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Copyright © 2014 

Ikhwezi Solar (Pty) Ltd, Novatherm CC, Solar Assist (Pty) Ltd

 

 

5.

 

Frost, scaling and hail resistance, stagnation 

5.1

 

Hail resistance 

NovaSun collectors are hail resistant with 4mm toughened glass and have 
passed SABS hail tests. 

5.2

 

Freeze protection 

Solar hot water systems can be classified as (i) direct: freeze resistant, (ii) 
direct: non freeze resistant or (iii) indirect. 

5.3

 

Direct systems – Freeze resistant 

In direct systems the water to be used in the household circulates through 
the collector, transferring solar energy into the solar geyser.  

The Novasun panel contains a fully insulated heat exchanger that acts as a 
freeze resistant mechanism, as declared by the manufacturer. The pipework 
connecting to  the solar geyser must be  insulated with Insulflex insulation 
material.  

When installed with a PEX-lined Solartherm Cylinder it can be used in all SA 
climate locations (i.e in areas where frost occurs and areas, where ambient 
temperature may fall below 5°C). Contact Solar Assist to discuss water 
quality matters. 

5.3.1Direct systems: non-Freeze Resistant 

In direct systems the water to be used in the household circulates through 
the collector, transferring solar energy into the solar geyser.  

Direct systems are used in 

frost-free locations

, where ambient 

temperature never falls below 5°C and where water quality is good (i.e. less 
than 600ppm total dissolved solids/minerals).  

5.3.2Indirect systems 

In indirect systems the potable water used in the household does not 
circulate through the collectors, but remains in the geyser and is heated 
indirectly by a heat exchanger.  

There are two basic types of heat exchanger, namely a jacketed system 
where an inner cylinder is surrounded by a secondary outer layer and an 
internal heat exchanger where the solar geyser contains an internal copper 
pipe structure. 

In both cases the solar loop (i.e. the pipe work to and from the collectors) 
contains a heat transfer medium (i.e. propylene glycol/water solution) which 
is physically separated from the potable water.  

Propylene glycol has a lower freezing point and prevents the liquid in the 
collectors from freezing and damaging the collector through expansion that 
occurs when ice forms. Only food grade glycol should be used. 

Indirect systems are used in locations where frost occurs and the 
ambient temperature drops below 5°C 

and/or where water quality is 

poor (i.e. more than 600ppm total dissolved solids/minerals).  

These collectors are resistant to freezing only when installed with an indirect 
geyser and the solar loop filled with a solution of propylene glycol and 
water. Water alone must not be used as a transfer fluid. The glycol / water 
solution should be mixed in a glycol to water ratio of 1:3 (i.e. 33% glycol). 

5.4

 

Scale resistance 

Indirect systems containing a glycol solution also prevents scale build up 
inside the collector in areas of poor water quality. It is important to note that 
the geyser itself may still be affected by water quality as would be the case 
with any conventional enamel-lined geyser unless a Solartherm PEX-lined 
geyser is used. 

If a direct system is used in areas of poor water quality the pipe work inside 
the collector and solar loop may be subject to a build-up of scale. This may 
be avoided through the use of a water softening system. This is good 

practice regardless of type of system, as the water will affect other 
household appliances in any event. 

In the event collectors experience scale build-up the performance 
of the system will decrease. Should this occur the system can be 
flushed with a mildly acidic solution (e.g. vinegar solution) and in 
the case of the Novasun collector, the Header Pipe should be 
flushed. The pipe work should then be flushed with fresh water 
after removal of scale prior to re-commissioning. 

Ensure you are familiar with the relevant tank manufacturer’s warranty 
terms and conditions in respect of water quality, particularly as it relates to 
anode replacement in case of enamel-lined tanks. 

 

6.

 

System placement and orientation 

A number of basic fundamentals need to be observed when installing any 
solar hot water system.  

6.1

 

Collector orientation 

Optimum system performance is achieved when the collectors face directly 
North (i.e. true North) when installing in the Southern Hemisphere. The 
closer the collector is to directly facing the equator the greater the amount 
of solar radiation the collector will be exposed to and the greater the 
potential for heating. 

 

Angles up to 45° either side of North will not have a major effect on the 
system performance given the state of the art technology used in the 
construction of the NovaSun systems. Therefore, roofs that are orientated 
away from North are also acceptable for installation.  

Outside of the 45° range one could consider utilising more collector surface 
area or using a mounting frame to adjust the orientation back to North.  

6.2

 

Shading 

With a system orientated to face North, the time period when the collector is 
exposed to the most direct solar radiation is between 10h00 and 16h00.  

Solar collectors with an East bias will achieve a greater gain in morning 
hours and those with a West bias will do so in the afternoon. 

Care should be taken to ensure that the collectors are not subjected to 
excessive shading from trees or adjacent buildings, particularly between 
09h00 and 16h00.  

Also bear in mind that tree growth could lead to future shading issues.  

If the installation takes place in summer, it is also important to take into 
account the lower solar angles in winter, which result in longer shadows. 

 

 

Содержание NovaSun 150l

Страница 1: ...ter Systems October 2013 For use by trained qualified personnel only Applicable to the following models Novasun Direct Freeze Resistant 150l 200l 300l We reserve the right to change the installation instructions Reproduction even partial is only allowed with written permission WE Geysers Pty Ltd 7 Nelmapius Street Chamdor Krugersdorp 1754 novasun solarassist co za www novasunsolar co za ...

Страница 2: ...ing process 7 8 1 Suggested mounting method 1 7 8 2 Suggested mounting method 2 8 9 System Installation 8 9 1 General installation technique 8 9 2 Cylinder and System plumbing 8 9 3 Geysers 9 9 4 Electrical connection 9 9 5 Installation Diagrams 9 Pumped System Installation Diagram 9 10 System commissioning 11 10 1 Commissioning direct systems 11 11 Installation checklist 11 12 System Selection an...

Страница 3: ...ty Ltd does not accept liability or responsibility for the final fitness of water for consumption from this water heater as the water quality is not affected by the system and is a function of the municipal and or other water supply This manual has been written with the intention of ensuring that the system is correctly installed and that the owner user is fully conversant with the best methods of...

Страница 4: ... the natural circulation of fluid between the collector and the geyser In order for the thermo siphon process to occur the geyser must be placed in a higher position than the solar collector The system operates according to the laws of thermal dynamics i e a liquid when heated becomes less dense and rises above the denser cooler liquid Heated water rises up through the collector and into the geyse...

Страница 5: ...mixed in a glycol to water ratio of 1 3 i e 33 glycol 5 4 Scale resistance Indirect systems containing a glycol solution also prevents scale build up inside the collector in areas of poor water quality It is important to note that the geyser itself may still be affected by water quality as would be the case with any conventional enamel lined geyser unless a Solartherm PEX lined geyser is used If a...

Страница 6: ... Ensure that the roof covering material is structurally sound to receive the weight of the system In the case of a split system installation a wooden frame should be constructed which raises the tank above the level of the collectors Care should be taken in the design and construction of this frame so as to ensure it meets all relevant standards 7 Mounting methods 7 1 Selection of appropriate moun...

Страница 7: ...f covering is then placed back into original position c The bracket is placed underneath the geyser foot plate with the bolt sliding through the slotted hole and tightened using the wing nut as supplied d Note the correct use of left hand and right hand bracket Attached strapping is then tightened onto the timber structure in the same way as above NovaSun tanks are equipped with extra anchor point...

Страница 8: ...le leaks The collector is positioned into the collector bracket as demonstrated in the image above A slight kick of 25mm from the cold inlet side to the hot outlet side of the collector is recommended i e cold side lower than hot side by 25mm In the case of sheet roofing as depicted in the following image a roof screw can be removed the strap placed over the existing hole and the roof screw reinse...

Страница 9: ...hat the drain cock is at the lowest point of the tank Once the tank is in place fix the hoop in place and replace tiles 9 System Installation 9 1 General installation technique During fitting and prior to filling the system must be protected against the entry of dirt and water After the system has been mounted it must be flushed in order to remove any debris e g metal chips packaging residue sawdu...

Страница 10: ...s which require regular servicing as well as allowing for the required SANS height of vacuum breakers above the tank 9 4 Electrical connection All electrical work must be carried out by properly qualified and registered electricians Novasun recommends the installation of a time switch when undertaking a solar installation This optimises the performance of the system and is specifically required wh...

Страница 11: ...CC Solar Assist Pty Ltd 10 Pumped Controller Geyserwise System Acknowledgment Geyserwise Installation Manual For purpose of Pump controller installation and wiring instruction refer to the Geyserwise Installation manual or go to www geyserwise co za ...

Страница 12: ...o pressurise Check all piping joints and fittings for water leaks Check pressure relief valves to ensure correct operation Turn on the electric backup element Make sure the tank is completely filled before turning on the element Ensure power is available to the backup element Ensure the time clock has been correctly set 11 Installation checklist The following checklist should be observed by the in...

Страница 13: ...ken per day and how many litres are used how many baths are taken and size of baths how much hot water goes towards washing dishes and doing laundry etc Only once this information is analysed can a final recommendation be made on system size 12 3 System type System type can relate to a number of system characteristics as follows Direct vs Indirect refer section 5 above Close coupled vs Split refer...

Страница 14: ...ar system Time clock settings should generally speaking be set for two hours in the morning and two hours in the evening For example if you bath at 06h30 and 18h00 set your time clock for 04h00 to 06h00 and again for 15h00 to 17h00 Ensure backup time periods do not coincide with localised load shifting by municipalities employing ripple relay devices This will ensure that if there was not sufficie...

Страница 15: ...e cylinder transfers some of its heat to the cooler water in the lower section of the cylinder This effect is often perceived as heat loss but is actually the redistribution of stored heat more evenly over the entire contents of the storage tank This may make it necessary to use the electric element to raise the water in the top section of the cylinder back to an acceptable temperature Over night ...

Страница 16: ...switched off i e approximately 72 hours depending on the model 13 6 Freeze protection liquid No freeze protection liquid is used in the Novasun system 13 7 Setting the time clock WE Geysers Pty Ltd recommends that an SABS approved time clock with battery backup be installed on the distribution board There are many such time clocks on the market and the operation of which are all relatively similar...

Страница 17: ...e timer and provide the geyser with a constant supply The Bypass on display flashes Press the Bypass Off button for power to be controlled by the timer and switch on according to the set times Press the function button to return to screen one Note When in Bypass On mode the display will not revert to screen one after 60 seconds Should you be away from home for any extended period and you wish to s...

Страница 18: ...ure valves and tempering valves should be conducted on a solar geyser just as it should be done on any conventional electrical geyser These valves allow for the safe operation of the geyser and should be inspected twice yearly The temperature pressure TP valve is near the top of the water heater and is essential that this valve operates safely It is possible for the valve to release a little water...

Страница 19: ...ll or part of the day Hot water usage has not been excessive Hot water is not leaking from within the plumbing system that feeds hot water to the points of use The time clock is operational and has been programmed correctly The electric meter and or display light on the time clock speeds up when the time clock is active Power has been provided to the main board i e no electrical faults or load she...

Страница 20: ...td 19 17 Warranty Services log warranty services Important Notice Making use of a non accredited Solar Installer to perform warranty work on your Novasun SWH system will void your Warranty Agreement Date Service Provider Contact detail Services Job performed Owner Notes ...

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