I am interested in the difference between the running costs of the two types, has anyone here changed from off peak electric to an LPG instantaneous hot water system.
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I am interested in the difference between the running costs of the two types, has anyone here changed from off peak electric to an LPG instantaneous hot water system.
The difference would vary from state to state as electricity prices vary accordingly. If it was me I'd be staying with off peak electric.....this gives you the option of using PV solar to power your hot water if you decide to do so in the future.
Hi Chris,
I haven't done this personally yet but have been seriously considering it. I currently have a 5KW solar which gives me 44c per KW return from Ergon but this would reduce to 9c KW if I put batteries in or change anything so Im still on the fence about batteries.
Over a 12 month period my son went to a 5KW solar system with a battery system and then converted his HWS to Instant Gas and put in a Gas stove as well with the larger bottles of gas and even has his gas BBQ plumbed in. These large bottles last him for several months and are relatively cheap to have refilled. He has 2 young children and as a family their energy footprint is very small as a result of these changes. He has no regrets and and is extremely happy with what he has done and would do it again in a heartbeat. Oh and in QLD off peak electric prices have been slowly increased and now are worthless as a tariff and in my opinion are not worth having.
The son had a lot of help and info from a local company called Super Green Solutions (usual disclaimer) and I am sure there is probably someone similar near you who has the info you need. He has also gone 100% LED lighting as well. His power costs are minimal and the Gas part of his system is in his words, Awesome.
Hope this helps.
Cheers, Ian
Chris Parks
Have you considered a third option: hot water produced by a heat pump? I don't know the technical term but, in effect, that's what it is.
The system I have is a "Sanden". The gas in the compressor is CO2, which doesn't need special treatment in the event it is replaced. The capital cost of the system - installed - was approx $3.6k. For a household of 2 people, our three-monthly power bill for our hot water hovers between $30-$40 which includes a "statutory" daily charge. (There is a separate tariff for hot water power consumption in Tas). The friend who mentioned this system to me has a similar unit and his own bill - for 2 people - is in the same ball park. All this with the usual disclaimer re interest etc etc.
Cheers Yvan
We have off peak here and a 5 kw PV system helps out with the electricity bills.
A previous residence had a heat pump system and it was comparable to off peak.
Years ago my brother had gas and found it to be expensive.
I think Ian has the right handle on things.
Don't ignore the solar boosted systems as well. The new technologies apparently are so much more efficient than the old pipes on black that I have. A plumber friend of mine installed one and he said that they work remarkably well, even on overcast days.
When mine packs it in that is where I am going. (I don't have reticulated gas).
John
Been there and done that years ago. We had a Siddons(?) system and it started to become ineffective due to shadowing and finally went when we had a large renovation done. My issue with storage hot water of any kind is why pay to heat water you never use and also lose heat before it gets used. I looked at this when doing the reno but things were on a tight dead line and I had to abandon the idea at that time.Quote:
Originally Posted by yvan
Converting an off peak electric hot water to LPG is not a viable economic proposition. Rather than spending your money on a new system and installation costs, with the low feedin tariffs offered, you are financially much better off if you install solar electricity panels with a diverter that diverts any surplus electricity into your hot water system while still giving you the benefits of solar power.
If you already have solar electricity add some extra panels, install a diverter and reap the benefits.
With my system I only have to turn on the off peak during the middle of winter during heavy overcasts.
The cost of solar panels is reaching a point where a set of dedicated PV panels connected to a heat pump hot water system may end up cheaper than a solar hot water system.
We needed to get rid of an electric storage heater soon after we moved here on the Mornington Peninsula four years ago, and replaced it with Rinnai 26 instant heater inset into the wall with a cover. Neat unit, no problem, it disappears into the wall on the deck.
We have LPG central heat which we very rarely, if ever use, a 6 burner cooktop and the hot water on LPG.
Just 2 in the house, but we often have kids & grandkids here. At this time of the year I love the long hot showers. The water is free, 'cause tanks (75,000 litre) are overflowing
We have a fat boy 210 Kg bottle. It was filled Oct 14 2015, and again April 20th 2016.The April bill was $213.65 for 231 litres for about 6 months, and yearly rental on the bottle is $200.00
Big saving on filling my own BBQ bottles compared the exchange bottle. I just take them back for exchange if they go out of date, or fail the soap water test.
Don't know about other ways to do hot water, so can't compare current pricing.
Cheers,
Peter
Thanks Peter, that is something to work on.
I'm looking at replacing our hot water system too in the next few months (when we've got some money!). We've got a large solar system at home and I want to use that as the energy source. In the future I will implement a battery solution to store power for overnight use, so that we can reduce our grid power usage even further. I'm currently looking at a solution that is branded Sanden. They seem to use a heat pump technology similar to a reverse cycle air conditioning system, and claim that it is very power efficient. Looks like a decent solution. I'm going to look at these heat pump type systems.
Another alternative to consider - we've had one of these heat pump hot water systems since the house was built 12 years ago:
Quantum Energy Reliable Hot Water Systems | Heat Pump vs Other Water Heating Methods
We've found it really does use as little power as they say. Looks like a standard electric storage water heater, but with an extra bit on top. No roof panels or extra plumbing required. When we bought Quantum were one of very few in this market, but since then several other companies have come out with similar units. Google "heat pump hot water service".
In South Australia since 2012 high efficiency (=heat pump) electric hot water systems have been mandatory in new residential dwellings and when replacing an existing hot water unit. They're definitely more energy efficient than a resistive element system......think comparing a two bar electric heater versus a reverse cycle air conditioner.Quote:
Originally Posted by Poppa
Energy prices here aren't really directly comparable (I think, not 100%) but basically hot water in Japan is almost always the instant gas variety. Have never seen an electric hot water tank. Not having nanny-state laws, limiting output to 40 deg C delivering tepid at best water where you need it, they are great. We have a rental unit in Aus that has one of those heat pump systems. How do you quantify the energy savings vs the high cost of repairs when something goes wrong? We were told we needed a new fan last year. After costing it, I told the agent it would have to fail completely and deliver no hotvwater before being replaced. Nice idea, but too expensive to buy and maintain.
What's to go wrong? A heat pump is basically a refrigerator in reverse. Ours has outlasted any other conventional water heater we've had at any house. Zero maintenance, zero problems in 12 years. Mind you, Quantum have probably the longest track record with heat pumps - maybe some of the new makers on the block have issues?
Electric powered storage hot water systems probably rare in Japan because of the space they take up...space at a premium in most Japanese residences. Electricity is also generally more expensive in Japan than in other countries...even more so now alot of it's nuclear power plants have been shut down post Fukushima.Quote:
Originally Posted by q9
I think Siddons have been at it longer than Quantum, we had a Siddons heat pump system installed about 30 years ago. They now have what they call a bolt on system that uses you existing tank and I presume that the element in that could be used as back up if necessary. I might give them a ring and have a chat tomorrow.Quote:
Originally Posted by Mr Brush
Well there is a fan for a start... replacement cost over $400.
Dunno where you get your idea that electricity is expensive here. It is about 11 yen/kWh. When I left qld it was hitting 17c
Oh, and last time I had a gas connection in Australia, I had to pay a daily connection fee, regardless of use. Not the case here. You get reamed in Australia for energy costs. Not looking forward to going back...
The nice thing is that when our solar system is powering the house it will provide the electricity to power the heat pump hot water system. And when I get batteries they will provide the electricity overnight. From looking at brands I'm thinking Siddons or Sanden. Might be expensive to install, but I have a hankering to use our solar to power the entire house (eventually, when we get batteries).
I made the switch from off peak to a Rinnai about 10 years ago after the off peak died (water everywhere). We have noticed a drop in our power bill but that wasn't the only reason we did it. We now have the option of gas heating and cooking and/or electric heating cooking. This is important as we have long blackouts in our neck of the woods when the east coast lows hit.
I can't see the logic of re heating water I've already paid to heat the night before.
TT
RE- - the quantum system, just had one installed(in the last 6 weeks) for around $600 all inclusive(supplied and installed) there is some government rebate thing going on, to replace the regular hot water storage systems, it is not heavily publicized but worth looking into. It will be interesting to see the next power bill.
Have a look at the vacuum tube solar systems. We put one on the roof of a three bedroom house in 2013. Cost about $2400 all up, 200 litre hot water storage, mains pressure, works all year, electric backup hardly ever kicks in, perfect for a small family. These things are miles cheaper than anything else. I am looking at putting one as a preheater to our gas water heater at home. It will be very cheap to install because there will be no electrical connection and the plumbing will only be re-routing the cold to the gas hot water through the solar. The one I am looking at has a 200litre reservoir of hot water at atmospheric pressure and the mains pressure cold supply runs through a big coil in the hot water and gets heated up. If you do go this way don't get the ones that have the hot reservoir separate from the vacuum tubes because they rely on a pump and the pumps keep breaking down and are very costly to replace. Go for the ones that have the reservoir on the roof attached to the vacuum tubes.
Funny someone mentioned the 'nanny state' and 40 degree water...the water coming out of the one we put in was literally boiling and quite lethal so tempering valves are compulsory which mix in cold water and bring the temperature down to about 65-70 degrees C. Still hot enough to get a first degree burn but not the instant second or third degree burn you would get from the boiling water.
I have one of this kind, they work extreamly wellfor heating water, but as there is no way to stop them heating the water in summer. When they boil they dump boiling water to replace it with cold water to cool the tank. With a horizontal tank they dump a huge amount of water to cool off and can dump several times a day. With mine I plumbed this water back to a storage tank to avoid loosing a lot of water.Quote:
Originally Posted by Toymaker Len
Not all evacuated tube systems do that. Mine certainly doesn't. Just got through winter hear with a total water heating cost of $6 for the off peak booster power used. So that's the total annual running cost. Absolutely awesome! The circulation pump runs on solar power and the panels are angled very steeply to optimise winter heating. Its never dumped water, though does get to 186 deg c in summer so tempering is needed.
Bodan you just cover them a little with some shade cloth or bamboo screen or something. They are ferocious little beasties when they start spitting boiling water eh?
Tempering valve.... I fail to see the point of heating the water then cooling it again apart from protecting children and the aged/infirm. We've got a tempering valve in the guest room HWS which only gets turned on when we've got guests. We asked the plumber not to fit one in the main HWS when we built the house. I got the sparkie to turn the thermostat down to 50C and fit a timer in the circuit. The timer comes on for a couple of hours in the afternoon and can be overridden when necessary.
Geoff.
Geoff,
Holding water at <60 deg C is a breeding tank for bacteria, like legionella. A dangerous beastie. See:
Tempering Valves - Hot Water Mixing Valves Explained | ELGAS - LPG Gas for Home & Business
Heating up, then mixing back to a usable temp is not much hassle, and may save you or your guests a nasty illness.. I make sure my system hits 70 degrees every 24 hrs. Mostly this happens with the suns heat, but the thermostat will kick in at night if needed to ensure the bugs are dead and not brewing. I'm pretty sure this is a legl requirement in most states?
Thanks Elver I hadn't thought of the risk of bacteria in the water and is a concern as we're on rainwater out here. I think I'll turn the thermostat back up. Thanks for the info.
The guest room has a separate 50L HWS because it is down the other end of the house, keeping the plumbing runs as short as possible to avoid running it for 5 minutes waiting for the hot to come through, it has got a tempering valve installed.
Cheers,
Geoff.
I'm fairly certain its mandatory now to be fitted on a hws. Atleast in qld I'm certain it is.Quote:
Originally Posted by Boringgeoff
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Bebbo I think it is mandatory also in WA. We instructed our plumber not to fit one. Our previous house built in 1978 didn't have one, in fact in the 70's in Karratha you could barely get under the cold water in the middle of summer.
Geoff.
Geoff you don't need a tempering valve if you have a system with a thermostat, ie gas or electric but the solar, particularly vacuum tubes, gets really really hot. The sort of hot where granny is bathing the two year old, gets distracted, the two year old knocks the hot full on, slips over and gets blasted with 120 degreeC water, spends a year in hospital and lives with the injuries for life. The tempering valve doesn't bring the hot water temperature back down, it simply adds cold water at a controlled rate so much less super hot water is used.
I built a block of unitd and spome directly with tge hydraulic engineer and the building certifier and both said they all need tempering valves.
I would only assume a thermostat would suffice. The hot water must be within a certain range of temperature so however you limit it aslong as you limit it it was my understanding that its fine then.
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If you instruct your plumber to leave out the tempering valve then he needs to make you sign a written instruction to do so. If an accident happens and the lack of the tempering valve is found to be a factor then your poor old plumber will be the one they go after.
Even that will probably not protect him.Quote:
Originally Posted by kiwigeo
Most likely not....Quote:
Originally Posted by AlexS
A letter won't decriminalize professional negligence causing actual bodily harm.Quote:
Originally Posted by kiwigeo
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No one is going to get scalded in my house, the thermostat is set at 50C, though after Elver's warning we may have to raise that. The guest room HWS has a tempering valve so it's safe. The reason for two HWS is to avoid the long runs of pipe where the showeree has to stand there wasting water waiting for the hot to come through. The water heater in the guest room, equipped with a tempering valve is located on the other side of the wall of the guest bathroom, in the garage, and is only turned on when there are guests in residence. The main water heater, without the tempering valve, is in the laundry with the kitchen on the other side of the wall and the bathroom on the other side of the laundry, so no long runs of pipe there either.
Of course there is always the chance that the Feds are monitoring this forum and have taken note that I haven't got a tempering valve and there is a squad from the Noncompliant Plumbing Division on it's way as we speak. Keep your head down Hans................oh no.... I've let on the ID of our plumber...
You are safe Boringgeof, I am absolutely certain that you only need a tempering valve when the system has the potential to become lethally hot and that is not the case when you have thermostats governing the heating element. The thing with the solar, particularly vacuum tubes, is that they keep pumping up the heat as long as the sun is shining (only a layer of snow stops them) so they can get very hot indeed. (OK Hans, you can come back up now)