NUMBER CAP KIT
CH401 6”SVK3006
CH501 6”SVK3006
CH651 8”SVK3008
CH751 8”SVK3008
CH991 10”SVK3009
CH1261 12”SVK3010
CH1441 12”SVK3011
CH1801 14”SVK3012
CH2071 14”SVK3012
(FIG. 11) POWERED DIRECTAIRE®HORIZONTAL
(POWERED VENT CAP SHOWN)
3’
12”

Lochinvar
12 Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900
The combustion air supply system has specific
vent material and installation requirements.
The air inlet pipe connects directly to the
water heater to supply combustion air. The
combustion air inlet pipe will be a dedicated
system with one air inlet pipe per water
heater. The air inlet pipe must be connected
to a combustion air inlet cap.
To prevent recirculation of flue products from an
adjacent vent cap into the combustion air inlet,
follow all applicable clearance requirements in
the latest edition of the National Fuel Gas Code
and the following instructions:
The combustion air inlet cap must be installed
at least 1 foot (0.30 m) above ground level and
above normal snow levels.
The point of termination for the combustion air
inlet cap must be at least 3 feet (0.91 m)
below the point of flue gas termination if it is
located within 10 feet (3.05 m) of the flue outlet.
The combustion air inlet cap must not be
installed closer than 10 feet (3.05 m) from an
inside corner of an L-shaped structure.
Both the combustion air inlet cap and the
powered vent cap/inline fan vent hood must
be installed on the same wall and in the same
pressure zone.
The Horizontal DirectAire system requires
installation of a single wall pipe to supply
combustion air from outdoors directly to the
water heater. The use of double wall vent
material is recommended in cold climates to
prevent the condensation of airborne moisture.
For models CH401-751, maximum total
equivalent length of the vent pipe and
combustion air inlet pipe cannot exceed
50 equivalent feet (15.24 m). Models
CH991-2071 allow a maximum total equivalent
length of 100 feet (30.48 m) for each pipe.
Subtract 5 feet (1.52 m) for each elbow in
the vent.
Powered DirectAire®Horizontal Kits
Models CH401-751 vent kit includes the
powered sidewall fan/cap, proving switch, air
inlet cap and all necessary relays to interlock
with the water heater control system. Lochinvar
must furnish this vent kit in accordance with
CSA International requirements.
Models CH991-2071 vent kit includes the inline
fan, exterior vent hood, a tapered vent adapter,
barometric damper, proving switch, air inlet cap
and all necessary relays to interlock with the
water heater control system. Lochinvar must
furnish this vent kit in accordance with CSA
International requirements.
The installer supplies all vent pipe
material.
(TABLE E) POWERED DIRECTAIRE
®
HORIZONTAL
KIT PART NUMBERS
MODEL FLUE SIZE DIRECT AIR HORIZONTAL
NUMBER INLET SIZE DIRECTAIRE KIT
CH401 6
”
6
”
HDK3031
CH501 6
”
6
”
HDK3031
CH651 8
”
8
”
HDK3032
CH751 8
”
8
”
HDK3032
CH991 10
”
10
”
HDK3026
CH1261 12
”
12
”
HDK3027
CH1441 12
”
12
”
HDK3027
CH1801 14
”
12
”
HDK3028
CH2071 14
”
12
”
HDK3028

Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900 13
NOTE:
The use of
double wall vent
material
for the
combustion air
inlet pipe is
recommended in
cold climates to
prevent the
accumulation of
condensation on
the pipe
exterior.
CAUTION!
Boilers which
are shut down
or will not
operate may
experience
freezing due to
convective air
flow in the air
inlet pipe
connected to the
unit. Proper
freeze
protection MUST
be provided.
DirectAire® Vertical
This vent system requires the installation of two
pipes directly to the unit, one vertical pipe with
a roof top termination for the flue products and
one pipe for combustion air. The combustion
air pipe may terminate horizontally with a
sidewall air inlet or vertically with a roof top
air inlet. Vent connection is made directly to
the top of the unit.
No additional draft diverter or barometric
damper is required on single unit installations
with a dedicated stack and a negative draft
maintained between 0.02 to 0.08 inches of
negative water column. The flue may be
combined with the vent from any other
negative draft, Category I appliances.
Multiple unit installations common vented
with other negative draft appliances require
that each water heater must have a
barometric damper. The common vent and
connectors from multiple water heaters must
be sized per the requirements of the venting
tables for Type “B” double wall vents in the
latest edition of the National Fuel Gas Code,
ANSI Z223.1.
The air inlet pipe connects directly to the
water heater to supply combustion air. The
maximum distance for the air inlet pipe is 50
equivalent feet. Subtract 5 feet (1.52 m) for
each elbow in the air inlet pipe.
Single wall vent material is used to supply
the combustion air to each unit. The use of
double wall vent material is recommended
in cold climates to prevent the condensation
of airborne moisture.
To prevent recirculation of flue products from
an adjacent vent cap into the combustion air
inlet, follow all applicable clearance
requirements in the latest edition of the
National Fuel Gas Code and instructions in
this manual.
The combustion air inlet cap must be
installed at least one foot (0.30 m) above
ground level and above normal snow levels.
The point of termination for the combustion air
inlet cap must be at least 3 feet (0.91 m)
below the point of flue gas termination (vent
cap), if it is located within 10 feet (3.05 m) of
the flue outlet.
(FIG. 12) VERTICAL VENT AND AIR INLET
3’
12”
(FIG. 13) VERTICAL VENT
AND SIDEWALL AIR INLET

14 Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900
Lochinvar
The combustion air inlet cap must not be
installed closer than 10 feet (3.05 m) from an
inside corner of an L-shaped structure.
The vertical air inlet point for the combustion
air inlet cap must be installed at least one
foot (0.30 m) above the rooftop and above
normal snow levels. Lochinvar is required to
supply a vent kit for DirectAire applications.
Each kit includes either a sidewall or roof top
combustion air inlet cap to supply air to a
single water heater (See Table F).
Aire-LockTM Direct Vent
This vent system utilizes the internal blower of
the unit to draw all combustion air from
outside and vent the by-products of
combustion to the outdoors. This vent system
requires the installation of two vent pipes
directly to the unit, one pipe for flue products
and one pipe for combustion air. Both vent
pipes can terminate horizontally at a sidewall
or vertically at the rooftop. It is a requirement
that both vent pipes terminate in the same
pressure zone. The vent system has specific
vent material and installation requirements.
The vent piping for flue products uses AL29-
4C vent material and must be sealed “gas-
tight” at all vent joints. The vent connection is
made directly to the top of the unit. The
maximum distance for the flue pipe is 50
equivalent feet (15.2 m). Subtract 5 feet
(1.52 m) for each elbow in the flue pipe.
The flue products vent pipe is a dedicated
system with one flue pipe per unit.
The combustion air supply pipe connects
directly to the unit to supply combustion air.
The maximum distance for the air inlet pipe is
50 equivalent feet (15.2 m). Subtract 5 feet
(1.52 m) for each elbow in the air inlet pipe.
(TABLE F)
DIRECTAIRE VERTICAL SIDEWALL & ROOFTOP AIR INLET KITS
MODEL NUMBER VENT SIZE AIR INLET SIDEWALL AIR ROOFTOP AIR
SIZE* INLET KIT INLET KIT
CH401 6”6”SVK3047 VDK3026
CH501 6”6”SVK3047 VDK3026
CH651 8”8”SVK3048 VDK3027
CH751 8”8”SVK3048 VDK3027
CH991 10”10”SVK3040 VDK3023
CH1261 12”12”SVK3041 VDK3024
CH1441 12”12”SVK3041 VDK3024
CH1801 14”12”SVK3041 VDK3024
CH2071 14”12” SVK3041 VDK3024
(FIG. 14) AIRE-LOCK DIRECT VENT

Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900 15
The combustion air inlet pipe is a dedicated
system with one air inlet pipe per unit. The air
inlet pipe must be connected to the Direct Vent
(DV) box adapter. The air inlet pipe must be
sealed.
Aire-LockTM Horizontal Direct Vent Kits
The vent kit includes a DV box adapter; sidewall
air inlet cap and sidewall vent termination.
Lochinvar must furnish this vent kit in accordance
with CSA International requirements.
Vertical Direct Vent Termination
You must use the vent termination
recommended by the vent manufacturer for
vertical direct vent terminations.
The installer supplies all vent pipe
material.
The combustion air inlet cap must be
installed at least 1 foot (0.30 m) above
ground level and above normal snow levels.
The point of termination for the combustion air
inlet cap must be at least 3 feet (0.91 m)
below the point of flue gas termination if it is
located within 10 feet (3.05 m) of the flue outlet.
The combustion air inlet cap must not be
installed closer than 10 feet (3.05 m) from an
inside corner of an L-shaped structure.
Both the combustion air inlet cap and flue gas
vent termination must be installed in the
same pressure zone.
Sidewall Vent
This vent system utilizes the internal blower of
the unit to vent the by-products of combustion
to the outdoors. This vent system requires the
installation of one pipe for flue products. The
vent pipes terminates horizontally at a
sidewall. The vent system has specific vent
material and installation requirements. The
vent piping for flue products uses AL29-4C
vent material and must be sealed "gastight"
at all vent joints. The vent connection is made
directly to the top of the unit. The maximum
distance for the flue pipe is 50 equivalent feet
(15.2m). Subtract 5 feet (1.52m) for each
elbow in the flue pipe. The flue products vent
pipe is a dedicated system with one flue pipe
per unit.
Sidewall Vent Kits
The vent kit includes a sidewall vent termination
assembly to provide pressure equalization.
Lochinvar must furnish this vent kit in accordance
with CSA International requirements.
(TABLE G)
AIRE-LOCKTM DIRECT VENT KIT PART NUMBERS
MODEL FLUE AIR PART
NUMBER SIZE INLET SIZE NUMBER
CH401 6
”
6
”
DVK3004
CH501 6
”
6
”
DVK3004
CH651 8
”
8
”
DVK3005
CH751 8
”
8
”
DVK3005
CH991 10
”
10
”
DVK3000
CH1261 12
”
12
”
DVK3001
CH1441 12
”
12
”
DVK3001
CH1801 14
”
12
”
DVK3002
CH2071 14
”
12
”
DVK3002
(FIG. 15) SIDEWALL VENT

16 Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900
Lochinvar
The installer supplies all vent pipe
material.
Combined Air Inlet Points
In most installations, the combustion air inlet
pipe will be a dedicated system with one air
inlet pipe per water heater.
Multiple air inlets may be combined to a
single common connection if the common air
inlet pipe has a cross sectional area equal to
or larger than the total area of all air inlet
pipes connected to the common air inlet pipe.
The air inlet point for multiple water heater air
inlets must be provided with an exterior
opening which has a free area equal to or
greater than the total area of all air inlet pipes
connected to the common air inlet. This
exterior opening for combustion air must
connect directly to the outdoors.
The total length of the combined air inlet pipe
must not exceed a maximum of 50 (15.25
m) equivalent feet. Subtract 5 feet (1.52 m)
for each elbow in the air inlet pipe.
Deduct the restriction in area provided by any
screens, grills or louvers installed in the
common air inlet point. These are common on
the sidewall air inlet openings. Screens, grills
or louvers installed in the common air inlet
can reduce the free area of the opening from
25% to 75% based on the materials used.
OUTDOOR INSTALLATION
Units are self venting and can be used
outdoors when installed with the optional
Outdoor Cap. This cap mounts directly to the
top of the water heater and covers the flue
outlet and combustion air inlet openings on
the jacket. No additional vent piping is
required. Maintain a minimum clearance of
3”(76 mm) to combustible surfaces and a
minimum of 3”(76 mm) clearance to the air
inlet.
An outdoor unit should not be located so that
high winds can deflect off of adjacent walls,
buildings or shrubbery causing recirculation.
Recirculation of flue products may cause
operational problems, bad combustion or
damage to controls. The unit should be
located at least 3 feet (0.91m) from any wall
or vertical surface to prevent adverse wind
conditions from affecting performance.
Multiple unit outdoor installations require 48”
(1.22 m) clearance between each vent cap.
The outdoor cap must be located 4 feet
(1.22 m) below and 4 feet (1.22 m)
horizontally from any window, door,
walkway or gravity air intake.
(FIG. 16) OUTDOOR VENTING
(TABLE H)
SIDEWALL VENT KIT PART NUMBERS
MODEL FLUE PART
NUMBER SIZE NUMBER
CH401 6
”
SVK3043
CH501 6
”
SVK3043
CH651 8
”
SVK3044
CH751 8
”
SVK3044

The combustion air inlet of the outdoor cap
must be located at least one foot (0.30 m)
above grade and above normal snow
levels. The water heater must be at least 10
feet (3.05 m) away from any forced air inlet
and at least 3 feet (0.91 m) outside any
overhang.
Do not install in locations where rain from
building runoff drains will spill onto the
water heater.
Lochinvar must furnish an outdoor vent kit
in accordance with CSA international
requirements. Each kit includes the flue
outlet/combustion air inlet, assembly, and
gasket.
Freeze Protection-
Outdoor Installation
A snow screen should be installed to prevent
snow and ice accumulation around the
appliance or its venting system.
If for any reason the unit is to be shut off:
(a.) Shut off water supply.
(b.) Drain unit completely.
(c.) Drain pump and piping.
If freeze protection is not provided for the
system, a low ambient temperature alarm or
automatic drain system is recommended.
GAS SUPPLY
Safe operation of unit requires properly
sized gas supply piping (See TABLE J).
Gas pipe size may be larger than the
heater connection.
A gas pressure regulator is suggested to
help assure proper inlet gas pressure. If
upstream pressure exceeds 6 oz. (10.5
inches of water column), an intermediate
gas pressure regulator, of the lockup type,
must be installed.
Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900 17
(TABLE I) - OUTDOOR VENT CAP PART NUMBERS
MODEL
NUMBER PART NUMBER
CH401 0DK3019
CH501 0DK3020
CH651 0DK3021
CH751 ODK3022
CH991 ODK3036
CH1261 ODK3037
CH1441 ODK3037
CH1801 ODK3038
CH2071 ODK3038
(TABLE J) – GAS SUPPLY PIPE SIZING
Length of Pipe In Straight Feet
Nominal Iron
Pipe Size, Inches 10 20 30 40 50 60 70 80 90 100 125 150 175 200
369 256 205 174 155 141 128 121 113 106 95 86 79 74
697 477 384 328 292 267 256 246 210 200 179 164 149 138
1,400 974 789 677 595 543 502 472 441 410 369 333 308 287
2,150 1,500 1,210 1,020 923 830 769 707 666 636 564 513 472 441
4,100 2,820 2,260 1,950 1,720 1,560 1,440 1,330 1,250 1,180 1,100 974 871 820
6,460 4,460 3,610 3,100 2,720 2,460 2,310 2,100 2,000 1,900 1,700 1,540 1,400 1,300
11,200 7,900 6,400 5,400 4,870 4,410 4,000 3,800 3,540 3,300 3,000 2,720 2,500 2,340
23,500 16,100 13,100 11,100 10,000 9,000 8,300 7,690 7,380 6,870 6,150 5,640 5,130 4,720
Maximum capacity of pipe in thousands of BTU’s per hour for gas pressures of 14” Inches Water Column (0.5 PSIG) or less and a total
system pressure drop of 0.05 Inch Water Column (Based on NAT GAS, 1025 BTU’s per Cubic Foot of Gas and 0.60 Specific Gravity).
11 /4
3
/4
11 /2
1
21
/2
31 /2
3
2
1.
2.
3.

18 Lochinvar DESIGNER’S GUIDE COPPER-FIN II BOILER 615-889-8900
Lochinvar
Installation of a union is suggested for
ease of service.
Install a manual main gas shut-off valve
with test plug, outside of the appliance
gas connection and before the gas valve,
when local codes require.
A trap (drip leg) should be provided in
the inlet of the gas connection to the unit.
High Altitude Applications
Atmospheric pressure decreases as the
height above sea level increases. At any
altitude above sea level, a cubic foot will
contain less gas than a cubic foot at sea
level. Thus, the heating value of a cubic foot
of fuel gas will decrease as height above
sea level increases.
Specific gravity of a gas with respect to sea
level also decreases with altitude. These
changes in heating value and specific
gravity tend to offset each other.
However, as elevation above sea level is
increased, there is less oxygen per cubic foot
of air. Therefore, heat input rate should be
reduced in an appliance above 2000 feet.
Ratings should be reduced at the rate of 4
percent for each 1000 feet above sea level.
WATER CONNECTIONS
Inlet and Outlet Water Connections
For ease of service, install unions on inlet and
outlet of the boiler.
The connection on the unit marked “Inlet”
should be used for return water from the system.
The connection on the header marked “Outlet”
should be connected to the system supply. (See
Boiler Piping Diagrams, Appendix A).
WATER VELOCITY CONTROL
IMPORTANT - To ensure proper velocity
through the heat exchanger, it is necessary to
regulate the temperature rise across the heat
exchanger from inlet to outlet. (This must be
done on initial installation and periodically
rechecked). With the correct temperature rise
across the heat exchanger (See TABLE L), you
may be assured of the proper velocity in the
tubes and long life and economical operation
from the boiler.
GPM
45
57
64*
-
-
-
-
-
-
FT. HD
4.9
5.1
5.7
-
-
-
-
-
-
GPM
34
42
55
64*
83
106*
-
-
-
FT. HD
2.4
4.1
5.2
5.3
5.4
8.4
-
-
-
GPM
27
34
44
51
67
86
100*
-
-
FT. HD
1.8
2.9
4.1
4.8
5.6
6.9
9.1
-
-
GPM
23
28
37
42
55
71
81
101*
-
GPM
19
24
32
36
48
61
70
87
97*
FT. HD
1.1
1.6
3.0
4.1
2.6
4.4
6.3
10.1
-
FT. HD
0.9
1.2
2.3
3.2
2.1
4.0
5.7
8.3
10.7
GPM
17
21
28
32
42
53
61
76
87
FT. HD
0.6
0.7
1.6
2.3
1.5
2.7
3.8
6.6
9.0
INPUT
400,000
500,000
650,000
750,000
990,000
1,260,000
1,440,000
1,800,000
2,070,000
OUTPUT
336,000
420,000
546,000
630,000
831,000
1,058,400
1,209,600
1,512,000
1,738,800
TEMPERATURE RISE 15°F ΔΔT 20°F ΔΔT 25°F ΔΔT 30°F ΔΔT35°F ΔΔT40°F ΔΔT
(TABLE L) – WATER FLOW REQUIREMENTS
(TABLE K) – INLET GAS PRESSURE
MODELS NAT. GAS LPG
CH401-751
Maximum Allowable 10.5”13”
Minimum Allowable 4.5”8”
CH991-2071
Maximum Allowable 10.5”13”
Minimum Allowable 5”11”
4.
5.
6.
EXAMPLE OF
HIGH ALTITUDE
APPLICATIONS
For example, if a
unit’s input is
100,000 Btu/hr
at sea level, the
rated input at
4000 feet of
elevation can be
calculated by
derating input
4% per 1000 feet
above sea level.
[Btu/hr Input]
[1.00 - (Elevation
÷ 1000’ x 0.04)]
= Btu/hr Input at
Specified
Elevation
[100,000] [1.00 -
(4000’ ÷ 1000’ x
0.04)] = Btu/hr
Input at 4000’
Elevation
[100,000] [0.84]
= 84,000 Btu/hr
Input at 4000’
Elevation
NOTE: In Table L * indicates flows in excess of maximum
flow rating for copper tube HEX. Cupronickel tube HEX
are recomended for these flow rates.