HEAT PIPE
HEAT EXCHANGER
Sensible Air-to-Air
Energy Exchangers
Single Units
500 – 40,000 SCFM
Multiple Units
40,000+ SCFM
INTEGRAL FINNED TUBES
ZERO CROSS CONTAMINATION
COMPACT DESIGN
SIZE & PERFORMANCE FLEXIBILITY
DES CHAMPS
Heat Exchangers and Energy Recovery Systems
INTRODUCTION
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 prevents cross contamination of the two airstreams.
A sensible heat transfer from the hot to the cold
airstream results.
TA B L E O F C O N T E N T S
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
MODEL NOMENCLATURE
H E AT P I P E H E AT E X C H A N G E R
MODEL NUMBER: F H P - 0 7 - 0 1 6 - 0 9 6 - 0 4 8 - A - C
D I G I T:
1, 2, 3 - 4, 5 - 6, 7, 8 - 9, 10, 11 - 12, 13, 14 - 15 - 16
Digits 1, 2 and 3: Unit Designator
FHP = 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 material
A = Aluminum
2
B = Galvannealed
C = Stainless Steel
APPLICATION FEATURES
A L L O W S O U T D O O R A I R D E S I G N P R O B L E M S TO B E S O LV E D
• Responsibly Allows Codes to be Met
Use of Des Champs heat pipe heat exchangers
allows the designer to meet ASHRAE Standard
62-1989 ventilation requirements with minimum
energy requirements
• Reduces Heating Requirements
The size of the heating plant, air distribution
system, and energy distribution system can be reduced
by the amount of energy recovered
• Reduces Cooling Requirements
Compressors, chillers, cooling towers, pumps,
and piping can be reduced by the amount of energy
transferred between the outside and exhaust airstreams
• Solves Existing Indoor Air Quality (IAQ) Problems
Economically permits the introduction of additional
ventilation air without overloading HVAC system
3
APPLICATION FEATURES
E A S Y TO S E L E C T A N D A P P LY
• Compactness
The eight-row heat pipe heat exchanger is only 17 inches
deep in direction of airflow. Compact design allows more
space for other equipment in crowded mechanical rooms.
• Size Flexibility
By varying the lengths of the heat pipes, the number of
rows, and the number of tubes in the face of the heat
exchanger, a unit can be designed to fit any location and
meet any performance requirement.
• Retrofit Capabilities
The complete size flexibility of the heat pipe heat
exchanger makes replacement of heat transfer wheels in
existing systems easy.
LOW MAINTENANCE, LOW ENERGY CONSUMPTION
• Maintenance-Free
4
There is no maintenance required under normal HVAC
conditions, because heat pipe heat exchangers have no
moving parts. In addition, they are also easier to clean
than other types of heat exchangers.
• Passive Energy Recovery
Heat pipe heat exchangers require no external power
for operation.
OPTIONS
• Aluminum or Stainless Steel Casing
For use in corrosive environments. Contact the factory
for specific applications.
• Anticorrosion Coating
A carboline coating suitable for most corrosive
applications is available. Contact the factory for specific
applications.
• Face and Bypass Dampers
This temperature control option will provide supply air
temperature regulation as well as frost protection.
Unfortunately, when used in Northern climates for frost
protection, as much as half the potentially recoverable
heat is wasted.
• Tilt Control Package
The air temperature can be controlled with great precision by tilting the heat exchanger, which reduces or
increases the amount of refrigerant in the evaporator
section of the heat pipes. The tilt package comes complete with actuator and controls for full operation and
control of exhaust air temperature to prevent freezing
within the heat exchanger and supply air temperature
for seasonal changes.
• Indirect Evaporative Cooling
Summer energy recovery can be enhanced by the
installation of a direct spray indirect evaporative cooling system on the return air side of the heat pipe heat
exchanger.
5
CONSTRUCTION FEATURES
• Integral Fin Design
Each heat pipe is fabricated using a single piece
of aluminum to eliminate the possibility of fin and
tube separation and to maximize heat transfer.
This design technique also prevents corrosion or
contamination between fin and tube, and creates
a smooth surface for the application of optional
anticorrosive coatings. Integral fin construction is
very durable and withstands high pressure air or
water cleaning.
• Individual Heat Pipes
This means greater reliability in performance,
since failure of one heat pipe has little effect on
the overall performance of the heat exchanger.
• Heat Exchanger Casing
The heat exchanger frame is fabricated using
14-gauge galvannealed steel as shown in the
dimensional data section.
6
• Sealed Center Partition
The partition is fabricated using 16-gauge galvannealed steel. It is provided to prevent cross
contamination between the two airstreams and
can be placed in any position to accommodate
unbalanced flow systems.
• End Covers
End covers are fabricated using 16-gauge galvannealed steel to protect the individual heat pipes.
• Refrigerant
R-22 is utilized as the standard working fluid in
HVAC applications, however, other fluids may be
utilized for specialized applications (contact the
factory).
CONSTRUCTION FEATURES
• Counterflow Design
The counterflow configuration allows Des Champs
heat 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 between
60 and 70%.
• Performance Flexibility
A large selection of row depths and face areas
are available for required energy recovery
performance.
• Quality Assurance
Each heat exchanger manufactured by
Des Champs is subjected to a rigorous quality
assurance process to ensure structural integrity
and conformance with design requirements.
• Lower Installation Cost
By utilizing the simplest airflow configuration,
counterflow, there is typically less ductwork
required to install a heat pipe heat exchanger as
compared to a plate type heat exchanger of equal
capacity.
C U T- AWAY V I E W O F H E AT P I P E
7
APPLICATION CONSIDERATIONS
COUNTERFLOW DESIGN
Having a counterflow design means the exhaust and supply airstreams flow in opposite
directions 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, when
used for heating, ventilating, and air conditioning.
V E R T I C A L I N S TA L L AT I O N
Vertical 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.
M U LT I P L E U N I T C O N F I G U R AT I O N S
For larger airflow applications or where space limitations exist, it may be desirable to
install two or more heat pipe heat exchangers in series or in parallel.
SUPPORTING STRUCTURE
The exchangers should be secured rigidly so as not to allow more than 1/8 inch total bow
end-to-end.
DUCT DESIGN
The exchanger is manufactured with a center partition and frame such that standard duct
flanges can be screwed to the frame, using 3/8 inch length sheet metal screws. The duct
design should be in accordance with good practice in establishing a uniform airflow across
entire coil surface.
8
F I LT R AT I O N R E Q U I R E M E N T S
Performance specifications are based upon clean air and a clean heat transfer surface. It is
required that adequate filtration be utilized in both exchanger airstreams to insure optimum
performance and minimum maintenance.
ACCESS DOORS
Access doors should be provided to allow periodic inspection of the exchanger and to facilitate cleaning when necessary.
D R A I N PA N S
Drain pans are recommended under the entire exchanger both as a condensate collection
system and for cleaning purposes.
T E M P E R AT U R E L I M I TAT I O N S
The heat pipe heat exchanger is a commercial product, designed to be operated at temperatures of 125°F and below. If the hot airstream is expected to exceed 125º F, consult the factory for selection of the proper working fluid.
CODE REQUIREMENTS
Installation of the exchanger should conform to all codes, laws, and regulations applying at
the job site.
INSTALLATION CONSIDERATIONS
C O N N E C T I O N TO OT H E R A I R
HANDLING UNIT SECTIONS
The heat pipe heat exchanger
casing is best connected to the
duct work by means of flanges.
I N S TA L L AT I O N I N A
PA C K A G E D S Y S T E M
The heat pipe heat exchanger is
installed directly on the floor.
Sheet metal safe-offs direct the
airflow through the heat
exchanger.
9
PSYCHROMETRIC DATA
The heat pipe heat exchanger is a sensible heat recovery device. This means latent
heat is not exchanged between the supply and exhaust airstreams, and therefore no
moisture is transferred. However, if the exhaust airstream is cooled below its dew
point, condensation occurs and some latent energy is transferred. Condensation can
thus increase the heat transfer rate and enhance sensible effectiveness, since each
pound of condensed moisture transfers about 1050 Btu to the supply airstream.
The price for this “enhanced” effectiveness comes in the form of increasing pressure
drops 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 in
the winter.
Figure 1 shows a typical sensible heat recovery process.
S E N S I B L E H E AT T R A N S F E R
H E AT P I P E
FIGURE 1
B
10
30
%
50
%
70
%
90
%
In summer, the warmer airstream
(outside air) is cooled from point A
to B, while the colder airstream
(exhaust air) is being heated from
C to D. In winter, the process is
reversed. The colder outside air is
heated from E to F and the warmer
indoor air is cooled from G to H.
A
OUTDOOR AIR SUMMER
C
D
EXHAUST AIR SUMMER
H
G
EXHAUST AIR WINTER
E
OUTDOOR AIR WINTER
35
45
55
ELAT
10% R
F
65
75
85
MID
IVE HU
95
ITY
105
115
DRY BULB TEMPERATURE (DEGREES F)
The figure above shows various operating conditions based upon 70% efficiency.
SELECTION PROCEDURE
DEFINITIONS
FA
DFV
QS
QE
TF
FH
FL
EL
E
TOA
TSA
TRA
=
=
=
=
=
=
=
=
=
=
=
=
SCFMOA =
SCFMMIN =
Total Face Area (in2)
Design Face Velocity per side
Supply Airflow (CFM, ft3/min)
Exhaust Airflow (CFM, ft3/min)
Tubes in Face of Heat Pipe
Finned Height (inches)
Finned Length (inches)
Finned Length–Exhaust Side (inches)
Effectiveness (%)
outside air inlet temperature (°F)
supply air outlet temperature (°F)
return air inlet temperature (°F)
outside air standard CFM
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 of
the finned length. For unbalanced flows, this location can be changed to balance the
pressure loss. This will ensure that the individual airflow velocity is close to the
design. 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) is
defined 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.
11
HEAT EXCHANGER PERFORMANCE
FIGURE 2
70
H E AT E X C H A N G E R
SELECTION EXAMPLE
60
EFFECTIVENESS, %
Select a heat pipe heat exchanger for
4,000 SCFM outside air at 95°F and
4,000 SCFM exhaust air at 75°F with
a minimum effectiveness of 58%.
Selection:
Using Figure 2, DFV = 500 fpm.
FA = 144 x (4,000 + 4,000) / 500 = 2,304 in2
50
30
8
7
6
5
4
20
3 ROW
40
ROW
ROW
ROW
ROW
ROW
2 ROW
For TF = 16, FH = 2.125 x 16 = 34 in.
10
FL = 2,304 / 34 = 67.8 in. [Round to 68]
800
750
700
650
600
550
500
450
400
330
Using Figures 2 and 3, at 500 fpm,
7 rows gives 55% effectiveness and
0.86 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.
350
0
For balanced flow, EL = 34 in. (on center)
FACE VELOCITY (FEET PER MINUTE)
FIGURE 3
A I R P R E S S U R E D R O P, I N . W. C .
2.00
To determine the leaving supply
temperature:
TSA = TOA - E x (SCFMMIN/SCFMOA) x (TOA - TRA)
TSA = 95 - 0.55 x ( 4000 ) x (95 - 75)
4000
TSA = 84°F
12
1.80
8 ROW
1.60
7 ROW
1.40
6 ROW
1.20
5 ROW
1.00
4 ROW
0.80
3 ROW
0.60
2 ROW
0.40
0.20
800
750
700
650
600
550
500
450
400
350
330
0.00
FACE VELOCITY (FEET PER MINUTE)
TA B L E 1
HEAT PIPE AIRFLOWS (CFM)
FIN
# OF
HEIGHT
TUBES
(INCHES) IN FACE
14 7/8
7
21 1/4
10
27 5/8
13
FIN TUBE LENGTH IN INCHES
24
36
620
930
885
48
60
72
84
96
108
120
132
144
156
168
180
192
204
216
228 240
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
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
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
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
8,411 9,253 10,094 10,935 11,776 12,617 13,458 14,299 15,141 15,982 16,823
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.
DIMENSIONAL DATA
2" FLANGE
H
H + 2X*
AIR-TIGHT
CENTER
PARTITION
4"
L
D
X
L + 6
HEAT PIPE DEPTHS
TA B L E 2
ROWS
DEPTH (D)
2
5 7/8
4
3
7 3/4
5 7/8
4
9 5/8
7 3/4
Height (H)
5
11
1/2
5/8
Length (L)
6
13 3/8
11 1/2
7
15 1/4
13 3/8
8
1/8
15 1/4
17
*Value of x:
If L < 14', X=2"
If L ≥ 14', X=3"
FIN DEPTH
9
TA B L E 3
TYPICAL HEAT EXCHANGER DIMENSIONS
14
7/8
21
24
1/4
27
36
5/8
48
34
60
40
3/8
72
46
3/4
53 1/8
59 1/2
96
108-240
84
TA B L E 4
TOTAL BASE WEIGHT FOR 5 ROWS (POUNDS)
FIN
# OF
HEIGHT TUBES
(INCHES) IN FACE
FIN TUBE LENGTH IN INCHES
24
36
48
60
72
84
96
108
120
132
144
156
168
180
192
204
216
228
240
757
805
852
900
947
995
1,042
7/8
7
188
235
283
330
378
425
473
520
568
615
662
710
21 1/4
10
260
322
384
447
509
572
634
697
759
822
884
947
27 5/8
13
331
409
486
563
641
718
796
873
951
34
16
403
495
588
680
772
865
957
40 3/8
19
474
582
689
797
46 3/4
22
546
668
791
913
53 1/8
25
617
755
892
1,030 1,167 1,305 1,442 1,580
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
14
59
904
1,009 1,071 1,134 1,196 1,259 1,321 1,384
1,028 1,106 1,183 1,261 1,338 1,415 1,493 1,570 1,648 1,725
1,050 1,142 1,235 1,327 1,420 1,512 1,605 1,697 1,790 1,882 1,974 2,067
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
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
1,717 1,855 1,992 2,129 2,267 2,404 2,542 2,679 2,817 2,954 3,092
Heat Exchanger Weight (lbs) = Base Weight from Table 5 x Correction Factor
WEIGHT CALCULATION
FINS PER
INCH
2
3
11
0.49
0.66
TA B L E 5
WEIGHT CORRECTION FACTORS
ROWS DEEP
4
5
6
0.83
1.00
1.19
7
8
1.38
1.56
Note: For larger fin height or fin length requirements, multiple exchangers may be combined.
Dimensions and weights are for reference only.
For design purposes, use certified data.
For heat exchanger performance selection contact
the factory or your local sales representative.
13
MECHANICAL SPECIFICATIONS
The packaged humidity control system shall be a Model FHP ______________ as
manufactured by Des Champs Laboratories, Inc. The heat pipe shall transfer heat
between outgoing and incoming airstreams in a counterflow arrangement, and shall
be 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 or
other movement for heat transfer, and shall be capable of operating at temperatures
ranging from -60°F minimum to 125°F maximum.
The heat pipe shall be installed: with 1/4 inch per foot tilt angle exhaust end down
when used for heating and ventilating application only, or within 1/8 inch level
end-to-end when used for heating, ventilating, and air conditioning applications.
Performance data derived from laboratory testing on heat exchanger conditions is in
accordance with ASHRAE Standard 84-1991 “method of testing air-to-air heat
exchangers.” Performance shall be rated in accordance with ARI testing procedures.
14
Manufacturers of alternate equipment must be approved to bid via addendum, in
writing by the specifying engineer, at least two weeks prior to bid time in order for
their bid to be accepted by the contractor. If the equipment is not pre-approved then
under no circumstances shall the contractor invest time or money in receiving submittals or considering the equipment. Costs associated with dimensional, performance, or other deviations from the specified equipment, including engineering
costs to evaluate such deviations, shall be paid by the contractor. The manufacturer
must have a quality management system in place, equal to the quality assurance
standard ISO-9001, for the design, manufacture, and service of heat exchangers and
packaged ventilation/air conditioning equipment. The manufacturer must also have
a net worth greater than five times the value of the equipment being bid and must
have been a manufacturer of air-to-air heat exchangers for at least five years prior
to bid time. The air-to-air heat exchangers must be manufactured in the United
States of America.
D E S I G N A N D C O N S T R U C T I O N F E AT U R E S
1. Heat Pipe Heat Exchanger
Heat pipes shall have 1-inch I.D. seamless, integrally finned 3003 aluminum
tubes with 0.063 inch wall thickness.
Heat pipes shall be a maximum of 2 1/8 inches on center in the face and shall
be 1 7/8 inches on center row-to-row.
Heat pipe fin surface shall be integral to the tube, and shall have a minimum of
0.015 mean fin thickness, tapered root to fin tip. Fin surface from root to fin tip
shall have a minimum of 0.437 inch mean fin height. Fin density shall be 11
fins per inch. Two-component heat pipes such as expanded tube-to-fin shall not
be acceptable in order to prevent efficiency degradation due to eventual weakening of the fin-to tube bond.
Heat pipes shall have a circumferential capillary wick structure integral to the
inside of each individual tube. The capillary wick structure shall be the result of
a knurling process and shall not degrade the integrity of the heat pipe wall.
MECHANICAL SPECIFICATIONS
Heat pipes shall be individually processed, charged, hermetically sealed, and
factory tested.
Heat pipe heat exchanger shall be installed as shown on the manufacturer’s
submittal drawings.
2. Casing
The heat exchanger frame shall be fabricated from minimum 14-gauge galvannealed steel. The frame shall be supplied with a minimum of 2-inch wide
flanges on all four sides, both front and back. Intermediate heat pipe supports
shall be furnished as required.
The heat exchanger shall be provided with a partition to isolate the outgoing
and incoming airstreams; there shall be no cross contamination. The partition
shall be fabricated from a minimum 16-gauge, galvannealed steel and shall
extend beyond the finned surface with a 4-inch mid-seal (2 inches to supply
side and 2 inches to exhaust side).
End covers shall be provided to protect the heat pipe ends. End covers shall be
fabricated from 16-gauge galvannealed steel.
3. Refrigerant
Heat pipe heat exchanger refrigerant shall be selected on the basis of heat pipe
operating temperature and compatibility with heat pipe tube material.
Heat pipe heat exchanger refrigerant used shall be classed as group 1 in the
American National Standard Safety Code for Mechanical Refrigeration.
4. Temperature Controls (Optional)
The following three options are available for temperature control:
A. Face & Bypass Dampers
Face 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 exchanger
module. Dampers shall be constructed of minimum 16-gauge galvanized steel
and operated by a damper motor (specify modulating or two-position) controlled by a thermostat (specify factory or customer provided).
B. Tilt Control
Tilt 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.
15
MECHANICAL SPECIFICATIONS
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 the
center of the heat pipe unit. The arrangement shall be such that the heat pipe
can pivot freely about the axis of the bearings.
The tilt package shall be powered by a heavy-duty drive motor and connecting
linkage.
Temperature sensors shall be placed in the supply entering and leaving
airstreams, 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-contamination
between airstreams, while permitting the heat pipe assembly to tilt. Customer
duct connections shall be rigid.
5. Protective Coating (When Required)
Air dried carboline coating to protect against corrosion. Coating to be factory
applied to supply and exhaust sides.
16
DES CHAMPS LABORATORIES INCORPORATED
P.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)