A question from a Sydney Central Branch visitor I am sure someone here can answer.
Mathilde asks
"Does anyone manufacture an Evacuated tube collector with a 300L (or so) capacity tank, coupled to it on the roof ?"
I would also ask why this question is even raised is there a technical reason why she has found it difficult finding and installer or company who could meet what sees to me to be a simple request.
Thanks In advance Tony
cool at home
Member
Run on Sun go up to 250L... I don't know anything about them, just noticed their ad once.
And I think it wise to ask why passive systems with ET collectors are so hard to find... I'll be interested in the answer too.
http://www.runonsun.com.au/www.runonsun.com.au/Passive_evacuated_tube_solar_hot_water..html
They are hard to find because it is expensive for an importer to get certification according to Australian standards. And without standards -> no rebates -> no markets.
I also cannot see much advantage besides saving pump and controller.
matas
Member
"Does anyone manufacture an Evacuated tube collector with a 300L (or so) capacity tank, coupled to it on the roof ?"
Here is a 300L one for $1250
http://www.fxlarkin.com.au/page105387.cfm
Not qualified for rebate though.
Ben1
Member
sun2steam, one thing that appeals to me about close-coupled SHW systems is that they don't rely on electricity to operate. You could live through a week-long blackout (eg. in Qld) and still have hot water (provided there is adequate insolation).
Lance
Key Master
The main reasons behind the prevalence of split systems, apart from that mentioned above, is that split systems look better (no tank on the roof), easier tank maintenance (not really an issue if you fit a stainless steel tank) and that many modern roofs don't have the strength to hold a tank full of water without reinforcing, which adds to the cost of installation.
However, split systems have lots of drawbacks and far lower reliability compared to thermosyphon systems. We hear of lots of cases where split systems stop producing hot water after only a year or two, mainly due to pump and controller/temp sensor failures. The owner often doesn't notice there's been a failure unless the pump jams on and keeps running continuously, or they get a nice whopping increase in their energy bill due to constant boosting being required. Or, with evac tubes, often the tubes will overheat and start making scary noises, just before they shatter.
In short, while they are not as pretty, thermosyphon systems are more reliable. If you can mount them in an easily accessible place, on a ground frame or whatever, more's the better. I personally wouldn't have a split system, being a fan of the KISS principle. Anything overly complicated just for aesthetics really bugs me, I hate it when form takes priority over function...
most of the china systems are gravity feed systems so are open vented the water will boil and vent to atmosphere this is your method of controlling the heat @ 500 kpa the water will get to over 150c so must be controlled by the sensor and pump system eg split system or downsize the system and boost when required this is how solar systems are designed high solar gain in winter with boosting as needed and not overheating in summer its not rocket science.lance wich brand off tubes makes scary noises just before they shatter I have sold thousands of tubes and never heard of this happening I am in Townsville so I consider that the tube systems that I sell will have to survive some of the most extreme weather conditions you can throw at them and the biggest issue I have had is where some plumbers think they know more than the system designer and dont follow the proper install instructions. During the recent blow and rain none of my installed systems have failed to perform ,some dont even have the booster installed, customer choice but no complaints The truth doesn't sell very well but at the end of the day I have a lot of happpy customers who all have enough hot water for their needs.
Kiss is good but add to the 400 kg on roof system weight of 250 mps wind load and split system suddenly looks good easy and cheaper. every system is and should be designed for location and sized for needs of individual homes and hot water usage
shop around get informed and make the right choice(Mick)
Buzzman
Member
Rinnai have a close-coupled thermosiphon of 330L
http://www.rinnai.com.au/index.php?option=com_products&task=categories&Itemid=2&cat_id=33
MKK
Member
Thank you all for the suggestions. Down to the basics. In 1982 I installed 2 Rheem solar hot water systems, each about 300lt on a normal tiled roof. Flat panels of course. Jump to 2011 I would like to install a 300lt ss tank with ET's on the roof on a new house, not yet built. I know it isn't as pretty as a nice clean line but it makes good sense to use the KISS system and eliminate the need for two unnecessary parts. If a roof could take a 300lt tank then, what makes it so hard today? Reinforcing if needed can be designed in so that will not be an issue. I don't believe the ET system would weight that much more than the two flat panels in 1982... Is there a reason that makes sense why I can get all rebates for the same sized flat panel system but not a close coupled ET system?
mick_queensland
Member
Hi, I have been re-reading posts trying to gleen any more useful info from them as I continue my search for a SHWS. I would like to agree with Amun-ra regards the point made about modern roofs holding the weight of a water tank without extra bracing. My ideal system would use a tank on the roof and thermosyphon (KISS) as we have heard, however, to do that on my 10 year old house which is in Townsville and built like the proverbial, I would have to (by law) get an engineer to design bracing to increase the strength to take the weight of the tank. I know this because I actually contacted the engineer who designed the roof trusses for my house and asked if it would hold the water tank. So, all those lovely KISS systems are out for me, unless I get an engineer and a builder back before I install the SHWS. Now a Split system is looking really attractive hey.
Cheers, Mick (by the way, not the same Mick as Amun-Ra either)
yabbietol
Member
Hello I am new to this Forum and have watched this discussion with interest.
I have a 11year old 300L Edwards Flat Panel System on the roof of my house in Queanbeyan NSW which works fine in summer, but needs lots of boosting in winter. The water supply is tank water with pressure pump. I was looking at replacing it with a roof mounted evacuated system. I have had quotes for split systems that even with rebates (though I am not eligible as I already have a solar HWS, dodgy installers said don't worry we will fix it, wink,wink) that come out at around $4000 to $5000 after install minus rebates. My two concerns are, I am honest and do not deal with crooks and the quotes were way too high and all required extensive plumbing modifications plus pumps, etc which would increase the risk of system failure.
I would like to simply replace my existing 300L Edwards system with an evacuated tube system including install for around $2000. The price to replace the Edwards flat panels from the local agent is $1700 each panel, as I need two. This is $3200 to replace a product that as soon as the warranty expires delaminates its solar absorbent coating and has required considerable boosting through its life. Yes, I have repainted on panel as an experiment, which did improve performance, but I would like to reduce boosting and get away from a product that performs poorly in my climate in winter.
The internet shows several Chinese import Evacuated Solar Hot Water systems, which are all stainless steel with 20 to 30 tubes for under $1500 (which is less than one Edwards replacement panel). These look attractive as I have an existing solar hot water system and not eligible for most rebates. All I need is a quality system as described below. If my roof can support a 300L Edward's system for 10 years i am sure it will support a replacement 300L system (appearance is not critical, as the roof also has 2KW of panels and various antennas, vents, chimney, etc).
Evacuated tube system with 30 tubes mounted at 55 deg (roof slope 20 deg plus stand to add 30-35deg)
Stainless steel tank
Electric booster heater in tank.
Fitted on roof to replace existing Edwards system (hence plumbing and electrical install simple extension of existing pipes)
The most difficult of all a reliable honest installer in the Quenbeyan and ACT area who would charge a reasonable price for a days work and to fit the new system to replace the old system.
Please let me know of any suitable systems that can be purchased installed for about $2000 (not unreasonable as plumbing needs minimal modification unlike split systems). Or even better an installer or company that does good work in my area.
yabbietol
Member
This is brief follow up on my above post.
Even if there is no reliable installer in the Queanbeyan or ACT region does anyone know about reasonable priced evacuated tubes systems that can be fitted on a roof as a replacement for an inefficient Edwards Flat Panel system?
Also it would be good to get ride of the ethylene glycol in my existing system.
Also I forgot to mention we regularly get below zero in winter (we are at 800m) so tank needs good insulation and the system rated for minus 10 to minus 15 deg C. So it would need freeze and frost protection.
yabbietol
Member
I have ruled out split system on install cost due to extensive plumbing modifications and overly complex operation that requires circulation pump, multiple sensors and controller all prone to failure.
The split systems such as Hills and Apricus are over priced and too technically complex compared to evacuated tube systems with tank on roof. Following forums on the ATA website, split systems do not appear to perform in reliable a fashion people are always having problems with pumps or controllers and poor install. The simpler system the less likely that the install will be messed up.
Spilt systems and Flat panel systems cost twice as much as they should in Australia. If it was not for subsidies not many would be sold. I bought my Edward's Flat panel system 11 years ago with no subsidy on principle to reduce our impact on the environment and have always been unimpressed by its winter performance, hence looking towards better performing evacuated tube systems, but not at the expense of increased complexity and overpriced systems. All I am looking for is fair value and reliability , which can come from simple design such as the systems for under $1500 on ebay.
peter69_56
Member
yabbietol said:
I have ruled out split system on install cost due to extensive plumbing modifications and overly complex operation that requires circulation pump, multiple sensors and controller all prone to failure.The split systems such as Hills and Apricus are over priced and too technically complex compared to evacuated tube systems with tank on roof. Following forums on the ATA website, split systems do not appear to perform in reliable a fashion people are always having problems with pumps or controllers and poor install. The simpler system the less likely that the install will be messed up.
Yabbietol,
Whilst I agree most if not all of the solar products in Australia are over priced. Its the same with many other products such as sucba diving gear etc. Not a lot we can do about that other than to buy overseas and import. As far as bad installations, it doesnt matter which system you get, the install can be bad or good soley depending on your tradie and their proffessionalism.
I do disagreee with your comments about the split system being overly complex in operation. There is 1 pump and if of quality is normally not likely to fail early. In regard to the controller it has usually 2 or 3 sensors and the good ones show you whats happening if you look at them (and have had it explained by your tradie). If controllers fail, it usually is bad installations such as wiring badly run or sensors not installed. In the main they work as well as they are installed. I do agree that the roof mount is simple. As far as plumbing its not a huge change for a plumber, just a runof pipes and not hugely expensive (unless you are ripped off). In the main they do work well and do not constantly fail as you suggest. What you see on this site are people who have problems, what you dont see is the majority whose systems work well and continue to do so. They are the silent majority.
I think you are set on a roof mount and I do understand that we all have our preferences. I myself prefer split systems, mainly because its neater and no weight on the roof and easier to service. In saying that I see no real disadvantage on a roof mounted system either except to service them. Each to their own I think.
I too like evacuated tube over flat panel as a preference, although I do recognise that they both do work well(depending on location)and have their good and bad.
I do take your point that getting an evac tube roof mount in the size you want. We are constantly being raped and pillaged as consumers in this country. No one will do anything about it as there are too many making huge amounts of money from it. I think its called "GREED". When I can import an item from "any, and I do mean virtually any" other country in the world (and not necessarily asian countries, but 1st world countries) on a one off, and pay half the cost of what I would pay here including the postage, it so smacks of "GREED here with little good competition and an ability to either manipulate pricing or come to a common agreement between large companies to "fix" pricing (and please dont tell me this does not happen as I have seen actual cases of price fixing in industries that have draconian laws by governments to prevent this from happening).
So I sympathasise with you and hope you find what you seek however I would not hold my breath. As consumers we have to take what we are offered most times.
Ueee
Member
If you dont want to get one off ebay, try fx larkin http://www.fxlarkin.com.au or run on sun http://www.runonsun.com.au/
yabbietol
Member
Thank you Ueee and peter69_56.
I think peter and I should agree to disagree about the reliability of complex systems, but we certainly agree about over priced systems.
I am not locked into roof mounted systems, but they do appear to be simple and the most reliable while being efficient. I also agree about evacuated tubes seem to be more efficient than flat panel.
Thank you Ueee the run on sun look interesting, the FX larkin have notes about not been usable in areas with frosts not sure why, but that would eliminate them from potential systems in my area.
Russell Moore
Member
I am seriously thinking of installing one of the ebay Chinese close coupled et systems on a rental property I own in Sydney. Has anyone actually installed and used one?
Also is there anywhere in Sydney where I can buy one? I'm thinking of a 30 tube system.
Skysolarman
Member
Hi Matas ...fxlarkin system is a water in tube system meaning it is a low pressure tank and if one tube breaks its all over...hot water everywhere...dangerous...
dixiemelody2003
Member
Hi LaSource: have a look at http://www.solaroz.com.au, they have the type of systems you are looking for. Just found them myself, so don't yet know what quality they are or if the company is a good one, but worth a look. I emailed Skysolarman for info about his offer to supply a system like this, but got no reply, even though I know he received the email, so don't quite know what is happening with him or whether his offer is genuine or not.
raklink
Member
Hi Yabbietol
I have one of the ebay chinese hot water systems.
Great feeling of having hot water most of the year at no cost.
Has helped us lower our average daily power usage to just over 5kwh (family of 4). With our 1,8kw PV system, we are always in credit with our PowerCo
Based on installed cost of just over $1100 (DIY), the fast Return on Investment (ROI) makes SHWS a no brainer. Whilst no where near as trendy as PV, SHWS should always be implemented first based on its' higher ROI.
Details on unit/install here.
http://klinkfamilyadventures.blogspot.com.au/2011/01/solar-hot-water-heater.html
I was keen on the Closed Loop Thermosyphon units due to these advantages
1) No pumps / moving parts to break
2) No energy required to run. Uses Thermosyphon effect to circulate water
3) No legionaires issue as mains water is separated from tank water via heat exchanger (ie copper tube windings in non pressurised tank).
4) Easy to post boost water temp with instant gas units (Rinnai/Bosch etc)
5) Cheap to buy bits
6) Plumbing points to connect to wet backs
7) Very simple to setup and maintain.
Other points
1) No rebates available - Less of of problem now a days with the winding back of most government incentives. Not a problem to me as I find rebates are hardly ever relevant ROI wise when you approach these projects from a DIY perspective.
2) I like the flexibility of being able to maintain unit myself. Also, as you can see from my blog, is a great learning environment for both my son and daughter.
3) Definitely NOT maintenance free (unlike PV) - I have had hail damage, burnt out heating element, leaking silicon gasket. Simple/cheap fixes but would be expensive if I had to call plumber etc
4) Weight (say 300kg plus). Make sure your roof can support !
5) Cheap bits - I had 7 tubes break in melbourne xmas day storms - cost $10 each to replace
6) Need to be a bit careful re very hot days. The unit will easily boil on a 35+ degree day. No risk of explosion as unit is well ventilated, however, kind of wasteful (venting) and makes our tin roof rumble (note to self - next time install some rubber shock absorbing under mounting timber). Answer for me is a Heath Robinson style shade cloth system to half cover the unit on hot days.
Please let me know if you have any questions.
Littlehouse18
Member
We are seriously considering installing a Rotex split system with evacuated tubes in a new build house(http://en.rotex-heating.com/products/solar-system.html). Not withstanding the general comments above regarding complexity, it is another evacuated tube product that doesn't appear to have been covered above and we have been impressed with the design and specifications of the tanks (300L and 500L models). I haven't heard of a version with the tank on the roof.
Hi, just joined, but I have a LOT of experience with this.... I can see Lance's point about the KISS principle, I too am a firm believer in it. HOWEVER, a well sited split system, as ours is, will NEVER need boosting. We have never boosted in about seven years. http://damnthematrix.wordpress.com/2011/09/04/the-power-of-energy-efficiency/
Roof mounted tanks lose a lot of heat overnight if you are in a cold climate. (we're not, but we did have -6C one morning a few years ago!) If you think in terms of ENERGY, that heat loss is far greater than any electricity you may use to power the circulation pump.
Re reliability, I believe it pays to buy a better brand. Ours is a Beasley (now Rinnai) and the pump they use is a German Grundfoss which I am led to believe are the Rolls Royces of pumps. Ours has worked flawlessly for seven years, though I am thinking of buying a backup one for when TSHTF and they may become unavailable. When you think about it, they are not exactly stressed, as they have no head load on them (there's an equal amount of water pushing down as the pump has to lift), they don't spin at high revs, and there's no reason why they shouldn't last a very long time....
Mike
yabbietol
Member
I have yet to make a move with my roof mounted solar hws, but a recent experience has emphasised with me a benefit of roof mounted systems that I did not previously think of, during the recent floods in North Wagga I was involved in cleaning up houses with the NSW Rural Fire Service and a common problem was that hws were damaged by the flood waters. Roof mounted systems were not damaged while ground position tanks were written off. If you live in a potential flood affected area think about roof mounted systems.
If you live in a potential flood affected area, shouldn't you just MOVE?
Russell Moore
Member
Or build up on poles, or on floats?
