 |
Selection Procedure |
|
Air handler unit selection and performance information
can be obtained using the Modular Climate Changer® Windows™ -based selection program.
This program allows the user to quickly configure and
select the air handling system to exactly match the
specific application requirements. The program provides the user with unit capacities, internal pressure drops, coil and
fan performance, sound data and weights. The output
data is complete with specification schedule
information and an as-built drawing for unit rough-
in dimensions and weights.
Performance for the Modular Climate Changer air handler
may also be obtained using the selection procedure
given in this section. Data for such things as pressure drops, weights and dimension
can be found in the following sections of this catalog.
Final performance and selection criteria should be obtain though the Windows Selection Program.
1
Use specified maximum coil face velocity (typically 500 fpm for cooling, 700
fpm for heating) along with unit cfm and coil type to
select unit size from the Quick Select Chart on pages
30-31.
2
Go to the Unit Data (pages 32-63), select the modules required for the system and obtain dimensions and weights for
the modules.
3
Select coils by using the Trane coil selection programs.
4
Obtain damper and filter areas from Unit Data. Use the tables in Performance
Data (pages 74-81) to obtain pressures. Include coils,
filters, dampers, plenum, face and bypass, external static pressure, etc. Sum the total static pressure for all modules for design
filter pressure drop, Trane recommends finding a
pressure drop that is halfway between clean and dirty
conditions. This is done to limit cfm fluctuation from design conditions as filters load up.
5
Use the design cfm and total static pressure to choose a fan from the fan curves in the catalog supplements, CLCH-CS-7A,
7B and 7C; or use the selection program.
6
Determine the fan brake horsepower and rpm and motor horsepower. (Account
for belt and drive losses by adding 2 to 6 percent to
the brake horsepower.)
Selection Example
Specified Conditions
Horizontal draw-thru configuration, 1 /2 ’’
tube coils, single wall construction, VAV application
scfm = 7,000
external sp = 1.85 in wg.
max cooling face velocity = 500 fpm
Summer Design
coil entering air temperature = 80 F DB/67 F WB
coil leaving air temperature = 55 F DB/54 F WB
entering chilled water temperature = 45 F
water temperature rise = 10
F
Winter Design
coil entering air temperature = 60 F coil leaving air temperature = 90 F entering water temperature = 200 F water
temperature drop = 20 F
Procedure
1
Using a 1 /2 ’’ Unit Coil at 500 fpm to enter the Quick Select Chart on page 30 returns the following:
Size 12 = 6150 cfm and Size 14 = 7100 cfm. Design cfm = 7000
Select Size 14.
2
Select modules and obtain dimension and weights from pages 42 through 43
Mixing Box Module:
L = 34 inches
H = 40 inches
W = 68 inches
Wt. = 415 lbs.
Angled Filter Module:
L = 24 1 /2 inches
H = 40 inches
W = 68 inches
Wt. = 211 lbs.
Small Horizontal Coil Module:
L = 11 inches
H = 40 inches
W = 68 inches
Wt. = 105 lbs.
Medium Access Module:
L = 15 1 /2 inches
H = 40 inches
W = 68 inches
Wt. = 118 lbs.
Medium Horizontal Coil Module:
L = 15 1 /2 inches
H = 40 inches
W = 68 inches
Wt. = 125 lbs.
Horizontal Fan Module (BI Fan):
L = 40 inches
H = 40 inches
W = 68 inches
Wt. = 915 lbs.
3
Select cooling coil.
6-row type UW coil with 114 fpf and no turbulators, weight is 297 lbs. and APD = .68 Inches wg
Select heating coil. 2-row type UW coil with 72 fpf and
no turbulators, weight is 111 lbs. and APD = .18 inches wg
4
Sum static pressures: Mixing
Box Dampers: (7.04 ft 2) 05 Angled Filter Module: (26.7
ft 2 ) .54 Small Horizontal Coil Module: 18 Medium Horizontal Coil Module: .68 External Static Pressures: 1.85 TOTAL
= 3.30
5
Refer to CLCH-CS-7A to find the appropriate fan curve/rpm table. The selected
unit has a horizontal discharge and inlet vanes. There
are two fan wheel options available in this unit size.
Using the recommendations given in the applications section, select the B fan.
6
Determine the fan brake horsepower and rpm and motor horsepower. bhp
= 6.01 x 1.03 = 6.19 rpm = 1110 |
