Duda Solar SC5815 User manual

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Duda Solar Water Heating Systems
Operation and Maintenance Manual
Duda Energy LLC
1112 Brooks St SE Decatur, AL 35601
Phone Contact: 256-340-4866
www.DudaEnergy.com
http://waterheatertimer.org/Convert-AC-water-heater-to-DC-water-heater.html

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Table of Contents
General Information ................................................................................................................................... 5
Local Standards....................................................................................................................................... 5
Qualified Installer.................................................................................................................................... 5
Warnings and Cautions ........................................................................................................................... 5
Pressure Release & Relief Valve.............................................................................................................. 6
Water Quality.......................................................................................................................................... 6
Metallic Corrosion................................................................................................................................... 7
Connection of Piping............................................................................................................................... 8
Freeze Protection of the Closed Loop System......................................................................................... 8
Freeze Protection of the Copper Heat Pipes ........................................................................................... 8
SRCC Certification & collector specifications .......................................................................................... 9
Manifold Connections........................................................................................................................... 14
Wind Stress ........................................................................................................................................... 14
Snow Loading........................................................................................................................................ 15
Storage Tanks........................................................................................................................................ 15
Hail Resistance...................................................................................................................................... 15
Pipe Sealant .......................................................................................................................................... 15
Scope of Manual ................................................................................................................................... 15
Definitions............................................................................................................................................. 15
Equipment Supplied by Duda Energy For a Complete System .............................................................. 16
Additional Parts/Equipment Recommended From Duda Energy .......................................................... 16
Tools & Materials Needed .................................................................................................................... 17
System Operation ..................................................................................................................................... 17
Explanation of components ...................................................................................................................... 19
Solar collector ....................................................................................................................................... 19
Accessory Frame Construction.............................................................................................................. 20
Working Station .................................................................................................................................... 23
Electrical Installation......................................................................................................................... 24
Pressure relief Valve ......................................................................................................................... 24
Mounting the Electronic Controller .................................................................................................. 25
Flow Meter........................................................................................................................................ 25

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Tubing ................................................................................................................................................... 26
Electronic Controller ............................................................................................................................. 26
Controller display.............................................................................................................................. 26
Controller.......................................................................................................................................... 26
Backup Heating function................................................................................................................... 28
System Set-up ................................................................................................................................... 28
Solar water Tank ................................................................................................................................... 29
Mounting Feet .................................................................................................................................. 29
Temperature/Pressure Relief............................................................................................................ 30
Cold water Inlet Port......................................................................................................................... 30
Lower Circulation Loop Ports ............................................................................................................ 31
Bottom temperature Sensor Port ..................................................................................................... 32
Electric Water Heating Backup.......................................................................................................... 32
Upper Circulation Loop Ports (Optional)........................................................................................... 33
Magnesium Rod / Anode rod ............................................................................................................ 33
Hot Water Outlet .............................................................................................................................. 34
Drain port (Bottom side of the tank)................................................................................................. 34
Thermostatic Mixing valve .................................................................................................................... 35
Duda’s Flex Tubing / Corrugated Stainless Steel Tubing ....................................................................... 37
Step 1: Slide the fitting over the tubing ............................................................................................ 37
Step 2: Flatten the corrugations using the special fitting tool........................................................... 38
Step 3: Apply the c-ring to the tubing ............................................................................................... 38
Step 4: Pull the fitting forward.......................................................................................................... 39
Step 5: Apply the washer .................................................................................................................. 39
Step 6: Attach to your piping ............................................................................................................ 40
Installation ................................................................................................................................................ 41
Transport Unpacking and Inspection .................................................................................................... 41
Location Requirements ......................................................................................................................... 41
Electrical Requirements ........................................................................................................................ 42
System Design....................................................................................................................................... 43
Direction and Angle of Installation........................................................................................................ 44
Mounting the Frame ................................................................................................................................. 45

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Slope Roof Installation ...................................................................................................................... 45
Bracing .............................................................................................................................................. 46
Flat Roof or Ground Installation........................................................................................................ 46
Wall Mounting .................................................................................................................................. 47
Installing the Components to the Frame .............................................................................................. 47
Mounting the Manifold..................................................................................................................... 47
Piping & Automatic Air Vent ............................................................................................................. 48
Insulation .......................................................................................................................................... 48
Charging the System ......................................................................................................................... 49
Installing the Vacuum Tubes ............................................................................................................. 50
Reflectors.............................................................................................................................................. 56
Maintenance............................................................................................................................................. 57
Cleaning ................................................................................................................................................ 57
Leaves ................................................................................................................................................... 57
Broken Evacuated Tubes....................................................................................................................... 57
Flushing the System .............................................................................................................................. 57
Instructions for long periods of inactivity ............................................................................................. 57
Anode Rod Maintenance ...................................................................................................................... 58
Draining the Solar Water Tank .............................................................................................................. 58
Emergency Shutdown Procedures ............................................................................................................ 58
To Turn off the solar system ................................................................................................................. 58
To turn off the water ............................................................................................................................ 58
Troubleshooting........................................................................................................................................ 58
No Hot Water........................................................................................................................................ 58
Warranty................................................................................................................................................... 59
Disclaimer ................................................................................................................................................. 59

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General Information
Please read this manual in its entirety prior to installing your Duda Solar water heater.
This manual covers the general installation of the solar water heater but may not be a complete
resource for the full installation or safety requirements for performing an installation. These
systems should be installed in accordance with all local building codes.
Local Standards
This installation must be done in accordance with all local, state and federal regulations.
Check with your local building code and code enforcement prior to installing a solar water
heater. Local codes/regulations take precedence over the guidelines in this manual.
Qualified Installer
Duda Energy LLC does not take responsibility for improper installation of its Solar Water
Heaters. Only people with plumbing, roofing and electrical knowledge should install a solar
water heater. Duda Energy LLC recommends that a qualified/certified plumber or solar installer
who holds a license required for such industry should install this product.
This water heater should be installed in accordance with the local code authority which
has such jurisdictions over the installation, the utility company and this installation manual. If
there are no local code requirements, follow the regulations found in the latest edition of The
National Electric Code, NFPA 70. This may be obtained from the following organizations:
National Fire Protection Agency
1 Batterymarch Park
Quincy, MA 02269
American National Standards
Institute
1430 Broadway
New York, NY 1001
Use your phonebook listings for the local authorities having jurisdiction over your installation.
Warnings and Cautions
When the term “Warning” is used it means that a person could be injured or killed if
the procedure is not adhered to. The term “Caution” means that a person has a
chance of being injured or worse if the procedure is not adhered to. “Notes” signify
something regarding general tips for operation of the unit.

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Pressure Release & Relief Valve
Caution: The closed system solar loop must operate at less than 87 psi and
have an expansion tank installed to accommodate expansion from the
working fluid.
Caution: The closed loop system design must eject fluid at no more than 113
psi. It is recommended that the pressure relief valve be operated every 6
months to ensure reliability and operation. Please raise and lower the
release lever gently and carefully as the working fluid of the system can be
extremely hot.
Caution: The solar water tank must be equipped with a
temperature/pressure relief valve. It must relieve pressure at no higher than
99°C / 100 psi. The T/P valve should be operated every 6 months to ensure
reliability and operation. Please raise and lower the release lever gently and
carefully as the working fluid of the system can be extremely hot.
Warning: Failure to operate the pressure temperature relief valves on a
regular basis could lead to failure of the component or possible solar storage
tank explosion and damage to the solar system.
Water Quality
Water needs to be added to propylene glycol for the working fluid of the
system. It is recommended that distilled water be used to help prevent
corrosion to the plumbing and system parts and to also ensure efficient heat
transfer. The water quality must meet the following requirements:
Chloride
< 250 ppm
Hardness
< 200 ppm
Magnesium
< 10 ppm
Dissolved Solids
< 600 ppm
Chlorine
< 5 ppm
Caution: Only food grade propylene glycol mixed with water may be used to make an antifreeze
solution in the solar loop. The Duda Energy Inhibited Propylene Glycol has special corrosion
inhibitors which will coat the inside of the piping in the solar loop. This helps prevent corrosion
within the closed loop system, especially in the case of the propylene glycol becoming acidic over
time.
Warning: Do not use ethylene glycol (automotive antifreeze) for your solar loop. This chemical is
toxic and may cause death should failure occur within the system causing it to mix in with the
water in the tank. Only Food Grade Propylene glycol may be used in a solar water heater system.

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When mixing the propylene glycol with water, do not use a solution of more than 60% propylene
glycol to 40% water by volume unless otherwise instructed by the manufacturer. The propylene
glycol solution should only be concentrated enough to avoid the coldest possible temperatures in
the region. Higher propylene glycol concentrations will reduce the heat transfer and pumping
efficiency.
Propylene glycol solutions will gradually become more acidic over time and should be changed out
every 3 to 5 years to prevent excessive corrosion to the pipes. If the propylene glycol solution
exceeds 250ºF on a regular basis, it should be changed more frequently as propylene glycol will become
rapidly acidic when kept above this temperature.
You should obtain a water quality analysis of your water supply prior to installing the solar water
tank. Most of the time, these tests can be obtained from your water authority as they are required
to perform this test and keep the results on record. If the water comes from a well, a water quality
test should still be performed.
If your location has “hard” water, the inside of the solar tank will become coated with lime scale,
thus reducing the efficiency and life expectancy of the tank. It is recommended that a sufficient
softening device be utilized for effective long term operation of the tank.
The anode rod in the solar water tank is used to protect the inner walls of the tank from corrosion
by use of the phenomenon known as galvanic corrosion. The anode rod, which is less noble than
stainless steel, will corrode first before the stainless steel walls can corrode. Regular replacement
of the rod will greatly extend the life of the tank. This rod should be checked every few years or
replaced according to the below anode replacement schedule.
Dissolved Solids in Water (ppm)
Replacement Interval of Anode
0 –600
5 Years
600 –1000
3 Years
1000
2 Year or Less
The Duda Solar water heating tank is initially equipped with a magnesium anode rod. Magnesium
anode rods dissolve into the water as they corrode and provide healthy minerals to the water
supply. Alternatives to the magnesium rods are aluminum or zinc-aluminum combinations. The
aluminum-type rods are nobler than magnesium rods and will last a little bit longer than
magnesium rods. Aluminum anode rods are preferred if your water supply contains very hard
water. Zinc-aluminum (10% zinc, 90% Aluminum) rods can be used if the water has a sulfur dioxide
odor. The zinc can help remove this order.
Metallic Corrosion
Duda Energy does not warrant the solar collector or solar water heater tank against corrosion related damage.
Always use high grade copper or Duda’s Flex tubing (corrugated stainless steel tubing) in the solar loop. The heat
generated by the solar collectors can leach impurities into the working fluid of the system.

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Warning: Do not use iron or PEX tubing in the closed loop section of the solar system. Iron piping fails
easily due to corrosion effects of the working fluid and the ambient air. PEX tubing or any kind of plastic
piping will melt from the extreme temperatures of the solar water collector.
Connection of Piping
Copper must be soldered using high temperature silver solder. The use of compression fittings or such equivalent
fittings are acceptable for connecting copper pipes. Flexible stainless steel tubing must be attached using the threads
and a high temperature gasket.
Freeze Protection of the Closed Loop System
The manifold and piping could become damaged from cold temperatures due to expansion of the working fluid in
the case of freezing. A Food Grade Propylene Glycol solution should be used for maximum freeze protection in the
closed solar loop. Refer to the temperature chart below for the appropriate mixture ratio based on your location. It is
best to recognize that solar collectors on a roof will experience the coldest parts of the night and should have a
solution able to withstand the coldest possible climate in your area. While the highest concentration may seem the
best for the highest freeze protection, the lowest concentration permissible by weather should be used as heat
transfer and pumping is more efficient with higher concentrations of water.
Note: No more than 60% propylene glycol should be used as higher concentrations have low heat conduction and
high viscosity which may hinder performance of the circulation pump.
Solution (% by *mass)
10
20
30
40
50
60
Freeze Temp (°F)
26
18
7
-8
-29
-55
Boiling Temp (°F)
212
213
216
219
222
225
*The density of propylene glycol is very similar to that of water so a volume/volume ratio may be used in
substitute to mass/mass.
Note: Duda Energy’s Special Inhibited Food Grade Propylene Glycol is highly recommended. It will coat the inner parts
of the metal piping with corrosion inhibitors. This will help prevent corrosion to the pipes as the glycol solution
becomes acidic over time.
Freeze Protection of the Copper Heat Pipes
The evacuated tubes and heat pipes are not normally susceptible to damage in mild cold climates. The
standard Duda Solar copper heat pipes (0.6mm thickness) are rated for -10°C (14°F) operating temperatures. It is
generally acceptable for the heat pipes to endure 5–10°C (9-18°F) lower than their rated minimum operating
temperatures for intermediate periods. However, if cold temperatures are expected to normally exceed this
minimum temperature requirement, Duda Solar freeze resistant heat pipes should be considered to avoid cracking of
the heat pipes. Use the below chart as a guide for Duda Solar Freeze Resistant Heat Pipes.
Model
Low Temperature
High Temperature
Heat Pipe
Condenser

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Rating
Rating
Thickness
Cover
Standard
-10°C (14°F)
230°C (446°F)
0.6mm
No
Freeze Resistant
-25°C (-13°F)
250°C (482°F)
0.7mm
No
Super Freeze Resistant
-50°C (-58°F)
250°C (482°F)
0.8mm
Yes
SRCC Certification & collector specifications
The Duda Solar Water Heater Collectors are OG-100 SRCC Certified. They are one of the most efficient solar water
heaters in the market. They have a very high performance in both warm and cold weather due to its excellent design
in manifold technology and quality evacuated tubes.
OG-100 certified collectors are eligible for the 30% Federal Tax Rebate for alternative energy. All components
involved in the installation and labor may be considered for the tax rebate.
Following are copies of the SRCC report for each collector offered by Duda Energy LLC. To view the full pages
of the SRCC report, please visit www.solar-rating.org and go to Ratings and search by entering the corresponding
SRCC certification number into the appropriate field for search Duda Energy LLC by company name.

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Manifold Connections
There are two connections on the manifold, an inlet and an outlet. The fluid can flow in either direction. The
flow of the fluid should be oriented so that the outlet of the manifold is also where the solar collector temperature
sensor is installed. This is especially important for systems which have many collectors linked together since there can
be great temperature differences between the inlet of the collectors and the outlet of the collectors.
Note: The manifold must be elevated at a minimum of 5° above the vacuum tubes in order for rapid transfer of the
heat from the tubes to the manifold to through the use of evaporation of the special fluid inside of the heat pipes.
The header pipes on the manifold are ¾” copper pipes. Pipe connections may be made by soldering with a
high quality silver solder or with the use of compression fittings.
Warning: Only high quality silver solder should be used as the high temperature of the operating unit can cause
failure in low temperature products.
Wind Stress
When installing the collector, consider orienting the collector for wind resistance and take notice to the
stresses on the attachment points. The installation must be made according to building codes/regulations regarding
the installation of the unit.
Caution: When installing in windy conditions take precautions as the unit can be caught by the wind and damage to
the unit or persons can occur.
It is the responsibility of the installer to ensure that the frame mounting area is of suitable strength. When
applicable, a building inspector or equivalent should authorize the location of the installation to ensure that it will be
done within all relevant regulations. Proper safety techniques should be practiced when installing the unit. If there
are any doubts, contact your building inspector.
Caution: Placement of the solar unit should consider the possibility of broken tubes and glass shards falling on people
or animals from incidental contact.

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Snow Loading
In areas where significant amounts of snow accumulation can occur, it is recommended that the solar
collectors be elevated. Please refer to local and other regulations regarding snow loading precautions.
Storage Tanks
Tanks must be installed in accordance with local building codes. Use additional braces or straps when installing
the tank in earthquake zones.
Warning: When solar storage tanks are operated for an extended period of time without any hot water use, there can
be a buildup of hydrogen gas in the top of the tank. If the tank’s water supply is not operated frequently, run the hot
water for several minutes to drain out all of the hydrogen gas. Do not operate a dishwasher or other hot water
appliance until this gas has been discharged to avoid a potential ignition of the gas. When draining this gas from the
tank, it will sound like air in the pipelines.
Hail Resistance
The solar water heater vacuum tube is extremely tough against hard impacts. The tubes are tested to withstand
impact from hail up to 25mm in diameter (about one inch diameter). Even larger hail bombardment can be tolerated
if the collector is oriented at an angle greater than 45°. If you live in an area where storms often generate hail greater
than 25mm in diameter, it is highly recommended to orient the solar collector greater than 45°.
Pipe Sealant
High quality Teflon tape should be used for all NPT threaded fitting connections. We offer a yellow “gas line”
Teflon tape which meets Mil SPEC T27730A, a military specification. Use of this Teflon tape will ensure a leak-free
connection for years to come.
Scope of Manual
This manual is written for the reference of a qualified plumber or solar installer. This manual is not a full
encompassing manual. Other resources should be gathered prior to installing the system. If conflicting information is
found, the owner’s manual takes president. Duda Energy LLC is not responsible for damages to property or persons
due to solar water heater installations.
Definitions
Automatic Air Vent –A vent installed at the highest point of the system to ensure the closed-loop
system remains free of air.
Closed Loop Pressurized System - A solar system which uses a separate fluid to transfer heat to a
solar tank. The system is closed from other fluids and pressurized.

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Tank Coil –Coils or heat exchangers are immersed inside of the solar tank which permits transfer of
heat from the closed loop pressurized system to the water. These coils are ½” or ¾” OD copper
tubing coils which keep the solar loop working fluid from mixing with the domestic water.
Heat Dissipater –Similar to a car radiator. A devise used to radiate off excess heat from the solar
system.
Heat Pipe –A high grade copper pipe which transfers heat to the manifold. The pipe contains a
fluid which rapidly transfers heat to the manifold through evaporation in the bottom of the pipe
and condensation in the top of the pipe. The top of this heat pipe is called the condenser. The
condenser is inserted directly into the manifold.
Solar Panel or Solar Collector –A complete unit which mounts to the roof or ground consisting of a
manifold and vacuum tubes.
Solar Tank –The water storage tank which the solar collector delivers heat to through the use of
the closed loop.
Solenoid Valve –An electrically controlled valve which is used to control flow through the heat
dissipater when the solar loop reaches maximum working temperature.
Temperature Pressure Relief Valve (T/P Valve) –This is a safety valve which ejects water if the
temperature or pressure inside the solar tank exceeds maximum specifications.
Thermostatic Mixing Valve –A mechanical valve which automatically mixes cold and hot water to
an adjustable temperature.
Working Station –The assembled unit containing the circulation pump, pressure gauge, tempering
valve, pressure relief valve and flow meter.
Equipment Supplied by Duda Energy for a Complete System
Box with Manifold, mounting frame, optional back legs for stand, tube holders/end caps, mounting
feet and thermal conducting compound
Boxes of vacuum tubes with heat pipes and aluminum fines inserted
Box of spare vacuum tubes for breakage insurance during freight
Working Station (pump assembly and electronic controller)
Solar Water Tank
Inhibited food grade propylene glycol, automatic air vent, thermostatic mixing valve, submersible
water pump for initial charging of the system
Note: Larger Systems may have more than one manifold with corresponding parts and also more vacuum tubes with
and without heat pipes.
Additional Parts/Equipment Recommended From Duda Energy
Flexible corrugated stainless steel tubing and corresponding fittings with fittings installation tool or
copper pipe (stainless is preferred over copper for better corrosion resistance, less heat loss and
easier installation) Enough pipe will be needed for connecting the solar collector to the working
station and water tank.

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Nitrile/NBR/Buna/EPDM or other high temperature resistant pipe insulation
Aluminum Pipe Wrap for protection of insulation exposed to weather
Copper wire for extending connections to the solar collector temperature sensor
Compression fittings for connecting the system components to the piping
PVC tubing for connecting the
High Quality Teflon Tape for NPT pipe connections
5 Gallon Pail for holding the working fluid during initial charging of the system
Note: Duda Energy offers most of the needed components in a turn-key option. Call for details.
Tools & Materials Needed
2 Adjustable Crescent Wrenches
1 small pipe wrench
High temperature lubricant
Ladder(s) for access to roof and attic as needed
Measuring tape, square, marking pencil or chalk (for marking rafters and holes on roof)
½” wood bit or a circular hole bit for roof penetration (for feed and return lines through the roof)
8 Bolts/washers/Screws/Nuts to mount unit to the roof (8 per collector)
2 rubber roof penetration boots and screws to mount
Pipe clamps to hold pipes in place
Caulking gun with a quality silicone roofing caulk (to fill lag holes and seal flashing to prevent leaks)
Pipe cutters
Drain pan for solar water tank
Strapping for any part of the system (for earthquake zones or high wind areas)
Small and Large Philips screwdrivers
Small flat head screwdriver
Hammer
Plastic zip ties to hold wires in place
Necessary copper connections for ¾” pipe on manifold to attach to stainless tubing or copper pipe
Fittings to connect your water system to the tank and any necessary plugs if any ports will not be used
Electric ring terminal for grounding the water heater element to thermostat housing screw
Pipes for connecting water supply to the solar water tank
System Operation
The operation of the closed loop solar water heater system incorporates simple and reliable products which
collect heat from the sun through the solar collector and transfer the heat using the working fluid (propylene glycol)
to the solar water tank by use of the heat exchanger coil in the bottom of the tank.

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Solar water heater vacuum tubes are a state of the art technology which were originally used only in
commercial applications but have now become affordable as the ultimate use in energy conservation for both
residential and commercial applications. The following diagram displays an overview of the system and how it
operates:
Duda Energy Closed Loop Solar Water Heater System

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Explanation of components
Solar collector
The solar collector consists of the manifold, vacuum tubes and frame.
Warning: Ensure the roof is structurally secure before installing the solar collector. If in doubt, consult an engineer or
the local building inspector. The roof must be able to support the weight of the collector with tubes installed and able
to withstand any additional weather loads such as snow and wind. Additional bracing may be required.
Caution: Do not install the vacuum tubes into the manifold until the unit is ready to operate with water in the solar
tank and the closed loop is charged with the propylene glycol mix. The solar loop must be tested for leaks and proper
pump operation must be confirmed. Keep the vacuum tubes out of the sunlight until they are ready to be installed
into the manifold. The heat pipes will heat rapidly when the tubes are exposed to the sun and may cause serious
burns to the installer. Perform the installation of the tubes in the late afternoon or early morning or wear
temperature retardant gloves when inserting the heat pipes with tubes into the manifold.
See below for a photo of the heat pipe and aluminum fins which keep the heat pipe centered inside of the
vacuum tube. The aluminum fins help heat rapidly transfer from the hot air to the heat pipe. The silicon gasket is used
to seal the open end of the vacuum tube to the manifold to help contain the hot air within the tube and to prevent
dust from entering the tube.
Copper Heat Pipe with Silicon Gasket Stopper and One-Piece Aluminum Fin

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Accessory Frame Construction
Below are photos of the solar collector frame to reference when building the frame. For the flat roof stands, the
back legs on the frame are optional and can be removed if you wish to mount the collector flush to the roof. Our
slope roof frames may also be used for flush to the roof installations and also have the special ability of mounting
underneath the tiles on a tile roof for a leak-proof design.
Note: It is best to make the bolts hand-tight on initial building of the frame. Secure the bolts tightly using a wrench
when everything is pieced together and verified to fit correctly.
Note: The Flat Roof / Ground Stand has holes drilled specifically for the left and holes drilled specifically for the right
side of the frame. Be sure to check where the holes are drilled for the cross-members to ensure that each piece is
connected to the proper side of the frame, otherwise the cross-members will not have holes to mount to properly
37°/45° Flat Roof/Ground Stand
Rear view of Flat Roof / Ground Stand