TooHotTooHandle
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@Tweak
Please be more specific who you are calling a nab...
Please be more specific who you are calling a nab...
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and they will refuse to pay the rebate to you. In any configuration with an existing geyser, only one may have an electrical element, either the conventional or solar, not both. Eskom do random inspections, so beware, they'll withold the rebate and pull the installers accreditation. I am not a big fan of prefeed systems, they tend to not be as efficient as a stand alone solar system, because the conventional tanks just don't have the thermal insulation that the solar geysers have. Geyser blankets work, but they have their limits.This type of installation would then not necessarily have a electrical connection to the solar cylinder(it could for extra back-up volume though)
In PE you can buy geyser like the one in the flyer next to the road for R7000.![]()
Hi all, Pietb, thanks for a candid thread.
I am currently looking at quotes from 3 installers.
One of them has suggested that he can link the 200l swh to my existing geysers (not sure of the sizes, but lets say 250 and 150).
The guy recons that the thermo siphon will be enough to heat both geysers.
How ever one of the other installers said something about energy loss.
My question is, 'does linking the SWH to existing geysers make sense?'
Ishisheean
Yes it will work and could work very well depending on your hot water usage. The solar geyser will act as a pre-heater for your existing geysers.
Please ask the installer to insulate ALL hot water pipes.
Can the solar geyser handle the high pressure? Not all can as far as I know. But can the vacuum tubes??
@Spiff
It can be done using a "differential thermostat"
This devise measures two (or more) temperature sensors and will enable(trigger) a pump (via a relay/solenoid) when a difference (delta that can be set) is found.
One sensor is located at the pool (preferably on the point where water is taken(the cold feed point) and the other sensor is situated at the exit point (hot return point) of the swimming pool collector.
If you set the "differential controller" to a 6 degree C (delta set point) the pump will only start if the "hot sensor" (at the collector outlet) is higher than 6 degrees from the "cold sensor" measurement.
Many forms and variations of controllers can be gotten that could be digital or solid state.
See this link for: http://solardome.co.za/index.php/Steca/Thermal-Controllers/Steca-STR-1/flypage.tpl.html
Be aware that these controllers are not able to handle the current of your pool pump, and will require a separately triggered solenoid activated switch(most electrical shops carry them)
Hi
I supply and install solar water heaters and everything else solar in the Port Elisabeth area and surrounding country side.
Just some thoughts and pardon the grammar. Ek is net 'n boertjie.
Depending on the size and type of SWH my mark up on the components are between 15 and 20%. Hardly fireworks. Between the mark up and my installation costs I must survive. The people who make the money is the importers of components - not the local supplier/installer.
With a mark up of 30% the business is dead.
The Eskom subsidy scheme is a joke. In most instances it is cheaper to buy a system without the subsidy than with it. I believe the scheme will change in future.
Solar water heating is not for everyone. If it is too expensive for you then bad luck. Pay Eskom. Most of us would like to drive an expensive German car but not all of us can afford it so we have to do with a fordor a Nissan or even a Tata.
I have a client (household of 4) whom reported a saving of 45% or R300 on his electricity account. They switched off the element and regulate their water usage. My personal experience is a saving of 25%. I have since switch off my geyser and will see in a month or 2 what effect that has.
An alarming amount of customers are Eskom employees. Not a huge presentage but still enough for me to notice. A standard remark is" I work for them and see what is going on" they also have generators.
I always ask a client why do they want to install a SWH just to make sure they would not be disappointed with the thing. Previously about 90% of answers were something about the environment/going green/save the planet.
Lately the reason is to save money/getting rid of Eskom.
Installing is not rocket science as some posters have discovered. It is an easy d.i.y. project. Will take you a Saturday and maybe a Sunday morning. Could save you a few rands and you will know how the system work. I have guided a bookkeeper via email and cell through the installation.( the same oke who save R300 per month)
If Eskom increase their tariffs by 20%+ per year your ROI is more than double that of any (?) other investment.
I have the cheaper Flat Plate Heat Collector available (R3000 - R5000 cheaper than a vacuum tube system) but have never installed one of these. People want the more expensive system.
Watch out for the really cheap Chinese stuff.
Planing to go off the grid?
It is possible but if you think installing a solar geyser is expensive forget it.
And installing a solar geyser is the first step. Then insulate all hot water pipes. Geyser blanket - I don't know.
Next is the stove. Cook on gas.
Use solar energy to dry your clothes.
Use chest freezers and fridges. I have a nice plan for how to convert a chest freezes into a fridge. I see you can also buy a chest freezer with an variable thermostat.
Use the hot water from your solar geyser with the washing machine.
Electrical dishwashers are supposed to use less electricity. I have a manual dishwasher using solar heated hot water and no electricity.
Boil the coffee/tea water on the gas stove.
Switch off all electrical appliances when you do not use them.
Lights? Use low wattage globes. Very nice 12v LED lights are available. But remember the German car? Expensive.
When you have done the above do an audit of your electricity needs and then size and cost a alternative energy system for your specific needs.
Solar is modular so you can work out a plan to go off grid in stages.
My weekend has started.
Thanks Eskom!!
Again I agree with just about everything said in your thread. I, also spend a lot of time trying to explain the "mechanics" in layman's terms. But its all worth it in the end, Why would you need 65'C water if you reduce the temp to a bath temp of 43-45'C, with cold water anyway. Vacuum tubes is for Europe type weather FULL STOP.Hi Guys
I'm also in the business of SWH.
Go for a good brand, Kwikot, Solarhart and have it installed properly or do it yourself properly. There is a lot of energy in 200 litre of water at 65 degrees C, so follow plumbing regulations, the regulations gave been learnt the hard way. I have seen 3 holes blown in house's roofs from botched geyser installations, not to mention rejected insurance claims because of DIY jobs, so please be careful. Replacing roofs, ceilings, cupboards, carpets etc can get pricey.
Water temps over 65 simply reduce the life span of the tank, I always laugh when installers brag about how hot their systems get.
Vacuum tubes are fine for Europe, but not suited to SA condition, they are TOO EFFICIENT. Geysers are designed to vent at certain a temp and pressure, so if the water in the system gets too hot (usually at about 14h30) the safety valve opens and vents basically half of the tank, so you get home to a tank of caold water in the evening. Currently the SESSA ombudsman is facing several hundred complaints almost all of which are vacuum tube systems, so be careful.
Flat plate collectors look like skylights, 25 year lifespan, ideal for our climate. In three years I have done several dozen installations where the client has requested NO electrical backup and 60 - 65 degree water has been no problem. Don't get confused by the whole efficiency of EVT vs Flat plate debate. EVT IS MORE EFFICIENT, but flate plate is better, we are certified to install both so I am totally unbiased. EVT is better for industrial/commercial applications, hotels and guesthouses where hot water is constantly used. Residential application always go for flat plate collectors, at least 1m2 per 100 litres, you won't be sorry.
Budget on R16 000 for 150L, R22 000 for 200L and about R26 000 for 250L. Rebate of about R2 000 for 150L, R3 900 for 200L and R4 700 for 250L.
Go to Eskom website, look under DSM for a pdf list of all accredited installers.
CSIR figures put energy spent on water heating at 43%, generally (almost 400 SWH installations experience) 30% - 40% saving residential and 55% - 60% saving B&B/guesthouse application. Payback is under 4 years, depending on usage. Yet to have a dissatisfied client! My house of 4 runs off a 200L Kwikot direct system, installed by myself when I started my business. It only uses electrical backup on rainy days (I got fancy and installed a rain sensor, from a wrecked Merc), cloudy days, winter days - no problem.
There is a lot of distrust about the solar industry, SWH prices are not going to drop much further and it is the biggest saving you can make per Rand spent. To the clever arse punting RA's, show me an investment of R22 000 that can give you GUARANTEED monthly income of R500 AND SAVE THE PLANET from day one!!!!!! I know, I have installed systems on 4 stock brokers houses, challenge me, I dare you, I double dare you.
Photovoltaics are still exorbitantly priced with enormous ROI timeframes. Wind turbines are only truly efficient on towers 15 - 20 metres high, EIA's and departures from immediate neighbours required in residential applications, so good luck (I currently have 16 clients going through the motions of wind turbine applications). Solar batteries are very expensive, standard deep cycle batteries are reasonable, but require replacement every 5 - 8 years depending on maintenance and charger/monitoring equipment quality.
All I can say is do your homework. Talk to people. Most of my time is spent educating people, I am a treehugger so I don't mind. Call me, PM me, I don't mind.
Just for the record, I know Exactly who the "K" with its factory in benoni and "F" brands is kaybeach007. And once again guys, I am also in this industry and everything this man said is true. Sure we can buy stuff imported from germany and austria, and pay twice as much for something , than we would buying the stuff made in that factory in benoni . I will not mention where their panels come from , because it might upset the cricket and rugby supporters out theirHi TooHotTooHandle
Excellent points you've raised. Let me try and and respond to them.
K brand tanks are locally manufactured in Benoni and mated to an imported collector panel. There are currently no VIABLE collector manufacturers in SA, we are about 18 months from having a locally manufactured collector panel of sufficient quality standards. So there is a carbon footprint, but far smaller than a fully imported system.
Copper requires about 4 times the energy to mine, about 6 times the energy to refine and a host of relatively toxic chemical to refine. So steel is a far lesser evil than copper from an environmental perspective (it's the metallurgical engineer in me speaking). Steel tanks use sacrificial anodes to combat corrosion. We faithfully service and change anodes in geysers manufactured and installed in the 80's and are still going strong, every 3 years we ring up our clients to remind them. Most South Africans don't know that they should change anodes every 2 - 3 years resulting in average geyser lifespans of about 7 years (read that stat somewhere, can't remember where) mainly due to negligence. Bronze and galvanised fittings, copper piping, thermostats and elements all make one big galvanic battery, but if the correct materials are used and installed in the correct sequence (ask old school plumbers about that one) and change the anodes every three years, tanks will last and last. As far as mass production is concerned, the little factory in Benoni does churn out a fraction of the tanks the boys in China do. I don't like glass fibre tanks, the F brand basically destroyed my faith in them, I'll watch their performance over next few years. I don't believe that they can handle the thermal cycling for long.
All solar geysers are 400kPa systems. The lower pressures will mean less stress on the tanks, besides very few municipalities in SA can supply 6 bar pressure. It's usually your houses in valleys that sit with high pressures like that, majority of towns sit between 3 - 4 bars. It costs money to pump at that pressure.
I don't condone DIY geyser installation, but DIY weekend warriors do it and you cannot stop them, but I like to spell out the consequences to them, so that they aren't dissapointed when the insurance company gives them the finger or they scald the baby to death in its cot.
The industry is in its infancy and there are many flybynights out there, which is why we have to try and keep the public as informed as possible. The number of systems coming out of the East and flying through SABS testing is horrifying. Hence the reason to stick with brands you know. The K brand is no silver bullet, but it is a good solid product with a good solid track record (you don't have a 100 year old company that holds a 60 odd percent market share but selling rubbish), made on our shores. Local is lekker.
I have to just mention that this config does not make Eskom happy and they will refuse to pay the rebate to you. In any configuration with an existing geyser, only one may have an electrical element, either the conventional or solar, not both. Eskom do random inspections, so beware, they'll withold the rebate and pull the installers accreditation. I am not a big fan of prefeed systems, they tend to not be as efficient as a stand alone solar system, because the conventional tanks just don't have the thermal insulation that the solar geysers have. Geyser blankets work, but they have their limits.
I agree, this is an good discussion. Education is power.
There is others as well that manufacture in SA, a certain factory also on the outskirts of benoni, make fairly decent panels......But they don't yet compare to imported ones.@ kaybeach007
Thanks for the answer. Many of the points you clarified are not right as indicated below:
-the K branded geysers being more environmentally friendly to a copper geyser??!?(which can be repaired, or turned in for scrap metal when done and generally lasting three times longer)
-no local manufacturer making a viable solar collector??! ( please see www.solardome.co.za = they make ultrasonically welded (onto black Chrome selective coated fin) full copper inner collectors with full aluminum outer casings and low iron non-reflective glass to boot)
Maybe give them a call...