C O M P A C T D E S I G N

S I Z E & P E R F O R M A N C E F L E X I B I L I T Y

I N T E G R A L F I N N E D T U B E S

Z E R O C R O S S C O N T A M I N A T I O N

HEAT PIPE HEAT EXCHANGER

DES CHAMPS Heat Exchangers and Energy Recovery Systems

Sensible Air-to-Air Energy Exchangers

Single Units500 – 40,000 SCFM

Multiple Units40,000+ SCFM

TABLE OF CONTENTS

Introduction ......................................................................................................................1

Model Nomenclature........................................................................................................2

Application Features ........................................................................................................3

Construction Features ......................................................................................................6

Application Considerations ............................................................................................8

Psychrometric Data ........................................................................................................10

Selection Procedure ........................................................................................................11

Heat Exchanger Performance ......................................................................................12

Dimensional Data ..........................................................................................................13

Specifications ..................................................................................................................14

I N T R O D U C T I O N

The Des Champs heat pipe heat exchanger

provides sensible heat transfer between two

airstreams using a counterflow configuration to

maximize heat transfer and minimize pressure

drop. The device contains rows of finned tubes

partially filled with refrigerant and permanently

sealed. Heating one side of a heat pipe establishes

a continuous process within it whereby the

warmer side acts as an evaporator and the colder

side a condenser. A sealed center partition pre-

vents cross contamination of the two airstreams.

A sensible heat transfer from the hot to the cold

airstream results.

2

M O D E L N O M E N C L A T U R E

HEAT P IPE HEAT EXCHANGER

MODEL NUMBER: F H P - 0 7 - 0 1 6 - 0 9 6 - 0 4 8 - A - CDIGIT: 1, 2, 3 - 4, 5 - 6, 7, 8 - 9, 10, 11 - 12, 13, 14 - 15 - 16

Digits 1, 2 and 3: Unit DesignatorFHP = Finned Heat Pipe Heat Exchanger

Digit 4,5: Number of rows in heat exchanger

Digits 6,7,8: Number of tubes in the face of heat exchanger

Digit 9,10,11: Heat pipe tube length in inches

Digit 12,13,14: Heat pipe exhaust side tube length in inches

OPTIONAL EQUIPMENT

Digit 15: Casing materialA = Aluminum B = Galvannealed C = Stainless Steel

3

A P P L I C A T I O N F E A T U R E S

ALLOWS OUTDOOR AIR DESIGN PROBLEMS TO BE SOLVED

• Responsibly Allows Codes to be MetUse of Des Champs heat pipe heat exchangers allows the designer to meet ASHRAE Standard 62-1989 ventilation requirements with minimum energy requirements

• Reduces Heating RequirementsThe size of the heating plant, air distribution system, and energy distribution system can be reduced by the amount of energy recovered

• Reduces Cooling RequirementsCompressors, chillers, cooling towers, pumps, and piping can be reduced by the amount of energytransferred between the outside and exhaust airstreams

• Solves Existing Indoor Air Quality (IAQ) ProblemsEconomically permits the introduction of additional ventilation air without overloading HVAC system

4

A P P L I C A T I O N F E A T U R E S

EASY TO SELECT AND APPLY

• CompactnessThe eight-row heat pipe heat exchanger is only 17 inchesdeep in direction of airflow. Compact design allows morespace for other equipment in crowded mechanical rooms.

• Size FlexibilityBy varying the lengths of the heat pipes, the number ofrows, and the number of tubes in the face of the heatexchanger, a unit can be designed to fit any location andmeet any performance requirement.

• Retrofit CapabilitiesThe complete size flexibility of the heat pipe heatexchanger makes replacement of heat transfer wheels inexisting systems easy.

LOW MAINTENANCE, LOW ENERGY CONSUMPTION

• Maintenance-FreeThere is no maintenance required under normal HVACconditions, because heat pipe heat exchangers have nomoving parts. In addition, they are also easier to cleanthan other types of heat exchangers.

• Passive Energy RecoveryHeat pipe heat exchangers require no external power for operation.

O P T I O N S

• Aluminum or Stainless Steel CasingFor use in corrosive environments. Contact the factoryfor specific applications.

• Anticorrosion CoatingA carboline coating suitable for most corrosive applications is available. Contact the factory for specificapplications.

• Face and Bypass DampersThis temperature control option will provide supply airtemperature regulation as well as frost protection.Unfortunately, when used in Northern climates for frostprotection, as much as half the potentially recoverableheat is wasted.

• Tilt Control PackageThe air temperature can be controlled with great preci-sion by tilting the heat exchanger, which reduces orincreases the amount of refrigerant in the evaporatorsection of the heat pipes. The tilt package comes com-plete with actuator and controls for full operation andcontrol of exhaust air temperature to prevent freezingwithin the heat exchanger and supply air temperaturefor seasonal changes.

• Indirect Evaporative CoolingSummer energy recovery can be enhanced by theinstallation of a direct spray indirect evaporative cool-ing system on the return air side of the heat pipe heatexchanger.

5

C O N S T R U C T I O N F E A T U R E S

• Integral Fin DesignEach heat pipe is fabricated using a single piece of aluminum to eliminate the possibility of fin andtube separation and to maximize heat transfer.This design technique also prevents corrosion orcontamination between fin and tube, and creates a smooth surface for the application of optionalanticorrosive coatings. Integral fin construction isvery durable and withstands high pressure air orwater cleaning.

• Individual Heat PipesThis means greater reliability in performance,since failure of one heat pipe has little effect onthe overall performance of the heat exchanger.

• Heat Exchanger Casing The heat exchanger frame is fabricated using 14-gauge galvannealed steel as shown in thedimensional data section.

• Sealed Center Partition The partition is fabricated using 16-gauge gal-vannealed steel. It is provided to prevent crosscontamination between the two airstreams and can be placed in any position to accommodateunbalanced flow systems.

• End CoversEnd covers are fabricated using 16-gauge galvan-nealed steel to protect the individual heat pipes.

• RefrigerantR-22 is utilized as the standard working fluid inHVAC applications, however, other fluids may beutilized for specialized applications (contact thefactory).

6

C O N S T R U C T I O N F E A T U R E S

• Counterflow DesignThe counterflow configuration allows Des Champsheat pipe heat exchangers to recover up to 90%of exhausted energy under ideal conditions.However, the most economical heat recovery system performance of installed units is between60 and 70%.

• Performance FlexibilityA large selection of row depths and face areas are available for required energy recovery performance.

• Quality AssuranceEach heat exchanger manufactured by Des Champs is subjected to a rigorous qualityassurance process to ensure structural integrityand conformance with design requirements.

• Lower Installation CostBy utilizing the simplest airflow configuration,counterflow, there is typically less ductworkrequired to install a heat pipe heat exchanger ascompared to a plate type heat exchanger of equalcapacity.

7

CUT-AWAY VIEW OF HEAT P IPE

A P P L I C A T I O N C O N S I D E R A T I O N S

COUNTERFLOW DESIGNHaving a counterflow design means the exhaust and supply airstreams flow in oppositedirections through separate sides of the heat exchanger.

LEVELING EXCHANGER Heat pipe heat exchangers are installed with 1/4 inch per ft. tilt angle exhaust end down,when used for heating or ventilating only, and within an 1/8 inch level end-to-end, whenused for heating, ventilating, and air conditioning.

VERTICAL INSTALLATIONVertical installation of the heat pipe exchanger is possible if the evaporator (warmer air)region is on the bottom, and the condenser (cooler air) region is on top.

MULTIPLE UNIT CONFIGURATIONSFor larger airflow applications or where space limitations exist, it may be desirable toinstall two or more heat pipe heat exchangers in series or in parallel.

SUPPORTING STRUCTUREThe exchangers should be secured rigidly so as not to allow more than 1/8 inch total bowend-to-end.

DUCT DESIGNThe exchanger is manufactured with a center partition and frame such that standard ductflanges can be screwed to the frame, using 3/8 inch length sheet metal screws. The ductdesign should be in accordance with good practice in establishing a uniform airflow acrossentire coil surface.

FILTRATION REQUIREMENTSPerformance specifications are based upon clean air and a clean heat transfer surface. It isrequired that adequate filtration be utilized in both exchanger airstreams to insure optimumperformance and minimum maintenance.

ACCESS DOORSAccess doors should be provided to allow periodic inspection of the exchanger and to facil-itate cleaning when necessary.

DRAIN PANSDrain pans are recommended under the entire exchanger both as a condensate collectionsystem and for cleaning purposes.

TEMPERATURE L IMITATIONS The heat pipe heat exchanger is a commercial product, designed to be operated at tempera-tures of 125°F and below. If the hot airstream is expected to exceed 125º F, consult the fac-tory for selection of the proper working fluid.

CODE REQUIREMENTSInstallation of the exchanger should conform to all codes, laws, and regulations applying atthe job site.

8

I N S T A L L A T I O N C O N S I D E R A T I O N S

9

CONNECTION TO OTHER AIRHANDLING UNIT SECTIONSThe heat pipe heat exchangercasing is best connected to theduct work by means of flanges.

INSTALLATION IN A PACKAGED SYSTEMThe heat pipe heat exchanger isinstalled directly on the floor.Sheet metal safe-offs direct theairflow through the heatexchanger.

P S Y C H R O M E T R I C D A T A

The heat pipe heat exchanger is a sensible heat recovery device. This means latentheat is not exchanged between the supply and exhaust airstreams, and therefore nomoisture is transferred. However, if the exhaust airstream is cooled below its dewpoint, condensation occurs and some latent energy is transferred. Condensation canthus increase the heat transfer rate and enhance sensible effectiveness, since eachpound of condensed moisture transfers about 1050 Btu to the supply airstream.

The price for this “enhanced” effectiveness comes in the form of increasing pressuredrops due to the condensate as well as frosting of the exhaust side in the winter.Therefore, any gains in effectiveness will be offset if frosting is not controlled inthe winter.

Figure 1 shows a typical sensible heat recovery process.

10

The figure above shows various operating conditions based upon 70% efficiency.

FIGURE 1

35 45 55 65 75 85 95 105 11535

90%

70%

50%

30%

OUTDOOR AIR SUMMER

B A

C D

GHE

F

EXHAUST AIR SUMMER

DRY BULB TEMPERATURE (DEGREES F)

EXHAUST AIR WINTER

OUTDOOR AIR WINTER10% RELATIVE HUMIDITY

SENSIBLE HEAT TRANSFERHEAT P IPEIn summer, the warmer airstream(outside air) is cooled from point Ato B, while the colder airstream(exhaust air) is being heated fromC to D. In winter, the process isreversed. The colder outside air isheated from E to F and the warmerindoor air is cooled from G to H.

11

S E L E C T I O N P R O C E D U R E

DEFINIT IONSFA = Total Face Area (in2)DFV = Design Face Velocity per sideQS = Supply Airflow (CFM, ft3/min)QE = Exhaust Airflow (CFM, ft3/min)TF = Tubes in Face of Heat PipeFH = Finned Height (inches)FL = Finned Length (inches)EL = Finned Length–Exhaust Side (inches)E = Effectiveness (%)TOA = outside air inlet temperature (°F)TSA = supply air outlet temperature (°F)TRA = return air inlet temperature (°F)

SCFMOA = outside air standard CFMSCFMMIN = lesser of exhaust air or outdoor air standard CFM

Step 1 Determine design face velocity per side, DFV, typically 300 to 600 fpm (feet per min).

Step 2 Determine required face area for both airflows (in2): FA = 144 x (QS + QE)/DFV

Step 3 Select the number of tubes in the face (TF) of the heat pipe to match an acceptable fin height (FH). FH = 2.125 x TF [Up to 28 tubes per exchanger*]

Step 4 Determine the required finned tube length (FL) based on the face area from Step 2.FL = FA/FH [Round to the nearest inch.]

Step 5 Calculate position of center divider. For balanced flows, this will be at the center ofthe finned length. For unbalanced flows, this location can be changed to balance thepressure loss. This will ensure that the individual airflow velocity is close to thedesign. For equal DFV on supply and exhaust sides: EL = FL x (QE/(QS + QE))[Round to the nearest inch.]

Step 6 Select heat pipe rows required in direction of airflow using Figures 2 and 3 to achieve the required thermal effectiveness and pressure drop.

Step 7 See dimensional data on page 13 for weight and overall dimensions of selected heat exchanger.

Step 8 Determine leaving supply temperature. The effectiveness (see Figure 2, page 12) isdefined as: E = (SCFMOA/SCFMMIN) x (TOA - TSA)/(TOA - TRA) x 100%See heat exchanger selection example on page 12 for temperature calculation.

*Each heat pipe heat exchanger can have up to a maximum of 28 tubes in the face. For larger airflows, it is necessary to combine multiple exchangers with 28 tubes or less per bank. Each individual bank will have its own casing according to the data in the dimensional section.

12

330

350

400

450

500

550

600

650

700

750

800

70

60

50

40

30

20

10

0

F A C E V E L O C I T Y ( F E E T P E R M I N U T E )

EF

FE

CT

IVE

NE

SS

, %

330

350

400

450

500

550

600

650

700

750

800

2.00

1.80

1.60

1.40

1.20

1.00

0.80

0.60

0.40

0.20

0.00

F A C E V E L O C I T Y ( F E E T P E R M I N U T E )

AIR

PR

ES

SU

RE

DR

OP

, IN

. W

.C.

H E AT E X C H A N G E R P E R F O R M A N C E

FIGURE 2

FIGURE 3

HEAT PIPE AIRFLOWS (CFM)FIN # OF FIN TUBE LENGTH IN INCHES

HEIGHT TUBES(INCHES) IN FACE 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192 204 216 228 240

14 7/8 7 620 930 1,240 1,549 1,859 2,169 2,479 2,789 3,099 3,409 3,719 4,029 4,339 4,648 4,958 5,268 5,578 5,888 6,198

21 1/4 10 885 1,328 1,771 2,214 2,656 3,099 3,542 3,984 4,427 4,870 5,313 5,755 6,198 6,641 7,083 7,526 7,969 8,411 8,854

27 5/8 13 1,151 1,727 2,302 2,878 3,453 4,029 4,604 5,180 5,755 6,331 6,906 7,482 8,057 8,633 9,208 9,784 10,359 10,935 11,510

34 16 1,417 2,125 2,833 3,542 4,250 4,958 5,667 6,375 7,083 7,792 8,500 9,208 9,917 10,625 11,333 12,042 12,750 13,458 14,167

40 3/8 19 1,682 2,523 3,365 4,206 5,047 5,888 6,729 7,570 8,411 9,253 10,094 10,935 11,776 12,617 13,458 14,299 15,141 15,982 16,823

46 3/4 22 1,948 2,922 3,896 4,870 5,844 6,818 7,792 8,766 9,740 10,714 11,688 12,661 13,635 14,609 15,583 16,557 17,531 18,505 19,479

53 1/8 25 2,214 3,320 4,427 5,534 6,641 7,747 8,854 9,961 11,068 12,174 13,281 14,388 15,495 16,602 17,708 18,815 19,922 21,029 22,135

59 1/2 28 2,479 3,719 4,958 6,198 7,438 8,677 9,917 11,156 12,396 13,635 14,875 16,115 17,354 18,594 19,833 21,073 22,313 23,552 24,792

Note: Airflows are for one side of the heat exchanger in an equal flow arrangement, and are based on a face velocity of 500 ft./min. Any number of tubes in the face may be selected other than those shown in the figure.

8 ROW

7 ROW

6 ROW

5 ROW

4 ROW

3 ROW

2 ROW

8 ROW7 ROW6 ROW5 ROW4 ROW

3 ROW

2 ROW

TABLE 1

HEAT EXCHANGERSELECTION EXAMPLESelect a heat pipe heat exchanger for4,000 SCFM outside air at 95°F and4,000 SCFM exhaust air at 75°F witha minimum effectiveness of 58%.

Selection:Using Figure 2, DFV = 500 fpm.

FA = 144 x (4,000 + 4,000) / 500 = 2,304 in2

For TF = 16, FH = 2.125 x 16 = 34 in.

FL = 2,304 / 34 = 67.8 in. [Round to 68]

For balanced flow, EL = 34 in. (on center)

Using Figures 2 and 3, at 500 fpm, 7 rows gives 55% effectiveness and0.86 in. w.c. pressure loss per side.From dimensional data, overall size is 74" long x 38" high x 15.25" deep,weight = 750 pounds.

To determine the leaving supply temperature:

TSA = TOA - E x (SCFMMIN/SCFMOA) x (TOA - TRA)

TSA = 95 - 0.55 x ( 4000) x (95 - 75)4000TSA = 84°F

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D I M E N S I O N A L D A T A2" FLANGE

AIR-TIGHTCENTER PARTITION

TOTAL BASE WEIGHT FOR 5 ROWS (POUNDS)FIN # OF FIN TUBE LENGTH IN INCHES

HEIGHT TUBES(INCHES) IN FACE 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192 204 216 228 240

14 7/8 7 188 235 283 330 378 425 473 520 568 615 662 710 757 805 852 900 947 995 1,042

21 1/4 10 260 322 384 447 509 572 634 697 759 822 884 947 1,009 1,071 1,134 1,196 1,259 1,321 1,384

27 5/8 13 331 409 486 563 641 718 796 873 951 1,028 1,106 1,183 1,261 1,338 1,415 1,493 1,570 1,648 1,725

34 16 403 495 588 680 772 865 957 1,050 1,142 1,235 1,327 1,420 1,512 1,605 1,697 1,790 1,882 1,974 2,067

40 3/8 19 474 582 689 797 904 1,012 1,119 1,226 1,334 1,441 1,549 1,656 1,764 1,871 1,979 2,086 2,194 2,301 2,408

46 3/4 22 546 668 791 913 1,036 1,158 1,281 1,403 1,525 1,648 1,770 1,893 2,015 2,138 2,260 2,383 2,505 2,628 2,750

53 1/8 25 617 755 892 1,030 1,167 1,305 1,442 1,580 1,717 1,855 1,992 2,129 2,267 2,404 2,542 2,679 2,817 2,954 3,092

59 1/2 28 689 841 994 1,146 1,299 1,451 1,604 1,756 1,909 2,061 2,214 2,366 2,518 2,671 2,823 2,976 3,128 3,281 3,433

HEAT PIPE DEPTHSROWS DEPTH (D) FIN DEPTH

2 5 7/8 4

3 7 3/4 5 7/8

4 9 5/8 7 3/4

5 11 1/2 9 5/8

6 13 3/8 11 1/2

7 15 1/4 13 3/8

8 17 1/8 15 1/4

TYPICAL HEAT EXCHANGER DIMENSIONSHeight (H) 14 7/8 21 1/4 27 5/8 34 40 3/8 46 3/4 53 1/8 59 1/2

Length (L) 24 36 48 60 72 84 96 108-240

WEIGHT CALCULATIONWEIGHT CORRECTION FACTORS

FINS PER ROWS DEEPINCH 2 3 4 5 6 7 811 0.49 0.66 0.83 1.00 1.19 1.38 1.56

4"

LD

L + 6

X

H H + 2X*

Note: For larger fin height or fin length require-ments, multiple exchangers may be combined.Dimensions and weights are for reference only. For design purposes, use certified data.

For heat exchanger performance selection contactthe factory or your local sales representative.

TABLE 2

TABLE 3

TABLE 5

TABLE 4

Heat Exchanger Weight (lbs) = Base Weight from Table 5 x Correction Factor

*Value of x: If L < 14', X=2"If L ≥ 14', X=3"

14

M E C H A N I C A L S P E C I F I C A T I O N S

The packaged humidity control system shall be a Model FHP ______________ asmanufactured by Des Champs Laboratories, Inc. The heat pipe shall transfer heatbetween outgoing and incoming airstreams in a counterflow arrangement, and shallbe labeled for direction of airflow, noting inlets and outlets of exhaust and supply.

The heat pipe heat exchanger shall be a passive device, requiring no rotation orother movement for heat transfer, and shall be capable of operating at temperaturesranging from -60°F minimum to 125°F maximum.

The heat pipe shall be installed: with 1/4 inch per foot tilt angle exhaust end downwhen used for heating and ventilating application only, or within 1/8 inch levelend-to-end when used for heating, ventilating, and air conditioning applications.

Performance data derived from laboratory testing on heat exchanger conditions is inaccordance with ASHRAE Standard 84-1991 “method of testing air-to-air heatexchangers.” Performance shall be rated in accordance with ARI testing procedures.

Manufacturers of alternate equipment must be approved to bid via addendum, inwriting by the specifying engineer, at least two weeks prior to bid time in order fortheir bid to be accepted by the contractor. If the equipment is not pre-approved thenunder no circumstances shall the contractor invest time or money in receiving sub-mittals or considering the equipment. Costs associated with dimensional, perfor-mance, or other deviations from the specified equipment, including engineeringcosts to evaluate such deviations, shall be paid by the contractor. The manufacturermust have a quality management system in place, equal to the quality assurancestandard ISO-9001, for the design, manufacture, and service of heat exchangers andpackaged ventilation/air conditioning equipment. The manufacturer must also havea net worth greater than five times the value of the equipment being bid and musthave been a manufacturer of air-to-air heat exchangers for at least five years priorto bid time. The air-to-air heat exchangers must be manufactured in the UnitedStates of America.

DESIGN AND CONSTRUCTION FEATURES1. Heat Pipe Heat Exchanger

Heat pipes shall have 1-inch I.D. seamless, integrally finned 3003 aluminumtubes with 0.063 inch wall thickness.

Heat pipes shall be a maximum of 2 1/8 inches on center in the face and shallbe 1 7/8 inches on center row-to-row.

Heat pipe fin surface shall be integral to the tube, and shall have a minimum of0.015 mean fin thickness, tapered root to fin tip. Fin surface from root to fin tipshall have a minimum of 0.437 inch mean fin height. Fin density shall be 11fins per inch. Two-component heat pipes such as expanded tube-to-fin shall notbe acceptable in order to prevent efficiency degradation due to eventual weaken-ing of the fin-to tube bond.

Heat pipes shall have a circumferential capillary wick structure integral to theinside of each individual tube. The capillary wick structure shall be the result ofa knurling process and shall not degrade the integrity of the heat pipe wall.

15

Heat pipes shall be individually processed, charged, hermetically sealed, andfactory tested.

Heat pipe heat exchanger shall be installed as shown on the manufacturer’ssubmittal drawings.

2. Casing

The heat exchanger frame shall be fabricated from minimum 14-gauge galvan-nealed steel. The frame shall be supplied with a minimum of 2-inch wideflanges on all four sides, both front and back. Intermediate heat pipe supportsshall be furnished as required.

The heat exchanger shall be provided with a partition to isolate the outgoingand incoming airstreams; there shall be no cross contamination. The partitionshall be fabricated from a minimum 16-gauge, galvannealed steel and shallextend beyond the finned surface with a 4-inch mid-seal (2 inches to supplyside and 2 inches to exhaust side).

End covers shall be provided to protect the heat pipe ends. End covers shall befabricated from 16-gauge galvannealed steel.

3. Refrigerant

Heat pipe heat exchanger refrigerant shall be selected on the basis of heat pipeoperating temperature and compatibility with heat pipe tube material.

Heat pipe heat exchanger refrigerant used shall be classed as group 1 in theAmerican National Standard Safety Code for Mechanical Refrigeration.

4. Temperature Controls (Optional)

The following three options are available for temperature control:

A. Face & Bypass DampersFace and bypass dampers shall be provided by Des Champs for:

a) Economizer mode

b) Regulation of supply leaving temperature

c) Frost prevention of the exhaust side of the unit.

The face and bypass damper option shall be integral to the heat exchangermodule. Dampers shall be constructed of minimum 16-gauge galvanized steeland operated by a damper motor (specify modulating or two-position) con-trolled by a thermostat (specify factory or customer provided).

B. Tilt ControlTilt control shall be provided by Des Champs for:

a) Economizer mode

b) Regulation of supply leaving temperature

c) Frost prevention of the exhaust side of the unit.

M E C H A N I C A L S P E C I F I C A T I O N S

16

The main support for the tilt control package shall consist of a heavy-duty,large diameter shaft on two heavy-duty, sealed, pillow block bearings at thecenter of the heat pipe unit. The arrangement shall be such that the heat pipecan pivot freely about the axis of the bearings.

The tilt package shall be powered by a heavy-duty drive motor and connectinglinkage.

Temperature sensors shall be placed in the supply entering and leavingairstreams, and the exhaust leaving airstreams to sense their respective temperatures.

The tilt package shall be suitable for operation at 0-10 V DC, 4-20 mA, and 0-135 W with full modulation.

The tilt package shall have flexible connectors to minimize cross-contaminationbetween airstreams, while permitting the heat pipe assembly to tilt. Customerduct connections shall be rigid.

5. Protective Coating (When Required)

Air dried carboline coating to protect against corrosion. Coating to be factoryapplied to supply and exhaust sides.

M E C H A N I C A L S P E C I F I C A T I O N S

DES CHAMPS LABORATORIES INCORPORATEDP.O. Box 220 • Douglas Way • Natural Bridge Station, VA 24579 • [540] 291-1111 • FAX [540] 291-2222

© 1998 Des Champs Laboratories Incorporated HPHE-698/10M(SUPERSEDES HPHX694)