Rheem 199,000 Btu/hr, Руководство пользователя, Страница: 19 / 80

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INSTALLATION
TANKLESS WATER HEATER 199
For 3" Flexible PPs, up to 35 actual lineal feet are allowed in a nominally vertical
orientation (>45°). The equivalent length of 3" Flexible PPs is calculated using
a multiple of 1.4:1, e.g. 35' x 1.4 = 49' equivalent. The balance of the venting
allowance is still available for use with rigid PPs piping material.
2" Flexible PPs is not allowed.
EXHAUST PIPE SIZE/FITTINGS MAXIMUM EQUIVALENT LENGTH
Schedule 40 PVC, CPVC or PPs – Allowances are for each side separately.
2"
65' 65'
*
3" 120'
2" or 3" 90° Long Sweep Vent Elbow
Allow 5 equivalent feet
2" or 3" 90° Short Sweep Vent Elbow
Allow 8 equivalent feet
2" or 3" 45° Vent Elbow
Allow 3 equivalent feet
PPS
PPs 87-90° Elbow
Allow 8 equivalent feet
Flex PPS
2" PPs Flex Not Allowed
3" PPs Flex
35' Actual (Equivalent = Actual x 1.4)
Table 3: Maximum Exhaust Venting Length
* The input rate will derate as vent length increases. See table below for
approximate derate at 2" maximum vent length.
MAXIMUM FIRING RATE APPROXIMATE DERATE
199,000 10 - 16% 10 - 16%
Follow all installation instructions supplied by the pipe and fitting
manufacturer. Prior to assembly, ensure all venting components are clean of
burrs/debris which could clog the fan, burner, and heat exchanger.
General Venting/Piping Requirements
If the vent length requires increasing the vent pipe size to 3", the transition from
the 2" vent connector to 3" venting must occur within the first 18" of the top of the
unit and must be done in a vertical section to avoid pooling of condensate. Slope
exhaust venting back towards the unit with a pitch of at least 1/4" per foot. Follow
venting manufacturer pitch requirements, so condensate runs back towards the
trap. Support air intake and vent piping per local code and vent manufacturers
requirements. In the absence of support requirements, support the air intake and
vent piping at every vertical and horizontal transition as well as every 5' of run.
Begin the vent system installation at the unit and work towards the outdoor
termination. We recommend using a bird screen of 1/4" stainless steel or plastic
mesh (e.g., IPEX System 636 drain grate for CPVC systems) to guard against
foreign objects
.
BEST PRACTICES
To reduce the possibility of
expansion noise, allow a 1/4"
gap around the exhaust and
air intake piping.
NOTE
The bird screen is optional
for exhaust piping in cold
weather climates.
WARNING
Combustion air must not be
drawn from areas containing
corrosive air from swimming
pools or spas, including air
directly next to outdoor pools
and spas.
Figure 8