I changed from a gas continuous (?) hot water system to a gas instantaneous hot water system for a cost of $1200. Massive reduction in gas cost! Only downside is the 10-15 sec delay for the hot water to arrive.
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Ditch the gas, but if you do keep it for hot water, install an instant unit. Much more efficient than storage. if you go solar/electric boosted take the highest volume storage tank you can install. You won’t regret it. Heat pump hot water is very good now too.
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We have just replace our ‘off peak’ electric water heater with a ‘HEAT PUMP’ hot water system.
Our previous bill for the period 11 May 19 to 9 August 19 was $310.31. Our latest bill from Origin for the period 10 August 19 to 8 November 19 was $165.17 (the heat pump was installed on the 22 August and connected to the off peak on the 3rd September).
I am VERY pleased with the results.
Heat pumps are very versatile, they give you access to how you want to use them to get the advantage of using your solar energy, off peak, combination of both, switch them off when you go away on holidays, and turn back on for your return. They are a bit more expensive to buy but your savings are amazing. Hope this helps,
Martin.
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I’ve finally decided that I wont be getting a heat pump system. My average gas use is around $500 a year for cooking and hot water (thats after the rebate I get because… pensioner) but my electricity use is well over that, at around $1400 p/a. That is likely to increase when my new front load washing machine arrives tomorrow. Also, I don’t stint on a/c in summer which seems to be the bulk of it all, because “summer” is getting longer and longer. I’m looking at dispensing with the window rattlers and getting a split, finally, but wont have the funds til we are well into summer. Still… working on it. And a split is a heat pump, right?
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The electricity usage of a FL may very well surprise you. When we moved from a TL to FL (many years ago) we noticed a significant drop in both water and Leccy usage. As we have been using a FL for years now we can no longer make that comparison. FLs tend to use less electricity than TLs do, maybe to do with all the water a TL has to move during a wash. As your clothes hopefully are never too dirty, you can use the short wash cycles to also cut the time compared to a normal FL full wash cycle and reduce Elec usage further.
Splits are mostly now inverters so they are often cheaper to run than old style ACs, though the cost of buying new units to replace your window box ones may not offer good economy as the pay back time could be extended over what elec usage a new one may save over retaining the “rattlers”. If upsizing is required because currently under capacity then that does make more sense to replace them. If looking at heating at any time during the year make sure to get a reverse cycle not cooling only unit. There is a price difference but it isn’t substantial and is worth the extra.
Don’t forget you may also be able to take advantage of an Advance Payment through Centrelink (or Vet Affairs if they are your pension source) to let you get at least one new unit faster than waiting well into summer. It will mean a fortnightly reduction over the next 6 months to pay off the advance (usually a reduction of about $50 - $60 a fnt but no interest paid).
You may also be able to sell the “rattlers” to recover some of your costs eg if you can advertise locally you may be able to get $50 - $100 each for your old units. This will help offset some of the new units costs.
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The problem with the window rattler is its growing black mould (although that seems to have stopped). I’d prefer it not to be here. Yeah I realise that Centrelink offers advances, but I have my fortnightly budget on a tight rein and it would be a PITA to have to change it. OTOH as you rightly say, perhaps I could get a split a little sooner. I only need one, and probably 5-6Kw will be enough, the window rattler is 4.2 and enough even on really hot days, it takes the edge off. Bedroom is well served by a little Close Comfort.
The other thing is I plan to raise another Tuckeroo tree to shade the back of the house. I dont know why the builders thought it was a good idea to have a huge concrete slab on the western side, with no protection from the sun. I think I probably need to get some potted palms for there, alas I cant really plant anything because the other thing the builders did was put the garage, driveway and that slab, over the top of a big sewer line. Otherwise I’d put something in the ground.
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The mould issue is normally that the tray is not tipped far enough back to let the water drain fully from the tray. This can either be fixed by getting a AC stand built that allows the tray to dip further at the back or getting the front slightly more raised by inserting a dowel or similar between the window and the AC (if fitted in a window). If fitted through a wall getting the back end/outside hole dropped a little further down and filling the gap at the top with some gap sealer, expanding foam or a bit of trim fitted over the gap. You could also try having the drain hole slightly enlarged to allow more free drainage.
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Thanks for that suggestion!!
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If you have gutters on the western side another suggestion in place of planting etc is to get yourself some 90% shadecloth (75% or greater will work just 90% cuts much more) that is long enough to cover that wall. Hang the cloth from the gutter with some S hooks (they look like Ss) normally they come with a larger loop one end smaller the other. Poke the hooks through with enough spacing so not using too many but enough to stop drooping of the cloth, you could also fit grommets to the cloth instead of pushing the hooks through. Hang the cloth and you should notice a big difference. That’s the cheap way with the shadecloth, but if you know a handyman or carpenter you can get them to build you a frame to attach the shadecloth to. Top end fits under the gutter or roof edge, the bottom is cut at an angle to slope the shadecloth away from the house. You can get the bottom poles attached to the concrete by either bolts or by fitting blocks to stop the legs sliding out. Because you have created an air gap between the shadecloth and the house wall the heat does not get to build up on your wall. I have drawn a rough example of what I mean, you can add extra legs in the centre part so that the cloth and bearers are well supported if the wall to be shaded is very long.
Get a longer drop shadecloth that allows most of the wall to be shaded. Bottom leg length can be somewhat longer than my drawing shows perhaps up to 60 cm or so before where the bottom bearer is attached. When we made ours at a previous house we also had the top of the legs screwed to the wall and had cords attached so as to stop the shade moving in strong winds. We double layered the shadecloth to maximise the privacy and sun blocking effect. Treated pine was used to inhibit rot and termites as the bottom legs were in the garden soil.
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I think planting will be nicer. I really would like a pergola over the bare concrete and perhaps a grapevine. Ive got some tuckeroo seeds ready for potting up until they grow to a reasonable size and have learned from my last attempt to raise them, not to have them out the back of the house (west) because they will thrive out the front. Once at a reasonable height, they can go out back and will be fine, even in hot sun. And of course now, with my heat pump clothes dryer, they can be watered by hand from the condensed watr from the machine, or grey water from the wash.
Your design will do nicely for the northern side of the house where I have huge windows protected by nothing. Not sure what local council rules are, but I would like to attach the bottom part to the top of the fence (its the side of the house with a walkway rather than a yard as such). Might work.
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A seemingly brilliant and low cost treatment, but would that be a good option in a very windy location? One could ‘lose’ the shade cloth, the gutter, or possibly a facia board - the weakest link could go in a high wind with the shade cloth becoming a sail/kite, could it not?
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It was a popular solution with many of our neighbours in the hot north of Queensland. The upper end of the framing was permanently attached to the underside of the eves at the roof trusses, or the barge boards on older houses. There is an assumption the fence is sound and the neighbour is ok with the added purpose. Every council is different, so no comment behind the obvious that regional shires are a little more understanding, mostly.
We always chose plants over architecture, given time. Smaller understory palms and crushed rock mulch. Grape vines would have been great, if the soil and climate were suitable. Passion fruit or choko vines were favourites with our gran and sisters.
Way off the starting point of the topic.
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On very windy days it is easy to remove it before it decides to remove itself. Generally the cloth or hooks just come off. Never lost a gutter etc to it. Once the cloth gets loose it is heavy enough to fall to the ground with no travel involved. We prefer the fitted solution though as it can be made very sturdy by the use of some rope and pegs or fittings to secure it. As it is not considered permanent it doesn’t get Council disapproval.
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I see where I took this way off topic… could it be split off to somewhere else? Theres subtopics even in the stuff we have been discussing but not sure where they all belong.
My apologies for my drift.
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I’m happy to see the drift. It’s all connected. 
P.s.
Drifting is also an Internationally recognised sport. However its environmental aspirations are opposite to those of reducing household energy consumption through smarter purchasing, or improved insulation and shading.
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And perhaps a few hundred more by heating the water with a solar powered heat pump!
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No guarantee when local winter cloud cover is part of the equation. When one flies to MEL one sees the clouds well before the metro area. That cloud is over my house more often than not. Installation costs not included to replace a boiler with good life remaining.
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Worth looking into when the boiler is near the end of its life though, HPs are hugely more efficient and less expensive to run than gas flames, even on power from the grid.
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If it were only so simple. In the middle of winter the heat pump would save me about $150~200 per month over 3 months, and $10~50 per months over 9 months. Roughly $1,000 pa best case, more likely somewhat less.
A new gas fired boiler a bit more efficient than the current one, $6,000 all up. An ‘upgrade’ to a heat pump was superficially quoted at $15-20,000 requiring all new radiators and additional electrical conduits. My solar system is more than enough to add a heat pump on a sunny day,but rare here mid-winter when you need it to max out not considering pre-sunup and post-sundown power is all from the grid. Batteries? Still a wild card and $$$$.
Bottom line is a 10-20 year payback is not interesting at my age.
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Agree, it’s not.
Gas or wood chip heaters deliver the majority of their energy as heat energy to the hydronic system and therefore warming the house. It’s efficient direct use of the heat energy.
Grid power which is predominantly from coal and gas does not efficiently deliver the equivalent heat energy to a home. The inefficiencies in generation and losses in distribution are only just recovered by the gains at the homeowners end through the high efficiency of typical Heat Pumps.
The way the NEG is currently configured, gas or wood fired heating is a benefit to the grid. Gas heating does not load the grid especially at evening peak. Heat pump conversions can only add to the NEG peak load increasing overall demand.
The ability to load shift a grid powered HP system is limited. There are options for those able to make additional expenditure/investment in storage (thermal or electrical energy). But TOU tariffs seem not to fully reflect the benefit.
Note:
Based on our SE Qld observations more energy storage would not provide a positive household cashflow return. (5kW solar PV, Reverse cycle aircons, wood heating with hydronics, gas HW and cooking.)
We can’t assume there is sufficient sunshine in winter to provide the power or offset the grid imports. Even in our great location on 15 out of 92 days in the winter just ended PV export was less than grid imports. Typically the coldest days of each week. The cost of the backup a shrinking ironbark woodpile is somewhat offset by the savings in gym fees.
It’s compromise. It’s hard to justify further investment when what we have works, and secondly, any new expenditure needs to provide a net benefit in years not decades, given the age we are now.
Given the choice in our household, hydronic heating provides a better environment compared to RC Air.
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