Bosch C1210ESC - 6 Water Heater Sizing & Speci Cations; Sizing Tankless Water Heaters

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THERM/GREENTHERM Tankless Water Heaters
Bosch Thermotechnology Corp.Data subject to change
Applications Manual
6 Water Heater Sizing &
Speci cations
This section describes the water heaters available from
Bosch Thermotechnology Corp. and provides a general
overview to the speci cations of each particular model.
More detailed information is contained in the installation
manuals. Download manuals at www.bosch-climate.us.
6.1 Sizing tankless water heaters
Rule of thumb sizing
The tables below provide a general rule of thumb when
sizing for most residential applications. For commercial
applications or for a more detailed sizing method, use the
Sizing by Chart instructions below in conjunction with the
charts on the next page.
Sizing by Chart
f Measure the flow rates at each fixture that will be
used simultaneously and add them together. If only
one application will be used at a time measure each
fixture and use the maximum flow rate observed.
f Using a known volume container, record several fill
times. Perform the calculation below to determine the
flow rate (a one gallon fill time of 30 seconds is 2.0
gallons per minute (GPM):
Flow rate (GPM) =
Volume (gallons)
Fill time (sec)
sec
min
60
x
Hot water  ow rate at 120°F Set Point temperature
Model
Inlet temperature (°F)
77° 72° 67° 62° 57° 52° 47° 42° 37°
C 1210
ES /
ESC
9.8 8.8 8.0 7.3 6.7 6.2 5.8 5.4 5.1
C 1050
ES
8.5 7.6 6.9 6.3 5.8 5.4 5.0 4.7 4.4
C 950
ES
7.7 6.9 6.2 5.7 5.2 4.9 4.5 4.2 4.0
940 ES
/ ESO
7.7 6.9 6.2 5.7 5.2 4.9 4.5 4.2 4.0
830 ES
6.7 6.0 5.4 5.0 4.6 4.2 4.0 3.7 3.5
520 HN
/ PN
4.3 3.8 3.5 3.2 2.9 2.7 2.5 2.3 2.2
330 PN
2.7 2.4 2.2 2.0
1.9 1.7 1.6 1.5 1.4
Simultaneous Showers Sink Faucet
CA
OR
WA
ID
NV
MT
WY
UT
AZ
NM
CO
ND
SD
NE
TX
OK
KS
MN
IA
MO
AR
LA
MI
IN
IL
WI
GA
AL
MS
TN
KY
WV
VA
NC
SC
FL
NH
VT
NY
PA
OH
NJ
RI
CT
MA
ME
MD
DE
WA
O
R
C
A
NV
ID
UT
AZ
NM
CO
WY
MT
ND
S
D
NE
K
S
OK
TX
LA
AR
M
O
IA
MN
WI
MI
IL
IN
O
H
KY
TN
M
S
AL
G
A
FL
SC
N
C
VA
WV
PA
NY
MA
A
A
VT
NH
ME
H
˚F
77˚
72˚
67˚
62˚
57˚
52˚
47˚
42˚
37˚
Figure 2 Average ground water temperatures
f Using a thermometer, measure the incoming water
temperature. For reference, see average ground water
temperature map. Subtract this temperature from
the desired hot water temperature to get the degree
rise. If the desired hot water temperature is 120F and
incoming temperature is 55F, the desired degree rise
is 65F.
EXAMPLE:
f Required flow rate of 2.0 GPM at a 65F rise.
f Refer to the graphs on page 10.
f Since the demand is above the 330 PN capacity, this
application would require a 520 HN/PN gas tankless
water heater.