Bohn H-IM-AH Installation Manual

Bulletin No� H-IM-AH August 2002 Part Number 4346B001

(Replaces H-IM-71A, August 2002)

Installation &

Operations Manual

Air Handler Unit

Table of Contents

Inspection ��2 Shipment of Units Handling Suspended Units Installation Motors & Drives Steam Coils Steam Coils ��3 Water Coils Direct Expansion Coils Start-up ��4 Maintenance Condensate Drain Traps Internal Isolation Section Assembly ��5 Coil Stacking Freezing Temperatures ��6 Weights ��7 Shipment of Sections Filter Quantities ��8 Replacement Parts

Installation and Operations Manual

Inspection

Shipment should be checked against the bill of lading to verify that all items listed have been received� All parts should be carefully inspected to determine if any damage was incurred in shipment�

Any shortage and/or claims for damage should be immediately reported to the delivering carrier, followed by ling a claim for shortages and/or damages�

Shipment of Units

Depending on the unit size and accessories included, the shipment may be in two or more sections�

Handling

Special care should be taken when handling and assembling component sections of the unit� Rough handling at the jobsite can result in damaged bearings, bent shafts, etc�

All units are shipped on wooden skids� It is recommended that units not be moved removed from skids until they are at a place of installation� The mounting legs/rails provided for isolators should be used when lifting units into place�

Suspended Units

Sizes 03 through 41 may be ceiling-suspended from the mounting legs/based rails with 5/8” diameter rods (not furnished)� These rods will pass through the 11/16” diameter mounting holes provided� Sizes 50, 65 and 75 cannot be ceiling-suspended�

Installation

It is very important that the unit be installed in a level position to prevent distortion and to ensure proper damper operation and coil drainage�

Allow sucient space around the unit for proper maintenance� Consider factors such as lter removal for cleaning or replacement, access to all removal panels, removal of coils and shaft if necessary, lubrication access or motor belt adjustment� Canvas duct connections should be used between the unit and supply and return air ducts�

Units are furnished with 1-1/4” FPT drain connection on each side of the coil section� The drain line from the drain pan connection must be adequately pitched and should have a water seal of sucient depth to compensate for the air pressure within the units� (See Condensate Drain Traps on page 4�)

When the unit is located on the roof, it must be mounted on support beams that span load-bearing walls� If not, excessive vibration may occur because of the resiliency of the roof�

2 Part # 4346B001

Fan noise is a function of fan design, volume ow, pressure and fan eciency and could be loud enough to disturb those in occupied areas� Therefore, on critical applications we recommend extra sound attention�

Motors and Drives

All units will normally be shipped with motor and drive installed� When mounting a motor on the adjustable base (installed on the unit), extreme care should be taken to ensure proper alignment and belt tension� All electrical work should be done in strict accordance with local codes and regulations�

Steam Coils

Type J and NFS coils have supply and return connections on the same end� Types R, S and RA coils have supply and return connections on opposite ends� Type NFD coils have supply connections on each end of the coil, with a single return connection on one end only�

All piping should be in accordance with accepted industry standards and local codes� Support all piping independent of coil and provide adequate swing joints in all piping to absorb expansion and contraction strains�

Run return piping the full size of the coil return connection from the coil to a dirt pocket� (Do not use reducing ttings�) Install drip traps in steam mains ahead of coils� Do not drip steam mains through the coils�

Install a vacuum breaker (1/2” 15º check valve) ahead of the trap on low-pressure, open-gravity return systems and on high pressure systems� Install a 1/2” 15º swing check valve in a 1/2” vacuum-equalizing line, bypassing the condensate trap, on low pressure vacuum systems�

When two or more steam coils are furnished in a unit, provide separate traps for each coil� Size traps with ample capacity using the maximum heating load and service factor recommended by the trap manufacturer�

Select control valves in accordance with the recommendations of the control manufacturer using actual heating loads�

Install suitable strainer ahead of all automatic valves and traps to catch dirt and scale� Provide adequate air vents to expel air and other non-condensable material�

Control valves used for type J, NFS, RA and NFD coils must be gradual-acting, modulating type with veeport�

Where a control valve is used for type S or R coils and the entering air temperature is below 35ºF, use a twoposition valve� Locate control element in the entering air

Air Handler Units

stream so that valve will remain open with a minimum of ve pounds steam pressure when the entering air temperature is below 35ºF� At system start-up, the damper should remain closed for approximately ten minutes after the steam valve is opened�

Properly locate all temperature sensing elements at a point of true average air mixture temperature� Refer to Diagrams 1 and 2 for controls positioning and piping conguration�

When face and bypass dampers are used, it is good practice to install a valve that closes with the face damper to prevent overheating because of damper leakage or heat from the exposed coil face�

Diagram 1� Typical Steam Coil Piping

Low Pressure, Open Gravity Return System

Steam Main

Water Piping

All piping must be supported independent of coils� Swing joints or exible ttings must be provided to absorb expansion and contraction strains� Rigid piping may also reduce eectiveness of vibration isolators�

The water supply should always be connected to the bottom inlet of the coil� The coil connections are identied with stickers�

Water coils (3 through 10 rows) are supplied with a vent and drain connection (1/4” MPT) that extends through the unit casing� Coils must be adequately vented in order to prevent air binding� For protection of coils exposed to freezing temperatures, refer to page 6�

Direct Expansion

Both the liquid distributor and the suction line extend through the casting� The expansion valve utilized must be the external equalizer tube type� The expansion valve bulb must be placed on the suction line between the coil and the 1/4” external equalizer tube� Never put the bulb in a trap�

Gate Valve

Strainer

Control Valve

Union

Vacuum Breaker 1/2”-15” Check Valve

Vent

Gate Valve

12” Minimum

Union

Strainer

Dirt Pocket

Union

Combination Float

and

Thermostatic Trap

Return Main

Diagram 2� Typical Steam Coil Piping

High Pressure System

Gate Valve

Strainer

Control Valve

Union

Vacuum Breaker

Vent

1/2”-15” Check Valve

Open Vent

Steam Main

All refrigerant piping practices should be in accordance with local codes and latest ANSI Standard B9 Safety Code� Hard-drawn type L or K copper tubing should be used� Soft tubing may be used where bending is required, provided it is in accordance with local codes�

Remember to check for adequate vacuum, clear tubes of foreign material, etc�

Gate Valve

12” Minimum

Union

Strainer

Dirt Pocket

Union

Float or

Bucket Trap

Return Main

Air Handler Unit Installation & Operations Manual, August 2002 3

Condensate Drain Trap

Installation and Operations Manual

Start-Up

Make sure all bolts and screws are tight� Remove tagged shipping tie-down bolts and spacers from the fan and motor assembly before start-up on internally isolated units only�

Check the alignment of the sheaves and tighten the set screws� Make sure that the dimension across the top is equal on all grooves, otherwise excessive belt wear will result�

Check for proper rotation of the blower pulley� Threephase motor rotation can be reversed by exchanging two of the three leads at the motor starter� The rotation of single-phase motors can be reversed by exchanging leads inside the motor junction box� (See motor wiring diagram�)

Check the amperage draw of the motor; should not exceed the nameplate amps shown on the motor serial plate�

After approximately two weeks of operation, the belts will have almost reached their permanent stretch� At this point, the belt tension should be checked again and proper adjustment made�

Maintenance

The belt tension should be checked at threemonth intervals� The fan shaft bearings on sizes 03, 06, 08, 10 and 12 are lifetime-lubricated� All other units have ball bearings that can be re-lubricated�

Bearings mounted inside the fan section have extended lubrication lines on the outside of the fan panels� The suggested greasing intervals are indicated on a sticker on the unit� It is recommended that bearings are lubricated with a high quality lithium grease as indicated on the sticker� Instructions are included on the motor nameplate for lubricating the motor bearings�

The lter should be periodically inspected and replaced or cleaned when necessary� Dirty lters inhibit air ow, reducing the capacity of the system�

Condensate Drain Traps

The condensate drain trap piping must be properly designed to ensure the removal of condensate� Incorrect trapping can hold water, causing overow in the drain pan� On blow-thru units with incorrect trapping, system air can be lost down the drain�

Figure 1�

(Air Seal)

1-1/4” Pipe Drain

(a) On draw-thru units (A) shall be equal to or greater the coil section’s negative pressure at operating conditions

(b) On blow-thru units (A) can be as small as 1” but (B) must equal or exceed the total static pressure in the coil section

Internally Isolated Units

Sizes 03-41 with optional internal spring isolation have four hold-down shipping braces� Remove the 1/2” bolt between each shipping brace and the motor base, then loosen the bolt between the frame and brace and slide the brace 5/8” from the motor support base� Re-tighten the bolt so the shipping brace acts as a snubber on fan start-up�

Figure 2�

Do not operate system without lters�

4 Part # 4346B001

Air Handler Units

Typical ‘Accessory-to-Coil-Section’

and ‘Accessory-to-Accessory’ Attachment

Figure 3�

Figure 4� Figure 5�

Air Handler Unit Installation & Operations Manual, August 2002 5

Installation and Operations Manual

Protecting Water Coils Exposed to Freezing Temperatures

Water coils exposed to freezing temperatures must be protected by properly draining the coils or adding antifreeze solution to coils�

The coils are circuited so there are no trapped circuits� However, because of the serpentine nature of the circuiting, it is almost impossible to adequately drain the coils with gravity alone� On longer coils, a fraction of a degree deviation from a horizontal plane can lead to trapped water within the circuits�

Water that failed to drain from a single tube, or even part of a tube, can cause the tube to rupture upon freezing�

Draining Coils Using Supplemental Air Blower

Ideally, a blower capable of delivering 150 CFM of air at approximately 40-50 inches of water or more should be used� Some small air compressors, while delivering higher pressures, will not deliver sucient volume of air�

1� Drain the coils by gravity after opening the supply,

return, vent and drain connection� Tap the coil causing along the length of the coil during the draining process�

2� Connect the blower to a large connection at

the greatest elevation� The small vent or drain connection on the header that the blower is connected to should be closed� Refer to Figure 6 for typical hook-up during the blow-out operation�

Installation of Antifreeze Solution

A second way to prevent a coil freeze-up is to add an antifreeze such as glycol to the coil�

The addition of antifreeze to a system exposed to freezing conditions may be necessary if the system must be operational at a moment’s notice� Antifreeze aects the chiller and coil performance and must be taken into consideration when selecting the components�

Valve o the coil so only the coil has antifreeze added� The best way to mix the antifreeze is to make a runaround loop with a circulating pump�

1� Open all connections and drain the coil as

thoroughly as possible�

2� The antifreeze solution should be added and

circulated until the solution is thoroughly mixed and all air is purged from the coil� To accomplish this the air vent should be opened during the lling operation and cracked during the pumping operation�

3� When the solution has circulated for 15-20 minutes,

the concentration of the solution should be checked with a suitable hydrometer� If the concentration is low, add more glycol and operate the pump again� A typical piping diagram is shown in Figure 7�

4� The antifreeze solution may then be left in the

coils or drained and used to ush another coil� The concentration must be checked for each coil ushed�

Figure 7�

Figure 6�

3� Turn on the blower� The blower should be operated

until no moisture can be detected leaving the coil� Then, shut the blower o and let the coil stand for a few minutes, allowing the moisture on the walls to accumulate�

4� Then the blowing-out operation should be

repeated� Ideally, the coil should stand 24 hours and then be blown out again� Leave all connections open until coil is put into operation�

6 Part # 4346B001

Note: Most antifreeze solutions will be furnished with a concentration chart� Also, make sure the antifreeze solution is not corrosive�

Air Handler Units

Air Handler Component Weight (lbs�)

Air Handler Component Unit Size

Section

Fan and Coil

Filter

Other

Large

Model ID

HDHDHeating Duty

Section

FO FO

Section

Combination Filter & Economizer

Accessories

Coils

Description S S

L L V

High Capacity - TA & Pleated

High Capacity - Permanent High Eciency - 21” Section High Eciency - 28” Section High Eciency - 44” Section

Internal Face and Bypass

External Face and Bypass

S Auxiliary Coil Module L Auxiliary Coil Module

Short Short

Long Long

Vertical

Heating DutyFCAF

Fan Only Fan Only

Flat - TA & Pleated 2”

Flat - Permanent 2”

Flat - Pleated 4”

Economizer

Electric Heater

5/8” Tube

(Type 5)

10 FPI

Fan

FC AF

FC AF FC

FC AF

12Row

34Row

6 8

10

03 06 08 10 12 14 18 20 26 34 41 50 65 75

290-430-500-550-650-790-816-836

318

450

553

600

-

73 79 88

95

-

482

83 89

98 187 196 112 143 173 216 403

204 257 454

134 168 240 311 383

296

387

170-280-312-360-450-510-564-605

162-266-296-342-428-485-536-575

60 66 75

149

168

155

176

82

103

121

127

150

174

195

323

363

525768757987100

129

164

157

184

223

356

Row36505680701018012094143

109 141 172

106 132 187 242 297

Row6478 Row Row Row

535

95 101 110 206 216 133 170 201 224 430

110 208 258 550

161 202 290 379 467

732

-

615

99 106 119 215 225 133 170 201 236 451 115 128 223 305 670

195 246 353 461 569

(Coil weight includes the weight of water when lled)

988

860

104 114 124 224 234 153 196 230 247 471 138 155 306 504 774 106 164 223 282 408 534 659

968

1,188

946

1,177

1,033

1,067

-

1,004

106 126 126 230 240 175 225 264 254 484 148 166 280 497 954 110 169 231 292 422 552 682

1,177 1,111

715

679 108 135 127 234 244 180 224 274 260 494 155 175 261 492

1,104

112 173 236 299 432 565 699

1,221 1,430 1,254

693 891 658 846 115 165 130 244 254 194 246 299 300 544 180 200 310 563

1,434

144 228 314 398 578 760 942

1,386

1,518

1,782-2,700-3,300-4,496

1,474

1,672

1,793

2,057

1,628

1,881

902

1,078

1,221

1,474-2,600-3,200-3,359

857

1,024

1,160

1,400-2,470-3,040-3,191

160

185

240

275

185

210

260

290

365

450

235

248

296

318

358

380

430

550

690

840

260

350

286

385

331

362

617

648

1,760

2,118

195

239

318

396

444

557

569

718

830

1,052

1,092

1,385

1,355

1,718

-

2,850

-

255 390 298 360 520 269 345 412 680

1,040

420 462 515 665

2,481

339 562 737

913 1,278 1,638 2,194

-

3,480

-

315 460 351 440 650 330 425 516 800

1,240

520 650 640 820

3,143

406 673

936 1,199 1,677 2,154 2,893

-

4,690

-

384 560 428 535 790 359 463 552 975

1,510

634

793 1,305 1,499 3,599

538

891 1,168 1,445 2,017 2,589 3,478

To Estimate Weights For Other Coils

For 1/2” Tube (Type A): Multiply Type 5 coil weight by 0�800

For small coil: Multiply large coil weight by 0�823

TA = Throwaway lters

AF = Airfoil Fan

FC = Forward Curved Fan

For 14 FPI: Multiply 10 FPI coil weight by 1�121 For 12 FPI: Multiply 10 FPI coil weight by 1�065

For 8 FPI: Multiply 10 FPI coil weight by 0�935 For 6 FPI: Multiply 10 FPI coil weight by 0�915

Air Handler Motor

and Drive Weight (lbs�)

Open Single Speed Motor

Totally Enclosed Fan Cooled (TEFC)

High Eciency Open Single Speed

Open 2 Speed, 2 Winding

1 1�5-2 3 5 7�5 10 15 20 25 30 40 50 60 75

555665718688105

67717497114

115

Motor Horsepower, 1800 RPM

172

193

253

286

104

178

194

275

336

127

209

216

341

384

160

291

267

368

356

348

400

529

411

461

624

396

427-621-623--

366

600 670

T - Frame Size 143 145 182 184 213 215 254 256 284 286 324 326 364 365

Central Station Air Handler, Shipment of Assemblies - Basic Unit

Horizontal Style Units, Fan, Coil, Flat Filter Section Vertical Style Units, Fan, Coil, Flat Filter Section

S, L, FO,

HD Sizes

03 – 18

S, L, FO,

HD Sizes

20 – 75

FS

CS

These diagram show typical shipments� Some set-ups may vary

FF

with certain units� Consult the factory if you require a specic assembly shipped in a

FF

special way�

V Sizes

03 – 18

V Sizes

20 – 41

FS

CS

FS

CS

We ship high capacity and high eciency lter sections,

FF

economizers, dampers and electric heat sections separately�

FF

720-828

-

Air Handler Unit Installation & Operations Manual, August 2002 7

Quantity and Dimensions of Filters for Flat Filter Section

Filter

Dimensions 2” x 16” x 20” 2” x 20” x 20” 2” x 16” x 25” 2” x 20” x 25”

03 06 08 10 12 14 18 20 26 34 41 50 65 75

1 1

-

2

-

4

-

3 3

-

Air Handler Unit Size

1 1 2 2

2 2 2 2

6 4

-

4 8

-

4 8

12

6

-

7

-

14

-

High Capacity Filter Section

2” x 16” x 20” 2” x 20” x 20” 2” x 16” x 25” 2” x 20” x 25”

2 2

-

4

-

6

-

2 4

-

8

-

4 4

-

6 4

-

4 6

10

-

2

20

4

-

20

-

4

-

30

High Eciency Filter Section

24” x 24” 12” x 24”

1 1

2

-

2 2

2 3

3 3

6

-

4 4

5

10

5

10

-

15

5

-

Replacement Parts - Note: Conrm the shaft diameter when ordering parts

Sizes 03-12 Forward Curved,

Fan Diameter, Type

03 FC 03 FC 06 FC 06 FC 08 FC 08 FC 10 FC 10 FC 12 FC 12 FC

NOTES: For sizes 03-12, it is less expensive to replace the blower assembly than to replace the blower wheel� Blower assembly also includes bearings and shaft

9”

9” 12” 12” 15” 15” 18” 18” 18” 18”

Low Pressure

Med� Pressure

Low Pressure

Med� Pressure

Low Pressure

Med� Pressure

Low Pressure

Med� Pressure

Low Pressure

Med� Pressure

Shaft

Diameter

3/4”

1” 1”

1-3/16”

1”

1-3/16”

1”

1-3/16”

1”

1-3/16”

Bearing Part No�

4215V 4352N 4350N 4353N 4350N 4353N 4350N 4353N 4350N 4353N

Bearing

Type

Cartridge

Pillow Block

Cartridge

Pillow Block

Cartridge

Pillow Block

Cartridge

Pillow Block

Cartridge

Pillow Block

Shaft

Part No�

4317Z

4343N

4318Z

4344N

4319Z

4345N

4320Z

4346N

4320Z

4346N

8

20

-

12 30

15

3

Blower

Assembly

4317M 4322M 4318M 4323M 4319M 4324M 4320M 4325M 4320M 4325M

4

10

4

10

-

14 35

20

4

Sizes 14-41 Forward Curved,

Fan Diameter, Type

14 FC 14 FC 18 FC 18 FC 20 FC 26 FC 34 FC 41 FC

NOTES: For sizes 14-41 forward curved fans, it is less expensive to replace the blower wheel than to replace the blower assembly

20” 20” 20” 20” 22” 22” 25” 30”

Low Pressure

Med� Pressure

Low Pressure Med� Pressure Med� Pressure Med� Pressure Med� Pressure Med� Pressure

Sizes 26-75, Air Foils

Unit Size, Fan Diameter, Type

20 AF 26 AF 34 AF 41 AF 50 AF 65 AF 75 AF

18-1/4” 18-1/4” 24-1/2”

30” 32-3/8” 39-3/8” 39-3/8”

Med� Pressure Med� Pressure Med� Pressure Med� Pressure Med� Pressure Med� Pressure Med� Pressure

Shaft

Diameter

1-3/16” 1-3/16” 1-3/16” 1-3/16” 1-7/16”

1-7/16” 1-11/16” 1-15/16”

Shaft

Diameter

1-7/16” 1-7/16”

1-15/16”

2-3/16”

2-7/16” 2-11/16” 2-11/16”

Pillow Block

Bearing

4353N 4353N 4353N 4353N 5562N 5562N 5563N 5564N

Pillow Block

Bearing

5562N 5562N 5564N

5521T 5597T 5875E 5875E

Shaft

Wheel

4342N 4342N 4342N 4342N

4522R 4522R 4525R 4500S

For size 41-75 air foils and parts other than bearing replacement, call the parts department, 800-686-7278, with air handler model number

Heatcraft Refrigeration Products can then advise the correct blower assembly description for you�

Visit our website at www�heatcraftrpd�com for technical literature online�

Blower

Wheel

5154E 5154E 5154E 5154E 5153E

5153E 5179D 5178D

Part of housing Part of housing Part of housing Part of housing

Air Foil Note:

and discharge arrangement�

Blower

Cut-O

4418T 4418T 4419T 4421T

Heatcraft Refrigeration Products LLC

2175 West Park Place Blvd�, Stone Mountain, GA 30087 Ph�: 770�465�5600 • Fax: 770�465�5990 • www�heatcraftrpd�com

Rev 0407

H-IM-AH-0407 | version 000

Since product improvement is a continuing eort, we reserve the right to make changes in specications without notice�