Continuous flow hot water query

Good Morning Murray

It might be worth you also looking at heat pump and solar hot water - the latter can be either electricity or gas boosted.

With ACT and Federal subsidies capital costs can be quite low, and future operating costs will be much lower than either gas or electric - say 25 - 33%.

Start you research with Office of the Renewable Energy Regulator (ORER) - Home Page and then the ACT equivalent.

Cheers

Graeme

Agree with Grahams comments. We went from Electric storage to gas booster solar in February. From Feb until early April we hardly had the boost turned on it Sydney, so the gas charge was minimal.Even now we ware expecting the charges to be significantly lower that the electrical charges going forward.

Common complaints that I have heard when doing my research was under spec-ing the instant heater so it could not supply enough hot water for say two bathrooms and the kitchen at the same time. A good plumber or some research will easily prevent that.

We have Instantaneous Gas hot water here (Rinnai Infinity 26), its bloody awesome.
I wouldn't say its perfect - we added the controller into the bathroom so you could 'set' the temperature (rather than it being a preset 50C), but you do get pretty precise control and just end up having a shower without mixing cold+hot.

Downside of instantaneous is that you really need the unit to be close to where you use the water and that you need a 1" gas pipe wherever that is - which may mean that you have on-costs upgrading the gas if you do not.

We where renovating everything - including all new elec/plumbing/gas so in our case made no difference but i'd imagine if that was not the case there would be at least a few hundred $$ in extras in doing those.

[QUOTE=president_ltd;797472]
Downside of instantaneous is that you really need the unit to be close to where you use the water and that you need a 1" gas pipe wherever that is - which may mean that you have on-costs upgrading the gas if you do not.

Agree that the hot water should be as close to the most oft used tap (usually the kitchen) but any good gasfitter will be able to look up the pipe sizing charts and advise on the correct pipe size. An uneducated plumber will immediately say 1" and try to screw extra money out of you. Southern states should go for a 21 or 26 litre model. Here in Brissy I'm very happy with my Rinnai 16 litre unit.

Originally Posted by murray44

I guess the main reason I asked was that gas is cheaper than volts and I hate the thought of keeping a tank full of water constantly hot, especially in a Canberra winter.

It's gotta be cheaper to heat it only when you need it.

It's very location specific as to which is the cheapest system to operate.

Looking at my own situation, a heat pump worked out the most logical way to go since I have no mains gas available and my limited north-facing roof is already used for solar PV panels and thus not available for a solar HWS. Expensive LPG here in Tassie versus relatively cheap electricity but in other parts of the country it's the other way around.

But as I said, it depends on the situation. If it were me, I'd do the math using your local fuel prices on instant gas versus electric versus solar/electric, solar/gas etc and see how it actually works out.

It's the same with space heating. Some people can get firewood at almost no cost so in that case a wood fire makes sense. Others live in the city and can't realistically use anything other than electricity of mains gas. Other people can't get gas anyway. And of course prices for all fuels do vary a lot between regions.

For example, there's good reason why Victorians tend to favour gas space heating and Tasmanians prefer electricity - cheap and widely available gas in Vic but electricity is expensive versus very limited mains gas availability, high LPG prices but relatively cheap electricity in Tas. Go to Qld and nobody is going to worry too much about heating since even if you have something that is expensive to operate, you won't use it enough for that to really matter.

Also don't forget the local climate with the hot water too. Anywhere that goes below zero you need to make sure that any solar or heat pump system is appropriately designed otherwise it will either break (due to freezing) or at best leave you with insufficient hot water. That said, get the right system and it will work just fine...