LAARS Mighty Therm2 MT2V (Sizes 500–2000 MBTU/h) - Install and Operating Manual - Manual (Page 12)

LAARS Heating Systems Page 12
SIZE DISTANCE FROM GAS METER
AND OR LAST STAGE REGULATOR
GAS TYPE 0-100' 100-200' 200-300'
500 natural 1½" 2" 2"
500 propane 1" 1½" 1½"
750 natural 2" 2" 2½"
750 propane 1½" 1½" 2"
1000 natural 2" 2½" 3"
1000 propane 1½" 2" 2½"
1250 natural 2½" 2½" 3"
1250 propane 2" 2" 2½"
1500 natural 2½" 3" 3"
1500 propane 2" 2½" 2½"
1750 natural 2½" 3" 3"
1750 propane 2" 2½" 2½"
2000 natural 3" 3" 3½"
2000 propane 2½" 2½" 3"
Metric Equivalent
SIZE DISTANCE FROM GAS METER
AND OR LAST STAGE REGULATOR
GAS TYPE 0-31m 31-61m 61-91m
500 natural 3.8cm 5.1cm 5.1cm
500 propane 2.5cm 3.8cm 3.8cm
750 natural 5.1cm 5.1cm 6.4cm
750 propane 3.8cm 3.8cm 5.1cm
1000 natural 5.1cm 6.4cm 7.6cm
1000 propane 3.8cm 5.1cm 6.4cm
1250 natural 6.4cm 6.4cm 7.6cm
1250 propane 5.1cm 5.1cm 6.4cm
1500 natural 6.4cm 7.6cm 7.6cm
1500 propane 5.1cm 6.4cm 6.4cm
1750 natural 6.4cm 7.6cm 7.6cm
1750 propane 5.1cm 6.4cm 6.4cm
2000 natural 7.6cm 7.6cm 8.9cm
2000 propane 6.4cm 6.4cm 7.6cm
NOTES: 1. These figures are based on 1/2" (0.12kPa) water column
pressure drop.
2. Check supply pressure and local code requirements
before proceeding with work.
3. Pipe fittings must be considered when determining gas
pipe sizing.
Table 7. Gas Piping Sizes.
remaining connected to it.
At the time of removal of an existing boiler, the
following steps shall be followed with each appliance
remaining connected to the common venting system
placed in operation, while the other appliances remain-
ing connected to the common venting system are not in
operation.
1. Seal any unused openings in the common venting
system.
2. Visually inspect the venting system for proper
size and horizontal pitch and determine there is
no blockage or restriction, leakage, corrosion and
other deficiencies which could cause an unsafe
condition.
3. Insofar as it is practical, close all building doors
and windows and all doors between the space in
which the appliances remaining connected to the
common venting system are located and other
spaces of the building. Turn on clothes dryers
and any appliance not connected to the common
venting system. Turn on any exhaust fans, such
as range hoods and bathroom exhausts, so they
will operate at maximum speed. Do not operate a
summer exhaust fan. Close fireplace dampers.
4. Place in operation the appliance being inspected.
Follow the lighting instructions. Adjust thermostat
so appliance will operate continuously.
5. Test for spillage at the draft hood relief opening
after 5 minutes of main burner operation. Use
the flame of a match or candle, or smoke from a
cigarette, cigar or pipe.
6. After it has been determined that each appliance
remaining connected to the common venting
system properly vents when tested as outlined
above, return doors, windows, exhaust fans,
fireplace dampers and any other gas burning
appliance to their previous conditions of use.
7. Any improper operation of the common venting
system should be corrected so that the installation
conforms to the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 and/or CSA B149.1, Installation
Codes. When resizing any portion of the common
venting system, the common venting system
should be resized to approach the minimum size as
determined using the appropriate tables in Part II of
the National Fuel Gas Code, ANSI Z223.1/NFPA
54 and/or CSA B149.1, Installation Codes.
2.5 Vent Terminals for Outdoor Units
For outdoor applications, the vent and combustion
air openings must be covered with proper terminals to
prevent rain, snow and other objects from falling into the
Mighty Therm2.
If local codes allow, outdoor installations may
use 1' of appropriately sized galvanized single wall or
B-Vent and a rain cap for exhaust vent termination in
the default configuration (venting out of the top). Note
that some local codes may require a higher vertical
vent height, extending above any perimeter fencing,
etc. In installations where the appearance of the vent is
objectionable, the low profile vent terminals in Table 6
may be used.
Combustion air inlets consist of appropriately sized
OUTDOOR VENT OUTDOOR
UNIT SIZE TERMINAL COMBUSTION
AIR TERMINAL
500 20254703 D2007900
750 20254705 D2007900
1000 20254705 D2008000
1250 D2007700 D2008000
1500 D2007700 D2008000
1750 D2007800 D2008000
2000 D2007800 D2008200
Table 6. Vent Terminals for Outdoor Units.