Bohn BFF054 User Manual

7170.2

July 2000

Replaces 7170.1

All belt drive models (except 575V) are
Underwriter’s Laboratories, Inc. listed.

Belt Drive Fluid Coolers

Belt Drive Fluid Coolers

Model BFF

Model BFF

Specification Data

Specification Data

BOHN DIRECT DRIVE FLUID COOLERS

BOHN DIRECT DRIVE FLUID COOLERS

Belt Drive Fluid Coolers

Multiple fans, carefully matched to the coil surface cover a large
percentage of the face area providing uniform air distribution.

Energy efficient, three phase 1750 RPM motors with drip-proof,
grease lubricated ball bearings. Each motor is inherently
overcurrent protected providing built-in protection against single
phasing. All motors are factory wired with leads marked and
terminated in a single weatherproof junction box on outside of
the unit casing.

Convenient access panels are provided on each fan section for
ease in maintaining fans.

Casing is constructed of heavy gauge aluminum, or galvanized
steel.

Multiple fan sections, each powered by a separate motors, are
separated by a full width baffle to prevent air bypass during fan
cycling.

Motors are positioned within unit casing for weather protection.
Adjustable base provides ease in belt tension adjustment.

Each fan is equipped with heavy duty pillow block ball bearings.
Bearings are supplied with lubrication fittings shown. Fan shafts
are polished steel, precision machined to assure smooth
operation, minimum bearing wear. Shafts are coated with a
corrosion resistant dressing.

Fan guards are constructed of heavy gauge, close meshed, steel
wire zinc plated and iridite dipped to minimize corrosion.

Selection Formulas

Design Load (in BTUH) = GPM * (Ent. Fluid Temp. — Leaving Fluid Temp.) x (Fluid Constant Table 1)

Average Fluid Temperature =

T.D. = Entering Fluid Temperature — Entering Air Temperature

Base Capacity =

1,000 x T.D. x Table 2 Factor x Table 4 Factor

Entering Fluid Temp. + Leaving Fluid Temp.

2

Design Load (in BTUH)

= MBH/˚T.D.

Capacity (Actual) = Capacity (Catalog) x 1,000 x T.D. x Table 2 Factor x Table 4 Factor

PD/F (Actual) = PD/F (Catalog) x Table 3 Factor

2

Selection Procedure

Given Conditions:

BOHN DIRECT DRIVE FLUID COOLERS

BOHN DIRECT DRIVE FLUID COOLERS

Belt Drive Unit — BFF 140˚F Entering Fluid Temp.
200 GPM 120˚F Leaving Fluid Temp.
30% Ethylene Glycol Solution 10 Ft. Water Max. P.D.
90˚F Ambient Air Sea Level

Solution:

1.

Calculate Design Load

A. Determine average fluid temperature for factor selection
in Tables 2 and 3.

Average Fluid Temp. =

B. Design Load = 200 x (140—120) x 470 = 1,880,000

2.

Calculate Base Capacity

A. Determine T.D.

T.D. = 140—90 = 50˚F

140 + 120

2

= 130˚F

Fluid Cooler Correction Factor Tables
Table 1.

B. Determine Capacity Correction from Table 2

Capacity Correction Factor = 1.032

C. Determine Altitude Correction from Table 4

Altitude Correction Factor = 1.0

D.

Base Capacity =

3. Make selection from capacity tables using given conditions.
Model BFF 096, capacity of 37.57 MBH/˚T.D. meets the
requirements with “C” circuiting.

4. Convert pressure drop of selection to design condition P.D.

6.1 x .950 = 5.8 ft. water pressure drop at design condition.

5. Calculate actual unit rating at design conditions 37.57 x 1,000
x 50 x 1.032 x 1.0 = 1,938,612 BTUH.

1,880,000

1,000 x 50 x 1.032 x 1.0

= 36.43

Table 4. Altitude Correction Factors

% Fluid

Glycol Constant

0 500

Fluid 20 480

Constants 30 470

40 450
50 433

Table 2.

% Average Fluid Temp. (˚F)

Glycol 90 100 110 120 130 140

0 1.079 1.081 1.083 1.086 1.090 1.095

Capacity 20 1.030 1.035 1.042 1.047 1.054 1.058

Correction 30 1.005 1.009 1.012 1.023 1.032 1.034

Factor 40 .928 .943 .960 .984 1.000 1.010

50 .918 .926 .935 .939 .941 .973

Table 3.

% Average Fluid Temp. (˚F)

Glycol 90 100 110 120 130 140

0 .868 .853 .843 .819 .795 .789

Pressure 20 .980 .959 .935 .915 .893 .866

Drop 30 1.055 1.025 1.000 .975 .950 .923

Correction 40 1.120 1.080 1.060 1.034 1.000 .974

50 1.200 1.165 1.128 1.093 1.058 1.024

For average fluid temperatures below 90˚F or above 140˚F, contact the
factory for special application.

Altitude

(Feet) Factor

0 1.000

500 0.993
1000 0.986
1500 0.974
2000 0.963
2500 0.953
3000 0.944
3500 0.935
4000 0.927
4500 0.919
5000 0.911
5500 0.903
6000 0.895
6500 0.887
7000 0.880

3

BOHN DIRECT DRIVE FLUID COOLERS

BOHN DIRECT DRIVE FLUID COOLERS

Capacity Ratings Belt Drive Fluid Coolers

Table 5A. MBH/˚T.D. — 40% Glycol — Average Fluid Temperature 130˚F (Sizes 045 - 062)

GPM
BFF Conn. Coil 30 40 50 60 70 80 90 100
Size Loc. Circ. MBH PDF MBH PDF MBH PDF MBH PDF MBH PDF MBH PDF MBH PDF MBH PDF

SE A 10.90 3.3 13.11 5.4 14.57 8.0 15.82 11.0 16.82 14.3 17.64 18.1

045 SE B 13.99 2.9 15.31 3.9 16.10 5.2 16.92 6.5 17.61 8.0 18.20 9.6

OE C 16.46 2.8 17.21 3.5 17.51 4.2
SE A 11.40 3.3 13.93 5.4 15.65 8.0 17.14 11.0 18.34 14.4 19.34 18.2

050 SE B 14.97 2.9 16.54 4.0 17.49 5.2 18.48 6.5 19.32 8.0 20.04 9.7

OE C 17.92 2.8 18.83 3.5 19.20 4.2
SE A 11.67 3.3 14.35 5.4 16.47 8.0 17.83 11.0 19.15 14.4 20.23 18.2

054 SE B 15.49 2.9 17.18 4.0 18.56 5.2 19.29 6.5 20.21 8.0 20.99 9.7

OE C 18.68 2.8 19.67 3.5 20.08 4.2
SE A 11.60 3.3 14.30 5.4 16.46 8.0 17.90 11.0 19.30 14.4 20.47 18.2

057 SE B 15.50 2.9 17.25 4.0 18.70 5.2 19.52 6.6 20.51 8.1 21.38 9.7

OE C 18.90 2.8 19.96 3.5 20.43 4.2
SE A 14.89 3.4 17.24 5.1 19.11 7.0 20.27 9.2 21.44 11.6 22.40 14.2 23.21 17.1

059 SE B 19.35 2.9 20.61 3.7 21.65 4.5 22.13 5.4

OE C 21.61 2.7
SE A 11.92 3.3 14.83 5.4 17.22 8.0 18.83 11.0 20.40 14.5 21.73 18.3

062 SE B 16.17 2.9 18.11 4.0 19.74 5.2 20.66 6.6 21.78 8.1 22.76 9.7

OE C 19.96 2.8 21.16 3.5 21.69 4.2

GPM
BFF Conn. Coil 120 140 160 180 200 250 300 350
Size Loc. Circ. MBH PDF MBH PDF MBH PDF MBH PDF MBH PDF MBH PDF MBH PDF MBH PDF

045 SE B 19.14 13.3 19.86 17.4 20.43 22.0

OE C 18.48 5.7 19.24 7.5 19.85 9.5 20.34 11.7 20.75 14.1 21.53 20.9

050 SE B 21.19 13.3 22.08 17.4 22.79 22.0

OE C 20.39 5.8 21.32 7.6 22.06 9.5 22.68 11.7 23.19 14.1 24.16 20.9

054 SE B 22.25 13.3 23.22 17.4 23.99 22.0

OE C 21.37 5.8 22.38 7.6 23.20 9.6 23.86 11.8 24.42 14.1 25.47 20.9

057 SE B 22.80 13.3 23.91 17.5 24.82 22.1

OE C 21.87 5.8 23.01 7.6 23.94 9.6 24.72 11.8 25.38 14.2 26.65 20.9

059 SE B 23.45 7.5 24.46 9.8 25.24 12.4 25.87 15.2

OE C 23.06 3.7 23.72 4.8 24.54 6.1 25.21 7.4 25.76 9.0 26.79 13.2

062 SE B 24.38 13.3 25.66 17.5 26.70 22.1

Connection Locations: SE = Same End

OE C 23.31 5.8 24.62 7.6 25.69 9.6 26.58 11.8 27.34 14.2 28.80 21.0

OE = Opposite End

4