Solar Hot Water ?

[VladTepes]

I have been looking around at options to replace the very old very crappy HWS in our place.

I think the best option is likely to be an electric boosted solar system.

I've come across the following, and would be interested if anyone has comments / experience / knowledge regarding the brand and also the 'evacuated tube' system it uses:

Thermann Electric Solar Te-315-GI-Mld- 30

There is detail on how the system works etc here:
Thermann - Evacuated Tube Solar - Electric Boosted (http://www.thermann.com.au/products/evacuated-tube-solar-electric-boosted)

Thermann Evacuated Tube Heating - YouTube

The full Te 315 / 30 system is quoted at $4196 inc GST but not installation. And apparently there is a rebate of approx $1600 available from the government for a system this size. So they tell me at the shop anyway (Reece)

[jx2mad]

I run an Australian designed and manufactured reverse refrigeration system. Made by Quantum near Newcastle. No solar panels but works great. Jim

[vnx205]

I installed a heat pump or reverse refrigeration type of HWS a few years ago. I also had an earlier heat exchange type for 10 years when I lived near Yass and a Solarhart when I lived in Yass.

I have been pleased with the performance of the heat pump HWS. They have some advantages over other solar systems.

There is nothing to install on the roof. If the current system is outside or even if it is in an enclosed space at least the size of a double garage, installation can be as simple as taking out the old electric system and reconnecting the water and power.

My old electric HWS was inside the laundry, so the water and power had to be extended slightly to get the unit outside.

With one of these HWSs, it can be snowing in the middle of the night and it can still be making hot water. It extracts heat from the atmosphere and doesn't need sunshine.

In the right situations, they can be the most efficient form of HWS.

This is the one I have now.
Dux Airoheat Heat Pump | Heat Pump Hot Water Systems (http://www.dux.com.au/heat-pump)

[DeeJay]

I installed a heat pump or reverse refrigeration type of HWS a few years ago. I also had an earlier heat exchange type for 10 years when I lived near Yass and a Solarhart when I lived in Yass.

I have been pleased with the performance of the heat pump HWS. They have some advantages over other solar systems.

There is nothing to install on the roof. If the current system is outside or even if it is in an enclosed space at least the size of a double garage, installation can be as simple as taking out the old electric system and reconnecting the water and power.

My old electric HWS was inside the laundry, so the water and power had to be extended slightly to get the unit outside.

With one of these HWSs, it can be snowing in the middle of the night and it can still be making hot water. It extracts heat from the atmosphere and doesn't need sunshine.

In the right situations, they can be the most efficient form of HWS.

This is the one I have now.
Dux Airoheat Heat Pump | Heat Pump Hot Water Systems (http://www.dux.com.au/heat-pump)


Is it silent? The heat pump ones installed in Motels etc are quite noisy..

[vnx205]

It isn't silent, but neither is my fridge.

Where mine is located, I can't hear it inside the house. I have a vacant block on both sides of the house, but if I did have neighbours, I bet they wouldn't hear it if they were in their back yard.

The noise is the fan, a bit like the outside unit of a split air conditioner.

I think the commercial ones may have more powerful, noisier fans.

[Mudnut]

I just replaced my HWS 3 weeks ago. I did a lot of research into what to buy, and the whirlpool.net forum au was very informative. I only have single phase power at the house, on gas cylinders, and am shaded a fair bit. What good solar roof space I do have will be taken up by solar panels soon.

I really liked the Therman Solar, but the cost was too much for installation and purchase. I was quoted over 7k up here in FNQ. I ended up with a Stiebel Eltron heat pump unit. Cost a little over 3k installed, and I get almost $900 back from the govt. So $2.2k vs $7k it was a no brainer.

I went with the best heat pump unit available up here. I here there is an Aussie made CO2 gas one with a SS tank, that gets good reviews, but was not available up here.

Rule: Stay away from the cheap ones, as they are nothing but trouble!!!

Good luck,

Ken

[Rurover]

Yep, Evacuated Tube solar is the way to go.
We had a Solahart panel system installed some years ago and as soon as the 5 year warranty expired, the panels started rusting away. (They're only made of mild steel and rely on the anti-rust properties of the ethylene glycol mix in the panels to stop them from rusting).

We then threw away the panels and installed a "Hills Endless Solar" evacuated tube array, hooked up to the original Solahart tank.
The tubes are a doddle to install. Need to assemble a stainless steel frame on the roof, (or not, depending on the pitch of your roof), then bolt on the manifold at the top of the frame, and connect up copper pipes from the HWS tank to each end of the manifold. (Making sure there's an upward slope from the manifold to the tank to get the thermosiphon system working. (Alternatively you have an on-ground tank and plumb in a small low energy circulation pump to circulate the water into the manifold.
Once that's done, just clip in each evacuated tube, and you're done!.

Our system actually operates in parallel with a slow combustion stove in the house. So in winter the stove supplies most of the heat and in summer the evacuated tubes do all the work. No valves or pumps...just sorts itself out by thermosiphon.

Wit the evacuated tube components, there's nothing heavy to lift onto the roof...easily done via a ladder, there's nothing to rust or corrode, the whole thing is frost proof, and it's super reliable, plus more efficient than a panel system.

There are quite a few evacuated tube systems on the market now, so it may pay to shop around and compare prices.

Alan

[DiscoMick]

Better move quickly before the Abbott's Government's inquiry into the RETs results in them being scrapped, which is expected to raise the cost of a 5Kw solar power system by $3000, I read.

Sent from my GT-P5210 using AULRO mobile app

[Jojo]

Hi mate,
how are things? Well, I cannot tell you about this particular brand but the vacuum tube system by itself works great, even at our latitude. Just think of how they will do in sunny QLD... You will have to make sure you get the correct size for your installation, though. If you oversize, you will need something to take off the excess heat. A swimming pool would be ideal for this purpose.
An alternative concept might be to get some photovoltaic panels on the roof and let these power an electric heater for getting warm water. These are a bit easier to steer after demand. But in the end it all comes down to the actual cost, especially if there is governmental funding involved, as some sorts of installation might make you eligible for funding whilst another may not.
Cheers

[Vern]

Apricus! Probably the only hot water service I would install (thermann tanks are made under apricus), I have installed 100 or so of these in either electric storage or gas boosted form. When my quantum heat pump dies, this is what I will be replacing it with, a much better system, particularly in sunny areas. If you go the heat pump route, Quantum is the better of the lot. Down my way, we have pulled out heaps of dux (nicknamed snow cone as it constantly freezes up) and the seibel Altron as well ( early ones were duds, have heard the newer ones are much better).
Research apricus, have had plumber mates install other evac tube hot water systems, all have said the apricus is the pick of the bunch.:)

[bee utey]

I used to have bottled gas instant hot water until the price of propane rose to silly levels.

I bought a Quantum heat pump HWS second hand from a motel proprietor who found the commercial units too noisy. For the first year all went well, the unit being time clocked to come on after dark but off before bed time.

Then the compressor seized. Quantum wanted full access to our credit card before they even put the job order in. Luckily I'm a stubborn bastard and I belaboured the compressor with a 2lb lump hammer every time it tried to restart. 3 days in I eventually won and the unit has been trouble free ever since. BTW the compressor unit is completely Chinese made. Some fragment of metal must have got into the compressor, now it's likely safely away in the drier.

Last summer I added some used Beasley solar water panels aiming at the afternoon sun, and because the house doesn't have any north to north west facing roof surfaces they're on a custom rack. The system controls consist of a 20W electric solar panel on top of the water panels, a special DC pump designed to run off a small panel, and a cheap DC temperature controller set to 65C tank temperature. The panels can't overheat the tank on a 40C plus day. The pump takes bottom water from the inlet junction and feeds it back in the bottom on the other side. That way the possibly cooler water doesn't dilute the hotter water in the top of the tank. It's still useful energy. The circulating pump does not use mains power at all so is cost free to run.

Now on any sunny afternoon the panels heat the water however much they happen to do, and if the tank thermostat is over 58C the heat pump simply doesn't run. On very cloudy days the heat pump runs like normal making sure the tank always has fully heated water available every night. This is an important safety concern because we're on rain water. Everything is fully automatic and needs no regular input from me.

All in all it's a good system but I'd think twice about another Quantum unit. Luckily I got mine really cheap. If the Beasley panels crapped themselves I'd upgrade to some evacuated tube units.

Here's a link (http://www.sideksolar.com.au/) to a company that sells pumped solar units. This system was designed by a friend of mine. I would have bought his controller but he was too late and I built my solar DC system instead.

Here's another link (http://www.ebay.com.au/itm/SOLAR-DC-HOT-WATER-CIRCULATION-PUMP-10watt-/261397322875?pt=LH_DefaultDomain_15&hash=item3cdc7e9c7b) to the DC circulating pump I used on my system.

This (http://www.ebay.com.au/itm/Digital-Temperature-Controller-Thermostat-12V-10A-Switch-40-f-120-f-w-Sensor-/400610014265?pt=AU_B_I_Electrical_Test_Equipment&hash=item5d4637b439) is the temperature controller I used, it's ridiculously cheap and I bought a spare at that price. I extended the temp sensor wire (NTC resistor) to reach the HWS from inside the laundry. The controller gives a permanent readout of tank temperature and it's quick to change the settings.

[sheerluck]

Another Stiebel Eltron heat pump owner here. Installed two and a half years ago, and not a single problem since.

We've never run out of hot water, even when there has been 8 or 9 in the house all wanting showers.

[Phil HH]

I've had a Hills evacuated tube system running for 2 or 3 years now, and it's excellent.
The brochures suggest installing a system that will be adequate in summer, and let the electric backup make up the difference in winter. However I went for a size that would be adequate during a sunny winter, with a collector angle that would increase efficiency in winter and reduce efficiency in summer. The tubes are north-facing and are mounted at such an angle that they are perpendicular to the sun's rays one month either side of the winter solstice.
I have a 30 tube collector and a 300l. tank, and have installed thermometers in the feed and return pipes to the collector as well as the top of the tank. In full sun the temperature rise between the two pipes to the collector is about 15 degrees C. The flow rate of the circ. pump is regulated to 1.25l/min, so it's just a trickle, and takes about 4 hours to raise the 300l. tank temperature by 15 degrees. When the tank temp exceeds about 80 degrees C., the pump cuts out, the water in the collector boils, and steam comes out of the air bleed on the collector. This happens occasionally in the late afternoon of a sunny summer's day.
I installed the whole thing myself, with assistance from #4 son in getting the main collector manifold onto the roof.

[VladTepes]

So there seems a 50:50 between evac tube and heat pump systems nw. Ahh so confusing !

Obviously initial price is an issue but I am looking gor lowest possible ongoing price.... that is, lowest power from grid requirement.

[Mudnut]

I figure solar is more economical in the long run, but about $5k more to install (up here at least). In my books, if I use that $5k on solar panels and install a 5kw system, should be well ahead in the long run as far as power consumption, and grid usage. Plus I have limited prime roof space for solar usage, so might as well use it for generating electricity.

Cheers,

Ken

[Jojo]

So there seems a 50:50 between evac tube and heat pump systems nw. Ahh so confusing !


There is no reason why you should not be able to combine these two. You will need a decent accumulator tank, but that's god to have anyway.

[Vern]

Look at it this way, heat pump, too many moving parts, compressor, gas, fans, evaporator etc.... evac tube, a 40w pump, the rest is standard hot water bits, ie element and thermostat.
If your in a sunny warm environment, you can leave the system turned off for may be 6 months or more, and you only have a 40w pump running.:)

Oh and as I said, I have a heat pump.

[jx2mad]

I know what solar panels are but what are evac tubes? Jim

[VladTepes]

Have a look at the link in the first post it has an explanation

[Tombie]

So you dont have Gas mains?

We looked deeply into replacing our Instant Gas Hot water (Rinnai) with heat pump tech...

Did the sums and came to the conclusion the Gas was cheaper...

Unit cost substantially cheaper, Gas bill is sub $100.00 a quarter including supply charge and this provides Hot water and Cook top.

Not saying this is for you...

[rovercare]

If you just willy nilly replacing your hot water to "save" money it may not necessarily be the case

I could not get the return on investment to work well to install an apricus how water, unless I could calculate in replacement costs of my exisitng hot water service, ground mount electric unit

Apricus do an excellent job, far better in lower latitudes of aus, if I was to live in the northern end of the country I would simply use a flat panel system, as the abundance of sunlight year round makes up for the lack of efficiency, down south, evacuated tube ONLY

Keep in mind, azimuth/inclination of installation is a big factor in performance, especially the further south you are

Personally I am waiting for 2 things to hit the market to trial run, 1 is an immersion controller from wattson and another from immersun, both currently available in the UK, this units monitor your import/export and as oppsoed to exporting will use your solar to heat water, this I will trial on a few exisitng customers places and I think will be a real set and forget winner

Others on exisitng feed in tariffs, or small install capacity area's there is another unit coming from NZ that is a stand alone inverter for your hot water unit, which comes with auzillary contact setup that allows night/day rate boost if required

I believe there is great merits in keeping a ground mount tank as opposed to a unit with sensors and pumps and even more so, heat pump systems with a compressor unit atop, as there is only 3 failure points on the standard hotty....thermostat....element....tank, even the most basic of electricians can fix 2 and will usually stock the parts in their van, so this saves alot on future repairs, whereas the other units will take more knowledge, time and effort to diagnose (and most likely wont carry the spares), which means dollars in the future, this soon blows your return on investment out

Although, again if in the northern end, flat panel system with rooftop tank also eliminates all these parts and makes for a simple reliable system

Bottled gas is silly, I sell them aswell, now $143 a bottle, gas prices have reason $20 a bottle since i took over the bottles maybe a year and a bit ago and I'm tipping they wont ever get that low again:D

So if you really insist on quality unit and not up the north of the country, buy an apricus system, just make sure to get it installed to the correct azimuth and inclination as per the apricus manual, for best effect in winter

[101RRS]

I cannot comment on the required system but there is one aspect I have experience with and that is the booster on the solar system. Most are auto so come on if the water temp gets a bit low but the water temp is still Ok for most uses for a little while and often the sun comes back before the temp gets too low so the electricity/gas used in heating the water is wasted.

The system I had years ago had a switch in the house for the booster, off, one and auto. I had it always set to off and 99.9% of the time the water was always hot enough and it was only after a few cold rainy days did I have to turn it on. You soon learn when to turn it on.

Now you can leave it on auto but I found having it off and turning it on manually only when required saved even more energy.

Cheers

Garry

[VladTepes]

Def leaning toward a evac tube system with ground mount tank. The question is which particular make / model to go for.

As far as our existing system is concerned - its 20 years old and on the way out according the bloke who did the pre-purchase inspection. Now is a good time for me to buy as I have a few $ left from the settlement of teh previous house (should go on teh mortgage but I do like hot water... :lol: )

[vnx205]

If you have a system that uses an electric boost, then how you use that boost and when you use your hot water makes an enormous difference to how much benefit you get from the solar heating.

When I lived in Yass, we installed a Solarhart and while it was a good unit, I was never able to persuade SWMBO to use it to best advantage. The ideal way to use it is to use most of your hot water in the morning so that there are plenty of hours of sunshine to bring the water back up to temperature for evening hot water use. If the day doesn't provide enough sunshine, then judicious use of the boost can bring the temperature up enough for a hot shower before bedtime.

No matter how many times I tried to explain that, SWMBO did everything in reverse. She used a lot of hot water late in the day and then ran the booster all night so that there would be hot water for the morning. By the time the sun came up, the water was already heated, so the solar contribution was minimal.

In some circumstances, it can be a bit inconvenient to regulate the way hot water is used, but if you can get it right, it makes a big difference with that sort of setup. With the heat pump HWS, that is less of an issue.

[rovercare]

If you have a system that uses an electric boost, then how you use that boost and when you use your hot water makes an enormous difference to how much benefit you get from the solar heating.

When I lived in Yass, we installed a Solarhart and while it was a good unit, I was never able to persuade SWMBO to use it to best advantage. The ideal way to use it is to use most of your hot water in the morning so that there are plenty of hours of sunshine to bring the water back up to temperature for evening hot water use. If the day doesn't provide enough sunshine, then judicious use of the boost can bring the temperature up enough for a hot shower before bedtime.

No matter how many times I tried to explain that, SWMBO did everything in reverse. She used a lot of hot water late in the day and then ran the booster all night so that there would be hot water for the morning. By the time the sun came up, the water was already heated, so the solar contribution was minimal.

In some circumstances, it can be a bit inconvenient to regulate the way hot water is used, but if you can get it right, it makes a big difference with that sort of setup. With the heat pump HWS, that is less of an issue.

Trying to convince your wife to alter her complete lifestyle is not a smart idea :D

What you would be best of doing was switching the electric boost off until your were running out of hot water, matter of fact this is a must when it comes to manageing your system and actually saving money

[superquag]

vnx, I feeeel your pain...:( - have similar in our household...usual sin is running the dishwasher (complete cycle including "drying") in the daytime, -when our PV array is doing it's best to earn 47 cents per unit. Night time we buy it back at 22cents.

Our SHWS system runs with the booster switched OFF for 99%. Winter time we go back to the gas instant for showers, and leave the solar to build up heat over several days.

[DiscoMick]

My wife defers everything until the night so we get the full solar rebate during the day.

[vnx205]

Trying to convince your wife to alter her complete lifestyle is not a smart idea :D
Yes, I learned that it was quite unproductive and quite inadvisable to even try. :)
What you would be best of doing was switching the electric boost off until your were running out of hot water, matter of fact this is a must when it comes to manageing your system and actually saving money
I tried that, but she knew where the switch was and it just seemed to be part of her evening routine to switch the booster on even if I had previously switched it off. :D

[superquag]

Put a big hairy spider in the meter box....:twisted::twisted::twisted:

[Bigbjorn]

We replaced our off peak electric storage 20 gallon Rheem with another similar size. Cant see the point in spending $5000 or more to replace a $1,000 system that costs very little to run now there are only the two of us here. Our total electricity bill is under $180 a quarter.

[VladTepes]

I thought all new HWS had to be solar or heat pump or gas. DIdnt think you could have just the regular 'old' kind any more ?

[Vern]

You can still buy them, but you are better off buying a solar ready tank in case you wish to adapt solar to it later. Thermann sell these, about $100 more than a normal tank from memory