Renovations08

Heat Pump vs Solar - Power Consumption Results 2016/17

2017-09-27T18:30:00.001+10:00

I have recently been posting about my new solar floor hydronic heating arrangement. The short version is that now the system runs solely on solar power and the heat pump that had been providing heat for the system has been removed. The resultant impact on our winter season power consumption is impressive. This chart shows a comparison of our daily power imported from the grid between last year and this year.

As you can see - getting rid of the heat pump (and installing an additional 2.1kW of PV), has resulted in a massive drop in our grid power usage. Last year we had many days between 20-30 kWhrs and some exceeding 30. This year we don't exceed 10 and go as low as 2-3kWhrs some days. I am very please with this result.

Solar Won't be Enough

2017-09-16T17:44:00.000+10:00

My grand plan for a solar hydronic floor was always going to need more than solar to make it work. I didn't have the space for so much solar collector that I could store mountains of heat in a massive storage tank overnight so I was always expecting to have to add some kind of boosting. I can confidently share with you at least three ways not to do boosting.
With solar PV on the roof I figured that I would prefer to use an efficient heat pump to supply the boosted water. I figured that with a pretty efficient building envelope I wouldn't need too much added heat so my first attempt was a regular domestic hot water system. A Stiebel Eltron WK-300 or similar. This is a combined heat pump/storage tank of 300L capacity. It had relatively low power draw at something like 1kW with a typical COP of about 3 giving heating power of about 3kW. The result? Not enough hot water and a heat pump that ran constantly. The floor just seemed to suck up all the heat in the tank which then ran at too low a temperature to heat the floor. No to worry - the Stiebel went back on Ebay and another configuration was developed.

The second configuration was a monster 400L tank on a 2.4kW heat pump. The unit was branded Taitron and I bought it from a man who claimed to be a hydronics installer in Adelaide. The unit arrived and was so big I needed to make another slab for it to sit on. The first disappointment came when I first filled in with water only to find it pouring out of the unit because the unit was incomplete and was missing a circulating pump. Back to ebay for more parts and I finally got the unit going except that it had a bad habit of causing the circuit breaker to pop when starting on cold mornings. A few hours of googling later and had determined that it needed a crank case heater to be added because the compressor was stalling in the cold weather. Ebay to the rescue again and a the crank-case heater was added. A constant 50W draw was not my idea of efficiency but it seemed a small price to pay for a unit that would actually work. Except it didn't. The unit still took a couple of hours to heat up a tank full of water which the floor would chill down in less than 40 minutes. The unit simply couldn't supply enough heat, even with the solar circuit also boosting the tanks. I ran it in this configuration for a season before cracking it with the solar circuit and trying the third configuration which was to ditch the solar (in case it was somehow thermosiphoning heat overnight) and just running on the heat pump alone. This was not a good idea either. Our electricity consumption spiked to peaks of 40kwHrs/day for a marginal heating solution. The heat pump was constantly churning in the background and while the noise wasn't terrible, it sounded so much quieter each time it stopped. What a disappointment. We considered the options and regrouped. Maybe we just had to go for a gas boiler. A few quotes made us look for other options. The lowest quote we got (and remember this is just for the boiler installation - the hydronics and pipework are already installed) was for $8k AUD. That also excluded some elements of the installation like a gas line upgrade which was going to be extra. That price made my eyes water, particularly as our builder's price to install the pipework had already been exorbitant. It also compared badly to a reverse cycle ducted system which could be had for the same money, could deliver similar heat levels and had the bonus of working as AC in summer time.

As a last ditch effort I thought I'd try one last configuration. I pulled out the Taitron and simply connected the collector panels in a single loop around to the floor. A small, partly filled balance tank served to ensure there was always water stored at the low point with the single circulating pump. The water now runs from a single pump, through the panels and then back under the house to the hydronic manifold. The results of this setup were very surprising.

Hydronics Data

2017-09-13T22:15:00.002+10:00

One of the things I initially struggled with on our hydronic set-up was just understanding how the floor system was delivering heat. There are seven floor circuits which are connected up to a single manifold and the hot water is delivered to the manifold in larger pipes from the heat source. Each floor circuit has a separate valve that can be used to adjust the flow rate. There is also a flow meter in each circuit though the readings can be quite hard to take. My problem was that I had no idea whether the warm water was flowing evenly between the circuits other than by just touching the pipes to feel for warm water. I also had no idea whether the water was returning at a constant or variable temperature across the circuits.
My old favourite website (autospeed.com.au - still a great site even though Julian Edgar has moved on to other things) had an article pointing out the multitude of small electronic components that had become available at cheap prices on ebay. These included very cheap ($3), small colour thermometers. The price is so low that you can afford to buy one for each variable that you want to measure so I bought 9 and set about making a monitoring rig. The rig is very basic. It simply comprises of the temperature probe for each thermometer taped and then insulated (to avoid measuring the air temp in the cupboard) and the gauge taped close to each circuit. Power is from a single switch-mode power supply. I also measure the incoming water temp and the combined outgoing line for good measure. Here is a picutre with the temperature monitoring rig turned on:

And here is a picture where you can actually see the return water tempeartures. I generally aim for even temperatures across all circuits figuring that that must represent some kind of balance but really I should probably just measure floor temps and see what feels best under foot.

The Big Plan - Solar Hydronic Heating

2017-09-10T20:22:00.002+10:00

One of the areas I wanted to explore new ideas in our renovated house was heating. Our original house was double brick and quite solid but with small windows and no real passive solar design features it was cold in winter. The thermal mass of the brick certainly helped control temperatures in summer where it would take a hot spell of several days before the house would overheat and cooling was required but in winter time the house never really warmed up.
My preferred solution to this problem was to install floor heating in the new slab and also to retrofit it to the new screed slabs in both renovated bathrooms. Hydronic floor heating has many appealing features including full integration into the building envelope, safe operation, comfort under foot and, according to some people, low operating costs.
My grand plan for floor heating was to use solar heated water to further minimise the costs of heating. Our roof is quite steeply pitched and the terracotta tiles are slippery so I didn't want to spend time on the roof installing the collector panels so I found an alternative. In winter time, the sun projects in at a low angle from the North (I am in the Southern Hemisphere), as opposed to in summer when it blazes directly overhead. The angle is so steep that a collector mounted vertically can collect a substantial amount of light across the winter months. This opened up the possibility of mounting the panels on the north facing wall on my house which, as you can see from previous posts, is bathed in sunshine through winter.

Relatively cheap evacuated tube collectors flooded the Australian market some time around 2012. I bought three from an importer and then spent a weekend bolting them to the wall with a home made bracket system that meant I didn't have to use the whole frame. This was a big advantage as the collector panels only just fit between the top of my rainwater tanks and the brick "eaves" of the building so cutting out the thickness of the frame made the whole panel fit a little better. The sections of wall did not perfectly match the width of the panels so where there are windows, I simply didn't install the evacuated tubes. This cost me some heat collection power but there wasn't really any other option. The pictures below show the evacuated tube array on the side of the house in late afternoon sun. Shadows are starting to creep up onto the array but it still produces useful heat with this level of sun exposure.

I also painted the top manifold cover the same colour as our house to reduce the visual impact of the installation. While this is visible from the street, the uniform nature of the tubes means that the house doesn't look too strange. It is probably less visually intrusive than the solar hot water we have on the roof which sits off the roof on a tilt frame.

So how much rainwater have we actually used in 7 years?

2017-09-07T20:46:00.002+10:00

My last post on rainwater consumption dated from 2010. Back in August of that year I installed a utility grade water meter on the outlet of our rainwater pump in order to start to understand how much rainwater we were using. We have had approximately 6900 L rainwater tanks since 2010 when they were installed during Sydney's last major draught. For a while I recorded meter readings at semi regular intervals on a spreadsheet but then lost the file and generally got distracted by other things. All the while, the meter has continued to tick over. We use the rainwater primarily for flushing toilets, outdoor taps and for a while we also used it in our washing machine.

The original meter reading was 453,541. I checked the meter today and the reading was 600,618. This gives a total of 147,077L of rainwater used, or 21 completely full to completely empty cycles of the tanks.

The time period elapsed has been close enough to 7 years or 2555 days. This gives a result of 57.5L of rainwater used per day. I am actually surprised by that figure. Its higher than I would have guessed. Our usual water bill shows mains water consumption at about 150-180L/day so rainwater is providing approximately 1/4 of our total water usage.

Financial payback is not the goal of this system and in reality is never likely to occur though it is worth noting that at $2/kL our rainwater tanks have "saved" us approximately $300 in direct water costs but then also probably more than that due to reduced sewerage charges being levied given our low water consumption.

For what its worth, the system has been pretty much trouble free over the full 7 years. We have had no problem with the excellent Grundfos CH pump. The tanks are fine. I have upgraded the mesh screening on the first flush in an attempt to stop it filling with quite as much gunk but overall the system has been excellent.

Solar upgrades - More Watts

2017-08-21T21:41:00.001+10:00

In NSW Australia, the very generous feed in tariff (60c/kwHr) finished in December of 2016. That meant an update to our electricity arrangements. For as long as the feed in tariff was in place we were not permitted to adjust our system without also dropping out of the scheme. This meant that we kept our original tiny 1.7kW system even though we had oodles of north facing roof. The end of the scheme meant it was time to upgrade. We decided to add panels to our existing inverter. We had always intended to have a bigger array and so had oversized the inverter from day with only 1.7kW of panels on a 3.6kW inverter. We added another 2.1kW of panels to give a total of 3.8kW. This arrangement now regularly puts out 3kW which gives a bit of headroom over a standard 10 Amp device. We also changed our metering arrangements over to net metering so that rather than sell all our electricity at 6c/kWhr we could get benefit by using it locally first. Given that consumer rates for electricity are now at around 30c/kWhr it feels much better to use a locally produced W/hr than buy them from the grid. Sorry - no photos of the solar - you all know what it looks like anyway.

6 years!

2017-08-21T21:32:00.002+10:00

Renovating a house is often challenging but to tell you the truth I had no idea just how hard it would be. I won't go into the detail but the process was difficult, unpleasant and ended up needing NSW Fair Trading to step in to help resolve an extensive list of disputed items with the builder. Not fun. That all put the brakes on blogging hence the 6 year hiatus on posting.

To cut a long story short, at the end of the build we moved back in and tried to forget the unpleasantness of the build process. We have been living in the house ever since. It is now a comfortable and much bigger family home which is lucky because we are also now a bigger family.

Some of our energy efficiency ideas worked and some didn't and I'm planning on putting up a few posts over the next few months showing examples of both. Either that or I go on another 6 year break!

Busy

2017-08-21T21:22:00.000+10:00

Bloggers claiming to be too busy to post are lame but sometimes its true. Our renovation/extension has been going at full tilt and the arrival of our second child means that there is virtually no free time left. The build has been going well. In late July the slab was poured. and that was quickly followed by the bricklayers putting up the double brick walls around the perimeter. Windows were delivered to site and then installed as the walls were going up. The stand out part of that lot are the multi-fold doors. We have two of these at right angles to one another. Each has five panes and is made out of a beautiful hard wood. They cost enough to keep me in debt for a few years longer but it will be worth it.
The roof went on two weeks ago, but not before the builder installed air-cell sarking underneath the tiles. We were very lucky with the weather through that period as the rain held off long enough for us to make the place water tight before the rain really started bucketing down.
On the sustainability front the solar hot water panel is on the roof (sans tubes for now). The hydronic heating system is cast into the floor and ready for a heat supply and the builder scratched his head for a while and then came up with a way to insulate the perimeter of the slab. Here is a picture of the hydronic pipework the day before the slab was poured. The framed area is the laundry where the slab was kept a little lower in order to be able to put a screed bed in to get the floor to drain to the floor waste.

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.