Multiple circuits, Worksheets - multiple circuits, Multiple circuit worksheet – Bally Refrigerated Boxes BVC Generation C – Direct Drive Air-Cooled – Vertical Air User Manual
Page 27
- 27 -
WORKSHEETS - MULTIPLE CIRCUITS
1. SYSTEM DATA REQUIREMENTS
CONDENSER DESIGN AMBIENT TEMP =
(AT )
o
F
ALTITUDE
=
SEA LEVEL
or
FEET
FACTOR =
(See P. 2)
CIRCUIT INFORMATION
CIRC # 1
CIRC # 2
CIRC # 3
CIRC # 4
OPEN
HERMETIC
EVAP. TEMP
o
F =
CONDENSING TEMP =
COMPR CAP. (MBH) =
REFRIGERANT =
TD =
(Cond Temp - Amb.)
2. THR (Total Heat of Rejection) CALCULATION
COMPR CAPACITY (MBH)
X HRf
X ALTf
X REFf
= THR (MBH)
/ TD
= CL
CIRC # 1
X
X
X
=
/
=
CIRC # 2
X
X
X
=
/
=
CIRC # 3
X
X
X
=
/
=
CIRC # 4
X
X
X
=
/
=
TOTAL THR Capacity (MBH / 1
o
F TD) =
W here HR f =Heat of rejection factor (see Table 2, P. 25)
ALT f = Altitude/elevation factor (Sea level=1, see P. 2 for Higher)
REF f = Refrigerant Correction factor (R22 = 1)
R12 = 1/.95 = 1.05, R134a = 1/.94 = 1.06,
R502 = 1/.98 = 1.02, R404A / R507 / R407A/B = 1/.97 = 1.03
Alternate refrigerant based on factors from P. 2
THR = Total Heat of Rejection (MBH) to be rejected by condenser (R22 capacity)
TD = Condensing Temp - Ambient Temperature
CL = Circuit loading per 1
o
F TD
3. CONDENSER SELECTION
Refer to the R22 CAPACITY selection (P.2) and select a condenser at the 1
o
F TD that will closely match the above Total THR Capacity (MBH/ 1
o
F TD).
COND. MODEL #
For the model selected, refer to P. 2 and enter...
Max no. of Feeds
=
(A)
MBH @ 1
o
F TD per feed =
(B)
calculate the number of feeds required for each circuit.
CL (MBH / 1
o
F TD) / (B) value
= NF number of feeds required (round off to nearest whole #)
CIRC # 1
/
=
CIRC # 2
/
=
CIRC # 3
/
=
CIRC # 4
/
=
Total number of feeds required NF =
(must not exceed value (A))
If number of feeds required exceeds number of feeds available then select the next larger size
condenser model that can handle the number and repeat above process.
4. ACTUAL CONDENSING TEMP (per circuit) CALCULATION
ATD
First calculate the ATD (Actual TD) as follows:
{ THR (from sec. 2) / NF value}
/ value (B)
= (Actual Temperature Difference)
CIRC # 1
{
/
}
/
=
CIRC # 2
{
/
}
/
=
CIRC # 3
{
/
}
/
=
CIRC # 4
{
/
}
/
=
To find the Actual Condensing Temperature (ACT) just add the Actual Temperature Difference (ATD) to the design ambient (AT)
ATD
+
AT
=
ACT
CIRC # 1
+
=
o
F
CIRC # 2
+
=
o
F
CIRC # 3
+
=
o
F
CIRC # 4
+
=
o
F
NOTE: The Actual Condensing Temp. MUST EQUAL or BE LESS THAN the condensing temp recorded in section 1 above.
This ensures the compressor capacity is maintained when operating the condenser at the design ambient tremperature.
For further assistance please contact your local BALLY sales representative.
JOB REF:
MULTIPLE CIRCUIT WORKSHEET
(REFER TO P. 24 FOR GUIDELINES & SEE SAMPLE SELECTION ON P. 29)