Renovations08

Started Building

2011-07-09T17:50:00.007+10:00

In the months since my last post we have:

Run a tender process to select a builder
Choose a preferred builder and work through a series of cost reduction options to keep the project within our budget
Had the builder mobilise on to the site and put up construction fencing
Started work!

Here are a couple of pictures showing where we are up to. The piers have been drilled and filled with concrete, strip footings have been laid and the sub-floor walls have been put up. The builder is now forming up for the slabs which will be both slab-on-ground and suspended.

This first picture is of the strip footings in place.

This picture shows the sub-floor walls now up with plumbing in place also.

First Electric Car in My Suburb!

2011-05-29T22:29:00.002+10:00

Driving home today I saw an unusual looking car not far from home. I recognized the shape as a Mitsubishi iMiev. It looks bigger in real life than it does on the Internet. Anyway, I'm really interested in having a better look and if the car appears regularly i might go to try and meet the owner. I think electric cars are going to take off and will become mainstream far faster than expected. This is the first one I've seen in real life.

Location:Chatswood,Australia

Food Miles

2011-02-22T12:52:00.003+11:00

One concept that comes up in the discussion on sustainability is the carbon footprint of our food supply. The transport of food around the world must consume a large quantity of fossil fuels, particularly when foods are chilled and/or express delivered by air. Our, rather small, attempt at reducing our food miles is shown below. We've cut the food miles for these carrots down to about 8 steps from our front door. They were watered with collected rainwater only and grown with seeds from Diggers. They may be small and mis-shapen but the fact that they are home grown and cultivated with family makes them taste better than any carrots from a bag.

Solar Hot Water in China

2010-12-08T22:46:00.005+11:00

So part of what has been keeping me busy across the last month is a large infrastructure project being partially completed in mainland China. It is an excellent project involving public transport that I'm very happy to be involved with. Anyway, last week I made a trip up to the manufacture site and was reminded of the prevalence of evacuated tube solar hot water heaters in China. Despite it being -10 degrees outside with snow on the ground, solar hot water systems could be seen on most roof tops. I can't be sure that they were still contributing much heat but it has clearly been determined that they are still worthwhile. Now if they are worthwhile at latitudes North of Pyongyang then surely they should be worthwhile in sunny Sydney!
Here is a picture taken from my hotel room showing solar hot water systems on the roof of the adjoining building. Yes - that is snow all over the roof.

Production vs Consumption

2010-12-08T21:31:00.002+11:00

Since our solar panels went in our production has been 300 kwhr and our consumption only 170 kwhr. I'm very happy with the excess but have to keep reminding myself that it is summer time now and that the ratio will probably be reversed during winter time. I better bank a few credits while the sun shines!

Thanks to Jeff for alerting me to http://www.pvoutput.org which is a site that allows PV system owners to compare outputs. Its a handy resource and hopefully the competition between owners results in more people looking after their systems in order to ensure the highest output.

Apologies for the total lack of posts through November. Work commitments stacked up and didn't really leave me with enough free time to progress any of our projects during the month.

Efergy E2 Power Meter - a handy addition for the data hungry

2010-10-31T22:16:00.008+11:00

Our recent PV installation (completed before the hopeless NSW government completely backflipped on their thoughts on Feed in Tariffs on October 27, 2010) can with a little extra. A small electricity meter that clips over the incoming active line and wirelessly sends consumption data to a small readout box you can keep inside. I thought this was a bit of a toy at first, and having been around the house with my Power-mate, figured it wouldn't be too much use. I even tried to negotiate the removal of the meter and a lower price for my solar install but no such luck with the installer. So now I have an Efergy E2 monitoring our electricity consumption. The internal readout display looks like this:

While the external unit simply clamps around the cable and connects to a non-descript little box that you never see because it stays in the meter box. Range seems to be fine in our double brick place though once we extend it may be a problem. No sign of missing data so far. The display shows instantaneous consumption, daily cumulative consumption and an average daily consumption figure. These three parameters are shown in several units - kwhr, kgCO2 and $. As the last two are simply scaled versions of the kwhr I find that I only use that unit but others might differ.
Anyway - I've actually found the unit to be surprisingly useful. Metering appliances one by one is interesting but if you want to control your consumption you need to keep a track of all appliances simultaneously. With the efergy, I can check the device before I go to bed and make sure that nothing is left on, resulting in some real energy savings.
The sensor for the unit is a non contact clip. I believe these units are not particularly good at measuring some types of load and we have found the unit doesn't give the same ready as my trusty Powermate on some devices. That said, its still handy to have around.
The E2 also links up with the elink software to allow the PC based generation of charts and figures. The software is a little clunky but it does work. Here are a couple of the interesting charts you can pull up:

I haven't really explored options for extracting the data into other file formats for other processing. I presume there must be a data file somewhere in there but am too occupied with other projects at the moment to do any proper digging around. Note that while this came with our solar system, it only measures household consumption and does not provide any PV power generation data. I suppose you could buy a second unit and clip it over the PV cable but that data would be available through the inverter logs anyway.
Here's my stab at explaining our power consumption for today.

Honeycomb Blinds

2010-10-28T21:54:00.004+11:00

When we moved in to our house in 2008 it had an assortment of window coverings. Most windows had Venetian blinds, some had lace curtains and others had grandmotherly adornments across the top. We pulled out all the old curtains but left the Venetians in place so that we still had some form of window covering. The Venetian blinds still work fine but don't feel like a particularly thermally efficient window covering. The metal blades would be good conductors of heat and even when fully pulled, significant gaps between the blades and around the perimeter allow significant air movement against the cold (or hot) window.
The standard solution to improve the thermal efficiency of existing windows is to use heavy curtains and pelmets. Unfortunately the layout of our dining room prohibits this because the two south facing windows are located close to the internal walls. There is no room to pull back the curtains and so they would have had to sit in a way that would resulted in a partial permanent blocking of the light coming in the windows. As these windows are already on the southern side of the house and the room a little dim, this was not going to be acceptable.

Our solution has been to install a pair of honeycomb blinds. Honeycomb blinds use a fabric with a hexagonal cross section so that there is a volume of air between the window and the room air. This honeycomb air acts as an insulator to give the blinds good thermal performance. The blinds also compact nicely along the top edge of the window when not in use. We measured the frames and ordered online. Months ago. And now that winter is over, our blinds have finally arrived. The installation process was easy and took less than 10 minutes per blind. I think the results are quite good. The blinds are semi-translucent and let in a little light but fit neatly within the frame. They are also a very simple push/pull adjustment meaning no cords or chains (safety hazards for young children) are required. We won't be able to tell what their winter performance is like until next year but in the mean time, they certainly clean up the aesthetics of the room. The cost wasn't exactly cheap at about $400 including postage but then window coverings all seem to be pretty expensive. Here's a couple of pictures showing the blinds down and from the side.

Photovoltaic Solar Power

2010-10-08T12:26:00.002+11:00

One of the simpler bolt-on upgrades you can do to a house is the addition of a solar photovoltaic array to make your own electricity. We decided to proceed with an installation to take advantage of the very generous NSW Solar Bonus which promises people 60c/kwhr for every kwhr produced. We spent quite a while considering whether to put in panels given the compromised federal rebate scheme currently in place but decided that the benefits of the NSW state FIT tariff were too good to risk missing out on by delaying installation. We also made sure that we had taken the sensible opportunities to improve the energy efficiency of our house to make sure we weren't wasting electricity before taking the relatively expensive step of installing new renewable generating capacity. It would be irrational to spend thousands of dollars to generate renewable energy without first minimising your own consumption to maximise the environmental effectiveness of the installation.
Our system is a 3.6kw Power-One Aurora inverter with 1.7kW of 190W Suntech Mono crystalline panels. The inverter is oversize to accommodate a future expansion of the system when we have more roof space. The array is mounted on a north facing roof with only minor shading early in the morning. The roof is well suited to solar installation and with 30 degree tilt, no additional frames are necessary. I'm hoping for good production figures because of the use of quality components and good orientation. Our installation was done by the Green Solar Group. I sought quotes from multiple suppliers and while Green Solar weren't the cheapest, there were several aspects of their proposal that made them the front runner.
Of order of importance to us these were:
1. Quality components - particularly the Power-One Aurora transformer-less inverter. During this solar boom, installers are putting in all sorts of new/unproven equipment. This might make sense in the short term but cause heartache later on if it is found to be unreliable. I wanted equipment with an established reputation and believe that Power-One and Suntech have such a reputation.
2. Timing of installation - at the time of the installation there was some uncertainty about how much longer the Solar Bonus would continue in its current form. Green Solar promised and installation time that was fast enough for me to be confident that we would have a complete system prior to the Solar Bonus changing. As it happened, they brought forward our install by a couple of weeks when an earlier slot came up. (There was also later advice from the government that mere registration for the scheme rather than registration and installation is all that is required in order to secure the Solar Bonus, reducing the importance of timing).
3. Completeness - Green Solar provided a professional quote with proper estimates of generation, a full description of system components and the inclusion of meter change-over costs.
4. Cost - Green Solar came in at slightly less than the nearest quote for similar equipment but a bit more than the cheapest quote I got. The same sized panel system could be bought for less from other suppliers but my judgement at the time was that such a system would not reach the same standard in terms of quality, timing and may not include all the items I would end up having to pay for.
The installation proceeded smoothly despite a couple of stops to wait for the roof to dry between rain showers. The install team used appropriate safety equipment and harnesses to secure themselves to our relatively steep and slippery tile roof. The work was quite neat and the inverter installation was nicely done with the cables routed through the double brick cavity from the panels and too the fuse box. I can't get a real good look at the panel installation due to the position of the roof and will have to wait until nearmap next passes over my house to see how they look.
Anyway, the system is in and we are now waiting for the changeover to a gross meter before it can begin producing electricity. The panels are very unobtrusive and can only be seen from a few locations on the street. I'd rather not have them too prominent as I know they score mixed (read: negative) reactions from some punters. The panels aren't there to greenwash our house, they are there to demonstrate that a typical residential house can produce its own electricity. Based on the last year's consumption, averaged across the year, the panels will provide 100% of our consumption (though obviously we will have a surplus during the day and draw power from the grid at night).
As a side incentive, Green Solar also include an Efergy energy monitor in their installation. This is a stand alone device (not integrated into the inverter) which monitors the whole-of-house energy consumption. They are available online but throwing one in with the installation does give the customer and additional tool to explore their energy usage at a time when they are likely to be motivated to do so. Its a justified and useful inclusion in their offering and ours is now wirelessly monitoring and recording our consumption for later analysis. I'll throw up some of the charts the software produces when I get enough data to show something interesting.
*Disclaimer - Green Solar do have a referral system which provides incentives for existing customers to refer new customers to the company. If you decide to proceed with a quote from Green Solar and mention Renovations08 as the referrer (hint, hint) I could potentially receive some benefit. I don't believe this potential benefit has swayed my review of their service but you should consider this when reading my comments. :-)

Rainwater update

2010-09-12T18:10:00.003+10:00

The meter is showing 456,067 as at close of outdoor activities this Sunday. Average consumption now sits at 114 L/day. We just got our latest water bill to and our mains water consumption has dropped to 136 L/day for the whole house. Before the tank we were anywhere between 170 and 230 L/day of mains water. Apart from a small leak in the plumbing around the meter the system is working great.

Rainwater consumption results - 8 days of consumption

2010-08-29T21:30:00.003+10:00

I checked the meter today, 8 days after first installing the meter. The meter was originally showing 453,548 just prior to installation. Today, the meter was showing 454, 758 giving a reading of 1,210 L during the period. This is an average of 150 L/day - considerably higher than I was expecting. At that rate, our tanks represent 50 days of consumption. Of course, using the sprinkler on the lawn today probably unduly influenced the result but it will be interesting to see if we end up with dry tanks during a hot summer...

The counting has started

2010-08-22T20:19:00.003+10:00

After a bit of stuffing around with the wrong bits and pieces I got the new meter installed and working today. It fits right next to the pump and the meter section is nice and easy to read. Testing shows no significant pressure drop and the flow rate is still fine. I'll record and publish monthly consumption stats to get a feel for how much water is passing through our system.

How much rainwater am I using?

2010-08-14T12:43:00.005+10:00

Our rainwater system has been performing well since installation earlier in the year and our last water bill showed a good reduction in consumption (though little reduction in the cost!) even though it included a period before the tank was installed. To properly understand how the system is working I want to know exactly how much rainwater we are actually using. Knowing this figure would let me calculate what the cost of water delivered this way is and also work out what the rate of turnover of water in the tanks actually is and jsut generally be an interesting thing to know.
Measuring the tank water usage is a bit of a luxury and I wasn't keen to pay hundreds of dollars for this information so I've been watching ebay for a water meter. There are a few other retail options but the cheapest I could find was still close to $100 so I waited. Last week a proper utility grade meter came up. Obviously these are not highly sought after and by the end of the auction it was mine for $1. It has now arrived and I've just come back from testing it in the backyard. It measures in cubic metres but has three decimal points so actually shows litres as well. Its a nice brass unit and feels nice and heavy. The brand is Elster and it appears to have metered only 453,548 litres. In a typical 3 person house using the target 150L/day/person that equates to an age of about three years. Now I just need to install it somewhere on the pressurized side of the pump and start recording. Here's a picture:

So how much rainwater am I using? I don't know yet but at least I will know soon.

First Flush Improvements

2010-07-19T13:30:00.002+10:00

The first flush system has been a bit of a mixed bag. My previous post here demonstrated the necessity for the device due to the large amount of particulates and other debris coming off the roof. The problem was, the small dripper hole at the base, intended to allow the first flush to drain between rain showers was quickly blocking due to grit. Removing the grit required unscrewing of the base plug which would always be accompanied by a reasonably forceful stream of dirty water, some of which I ended up wearing. It doesn't take long for a routine like that to get annoying so I have implemented an alternative solution.
I have replaced the 1/2 in screw in plug with a brass nipple, a brass gate valve and a barbed adaptor so that I can drain the first flush directly into the stormwater line. A hose will connect the base of the valve to the overflow line meaning that when the first flush is emptied, the water is contained within a hose and cannot splash the operator. I think I'll use clear hose so that I can see the quality of the water being drained. The gate valve can be finely adjusted to vary the drip rate though I expect it too will block like the last plastic plug. All up cost was <$10 with parts sourced from Bunnings. There is further room for improvement here but at least I won't need a change of clothes each time I drain the flush device. See photo for details.

Fully Charged - Electric Car Videos

2010-06-26T10:32:00.006+10:00

Fully Charged is a new electric car series starring Peter Lewellyn. I don't know who Peter Lewellyn is either but apparently he's done green automotive video before and after watching the two episodes produced so far I think he's quite good.
The episode covering the impressive Honda FCX Clarity is a far more rational look at Hydrogen than was done when the same car was reviewed on the BBC's Top Gear where James May gushed and gushed about how the hydrogen car was clearly the future, while forgetting to mention that we haven't really found a sensible way to make the hydrogen that will power all these cars. I'd be more impressed if Honda had designed a car to run on bananas - at least you can grow bananas.
The FCX Clarity vid is embed below:

I've also added a link to the you tube channel to my link lists as I'm so impressed with this series.

Home Extension

2010-06-24T13:32:00.002+10:00

Our house is small. At 110m2 it is well under the average house size despite still having three bedrooms. To accomodate a growing family we would like a larger floor plan so that we can have a little more space and improve the design functionality of our existing house. We contemplated a full knock-down-rebuild but our narrow block, excellent solar opportunity and preference not to raze a perfectly habitable double brick building in preference for a lightly constructed mcmansion tilted us towards extending the current building. We spoke to a number of building designers, architects and others about design approaches before settling on proceeding with one architect. The last couple of months has seen the development of several concept layouts in preparation for a pre-DA meeting with the council. I think we've settled on a good floor plan but there are still lots of details to resolve. The plans currently show the reconfiguring of some internal areas as well as the addition of another 90m2 of new building. At completion we'll still be under 200m2 and should have far better functionality for the kitchen, laundry and living areas. I'd post scans of the sketches now but I haven't yet got permission from the architect so I better get his consent before doing so.

Better draft stopping

2010-06-15T10:57:00.004+10:00

The cold weather in Sydney this last week or two has motivated me to find more ways to keep our house warm. The solid double brick construction is generally pretty sound but you do occasionally feel cool drafts blowing here or there. One source of uncontrolled air movement is the venting that has been built into the upper external walls. Most rooms have at least two vents and it is possible to see daylight through these at certain times of the day. I have previously covered the vents with clear mylar film to reduce the hot air that escapes through the vents but these still leaked a little. Initially I was concerned that the vents must be in there for a purpose and didn't want to permanently seal them. To get advice I started a thread on the Alternative Technology Association web forum. I like this forum because the people on it are generally real enthusiasts with a genuine interest in sustainability. The thread was started months ago but received a follow-up post the other days and that triggered me into action - it was time to seal up the vents for good.

I used premixed cement render and an assortment of tools from the garage. Firstly I roughened the surface of each vent with a scraper and then removed any loose material. Then I just slapped it on and spent a bit of time getting the surface level and flush with the wall. I'll wait a week or so and then put undercoat and topcoat over the former vents and hopefully have a warmer house for the rest of winter. It looks a little ordinary before painting but shouldn't be noticeable once the colour matches the rest of the wall.

Full Tanks!

2010-05-27T13:40:00.003+10:00

Our 7,500 L tanks reached the full state for the first time yesterday. Anyone in Sydney would know it has been pretty wet recently and our tanks have been diligently catching all that rainfall. Once full, the tanks feel rock solid. When you tap on the sides there is no hollow echo any more, instead it feels like solid concrete. The overflow mechanism is getting it's first test and I can see one small leak around the exit point on the tank. The leak is small but I will try to fix it up with the liberal application of more silicon.
Now we need to find more uses for the rainwater. We already use it for toilet flushing, washing clothes and watering the garden/washing the car etc but clearly we aren't using as much as we're collecting as we've filled the tanks in under three months! One option might be to share the water with the neighbours who water their garden more regularly and enthusiasticly than we do - perhaps we could offer to run a hose next door for them to use instead of the mains? Given that they are down hill perhaps it could even be gravity fed so as to avoid pumping costs and wear? I think I'll make the offer and see what response I get.

Here's the Bureau of Met's rainfall chart for the past 24 hrs. I think my house is somewhere in the more north of the two main orange spots.

An approach to electricity consumption

2010-04-12T13:24:00.004+10:00

While looking for power consumption figures the other day I came across the Sokitt website. This site has lots of interesting information on power consumption and also puts forward what I think is a sensible approach to reducing individual power consumption. One of the messages is to spend your time productively by reducing power consumption in the things that will actually make a difference. If a device only uses 1/2 a Watt in standby power it probably isn't worth working too hard to eliminate that consumption. On the other hand, if you have a pool pump running at 800 Watts then this is a demand that should be managed carefully and will likely yield good results. This seems sensible to me. While it might initially be satisfying to cut consumption everywhere, in the longer motivation will come from results and these results will be best if we focus on the things that matter. I thought about trying to categorise things around the house into the two categories and came up with this list:

Things that matter (and deserve your attention first):

Resistive electric heating - large wattages and run for extended periods of time. Replace with a suitable alternative
Resistive electric water heating - water is hard to heat up, particularly when you keep using it to shower
Lighting - halogens (and to a lesser extent incandescents) are more like heaters that happen to make a little light as well. Minimise their use where possible
Large appliances that are on all the time - fridges can range in consumption from 200 kwhrs/year to 1200 kwhrs/year. Buy the smallest, most efficient appliance that will satisfy your needs. Be realistic about your needs!
Standby loads over 10 W. Anything over this amount will add 90 kwhrs/year to your bill ie approximately $20/year at current rates. To me this is probably the limit of relevancy though real enthusiasts will go for a lower figure.

Things that don't matter (or that can wait till all the things that matter have been addressed)

Standby loads under 2 W (think mobile chargers, DVD players, stereo LEDs). Between 2 & 10 is a bit of a grey area that depends on how far you want to take your energy reduction.
Power consumption for items used at low frequency - don't worry if your food blender is 1500 Watts instead of 500 Watts - you will probably only use it for less than 10 minutes in a year.
Adding to your electrical power consumption by substituting internal combustion engines (think lawn mowers and whipper snippers) with electric equivalents. These might add to your electricity bill but they will reduce your fuel bill and probably (depending on electricity sources) reduce your emissions as well. Two stroke devices in particular should be targeted because of their oil-burning nature. (Should this be on the things that matter list?)

Taking a sensible approach will ensure we get maximum reward for our consumption reduction efforts. It would be disheartening to spend time on the things that don't matter and find that after significant effort an insignificant change in power consumption had been achieved. Focus on the things that matter and the results should reward your efforts appropriately.

Why do you need a first flush?

2010-04-09T12:43:00.005+10:00

Our rainwater system has been up and running for a few weeks now. After reasonable rains over Easter our tanks are over half full and we are using the water for toilet flushing and clothes washing. There hasn't been much garden watering going on because of the quantity of recent rain. The pump supplies good pressure to the outlets though we haven't yet had a situation where more than two users are drawing from the system at once. There is plenty of pressure when using a hose with a trigger nozzle.

What I wanted to put up in this post was the result of a quick clean out of our first flush system. I wanted to see how much dirt and leaf matter had been collecting so I drained the first flush after a downpour had filled it. The result was surprising. I collected the first flush water in a tub and was very surprised at the amount of dirt and organic matter in there. The bottom of the tub has lots of dark dirt and muck. Closer inspection shows it to be a mix of moss flakes, decomposing leaves and a bit of dirt/grit. There is far more than I was expecting. Our roof is quite old and has a fair amount of moss growing on it. I also didn't clear out the gutters immediately before starting to collect the water. They were cleaned about a year ago however so I don't think they should have excessive build-up of dirt.

A picture of the first flush flush is below.

I think the lesson here is, definitely install a first flush unless you want this sort of stuff in your rainwater tank.

A reader also pointed out that I hadn't published any pictures of the finished installation. Here are two pics that show the collection and pump-out end of the tanks. As can be seen, the tanks are located down the side of the house and quite unobtrusive. There is still plenty of clearance for access down the side of the house and by putting the slab down there I have reduced the amount of grass I need to mow every couple of weeks!

Accidently saving energy when buying a dishwasher

2010-03-30T13:07:00.001+11:00

Ever since our family grew to include a third person we've been using the dishwasher a couple of times a week. With a baby/toddler in the house time is short and anything that helps free up a few minutes is appreciated. Needless to say, I was a little concerned when our dishwasher started to play up a few weeks ago. Instead of obediently washing the dishes when I hit the appropriate buttons, the dishwasher went on strike and decided to wash at a time convenient to itself. This time did not often line up with our preferences. A few pushes and shoves to the door didn't change the dishwashers mind so we decided to put him out to pasture to think about it. A replacement machine could be sourced for less than the cost of a technician's call out fee so two days later I won a auction for a replacement washer through my favourite procurement channel Ebay. We bought a Bosch machine as Choice reports showed their machines generally had low power consumption and reasonable washing performance. The new machine also matched the dimensions of the cavity left by the old machine.

Saturday was spent cleaning up the mess the old dishwasher left behind as a final protest. A leak at the back had soaked the MDF board underneath the washer which had then swelled up and started to fall apart. By Saturday night the new washer was in and performing a test cycle. For interest's sake I put the power meter on it to see what kind of power consumption I could expect. With the machine on the "eco" cycle it returned a full cycle power consumption of 1.1 kWhrs. This compares to the old washer's consumption of 1.7 kWhrs - a 35% reduction in energy consumption. Assuming that we run the dishwasher every second night this equates to a 6% reduction in our whole of house power consumption! An excellent result and one that comes at very little cost/effort. Here's a pic of the new machine:

Of course there are more efficient models out there and perhaps in the future we'll look to install one of those, but to keep the pile of dishes under control we'll take the ebay Bosch as a good stand in. Here's hoping it lasts long enough to pay itself back!

Simple Mains/Rain Switching

2010-03-24T13:25:00.006+11:00

One of the problems of using rainwater is that unless you have a huge tank and collection area, you are occasionally going to run out of water. If you're relying on that water to flush the toilet then you need a back up supply. The traditional approach has been to top up the tanks with mains water but under the water restrictions that were previously in place this meant that the tank water could no longer be used to water the garden as it's source was no longer just your roof top. To remove the need to top up, pump manufacturers developed automatic switching devices such as the Davey Rainbank, the Grundfos Pump Genie and the Onga Waterswitch. These devices are mounted on the high pressure side of the pump and monitor the tank level to determine which water source to use. When low tank levels are detected they automatically switch over to a mains supply. These are clever devices that reduce the user intervention down to zero but they cost quite a bit (>$500 AUD), constantly consume electricity and can occasionally fail.
For our installation I wanted something simpler, cheaper and more reliable. A manual equivalent so that I could control the source of the water going into the bathroom and laundry without having to unscrew connections and pipes. The plumbing system we have put in allows the internal connections to source mains or rain water depending on the position of two valves. The external taps are rainwater only. The plumber wasn't completely familiar with the requirements in order to do this work so I did a bit of research and found a few diagrams in the NSW Plumbing Code of Practice that we used as a guide. We must have got it right because the plumbing inspection signed off on the combination of valves, non-return valves and dual check valves as being acceptable. The cost of components for this system was under $150 which is a stack cheaper than a switching device and it has no electrical consumption and will be as reliable as regular plumbing components. The pipe coming in from the right is the rainwater supply line, the line from the left is the mains water back up and the internal connections are at the top. The photo shows the necessary ball valves and one way valves to ensure that there is no contamination of Sydney Water's supply.

NSW Labor waste my money ... again

2010-03-22T17:46:00.000+11:00

Quietly, and without any real notice, Sydney Water changed their conditions for the rainwater tank rebate in December 2009. From that time onwards, all rainwater tank installations involving connection to the mains are now required to be visually checked on site by a plumbing inspector. The process is called a "quick check" and was previously only required for sewerage connections and the like. The inspection costs $170 and also requires the presence of your chosen licensed plumber.

Apparently the inspection is intended to ensure that applications for the rebates from dodgy folk who haven't actually installed a tank can be weeded out and no rebate paid. A worthy objective for sure but why didn't the original process work? Firstly - all installations are required to be installed by a licensed plumber who confirms that the work was done and done in accordance with the relevant standards. If a subsequent inspection is now required, why did I need a licensed plumber in the first place? If the work is now going to be checked by a qualified inspector why can't I do the work myself? What is the point of licensing the plumber if their judgement isn't trusted? What does the license actually represent?
In cases where subsequent audit finds that the tanks are not installed or plumbed as signed off by the plumber. Why is no action taken against the plumber or applicant in this case? Why does the honest applicant now have to waste $170 on an inspection that takes all of 5 minutes? Further, why does a five minute inspection cost $170 and how does the requirement for payment for the inspection fit with the concept of a rebate from the same authority? Are we actually trying to encourage people to install rainwater tanks?

What is the dispicable, untrustworthy NSW Labor party going to do next? Will they announce a $500 rebate for the return of old inefficient fridges with a small catch that includes a $495 application fee? How about a solar feed in tariff coupled to a levy to pay for the tariff?

First Rain

2010-03-11T21:05:00.002+11:00

The first collection of real rain in our water tanks!

Plumbing

2010-03-11T13:35:00.001+11:00

We had a few people quote on doing the full supply and installation of water tanks before we decided to buy the bits ourselves and hire a plumber on hourly rates. We took this path because none of the full job quotes we received seemed to procure parts at reasonable prices and they all included over $1000 for labour for the install. I thought we could do better by doing part of the work ourselves (pour slab, buy tanks, buy pump) and then just getting a plumber to do the parts of the work that must be completed by a licensed plumber. After calling around I found a reasonable, licensed plumber who would work for $65/hr + GST and was willing to listen to what I actually wanted done in terms of being able to connect both mains and rain water to a single tap (there are specific requirements on this in NSW).
The plumbing has now been done and all up it took 12 hours of labour to do the following tasks:

Join the three tanks together with blue-line poly pipe and metal ball valves between each tank
Connect the pump to the outlet of the third tank with blue-line poly
Run 14m of PEX type pipe under the house
Install two outdoor garden taps
Install a new tap in the bathroom for rain/mains water
Cut in to the laundry water supply with a rain/mains water line
Install check valves and ball valves to the standard required in NSW for interconnection between rainwater and mainswater lines
Install interconnecting copper pipework between the laundry, bathroom and back garden tap
Test and commission the pump and system

The way the system is configured I can manually switch between mains or tank water by adjusting two valves on the back wall of our house. I chose to use manual valves rather than a rainbank or pump genie system because I had heard reports of these systems failing and/or still using significant quantities of mains water due to start-up issues. Two valves are pretty simple to operate though I don't anticipate needing to switch them often. Check valves and non-return valves are installed to ensure that there can be no backflow between our house and the mains. In addition to the two such valves installed by the plumber, Sydney Water will also install a dual check valve/meter now that we have a rainwater tank. These water guys love system redundancy - there are three levels of backup here!!
Anyway - while we saved money on labour (total $750) and parts (unquantified) we still paid more than I expected for miscellaneous valves and fittings ($570!). If I were to do it again, I'd agree a list of parts required by the plumber and then buy them myself. I'm sure I could cut that miscellaneous fittings cost in half.

I'm still very happy with the result. Our 7500 L system came in at a total of $4150 (before rebates). This figure is 2/3 the price of the cheapest quote we got (for a 4000 L system) and only 1/3 the cost of the most expensive quote (again, for a 4000 L system). I also feel like I have a good understanding of each of the elements of the system and could pretty quickly diagnose a problem which might not be the case if my only involvement was to write a cheque. Now we just need to wait for it to rain so that we can start using real rainwater!

Pumps

2010-03-11T12:50:00.000+11:00

Our tanks sit on the low side of the block so we will need to use a pump to push it back up to the bathroom and laundry. Due to the increasing popularity of domestic rainwater tanks, small pumps are quite common these days. Aldi even had one in their weekly catalogue last week ($99!!). I canvassed a few sources for their opinion on the merits of each brand and got a really mixed bag of responses. Some said stick with known brands, others said there was value in the no-name Chinese made pumps, others just wanted to sell me whatever they had in stock.
In the end I chose to go with a Grundfos CH2-30 PC pump and pressure controller. Grundfos were recommended to me by fellow engineers who work in the water industry. This pump is at the premium end of the range and is priced accordingly but given the criticality of the usage (lacking water to flush the toilet would be considered unnaceptable by SWMBO) it seemed sensible to go with the pump that appeared to have the best chances of holding up under use. We shopped around a bit and found a pretty wide range of prices. Sydney had higher prices than interstate and so we bought from a smaller shop in Ballarat! They had the model we were after on special and took our order over the phone. A few days later the pump arrived with a few extra connectors and hoses. Thanks to Bridgeswade for the pump. (note - their website has changed significantly since I bought the pump and I can't find it on there any more)
Before deciding on this model I did some research into pump sizing and power consumption. I chose the smallest model in the CH range because it seemed like it would provide sufficient flow rate and pressure for most circumstances and deliver lower power consumption than larger pumps in the same range. The Grundfos pump curves show a relatively flat power consumption vs flow rate curve meaning that a large pump operating at low flow will still use the power of a large pump. The CH2-30 PC is rated at less than 500 W when operating so it doesn't have a huge power draw. I'll put the meter on it to check once we get a bit more rain. Most plumbers wanted to install a bigger pump. I don't know if that was because that resulted in more margin or better operational properties but I don't think they were concerned about power consumption like I am so I bought the model I thought would be best. We'll see if that was wise in the next couple of months.