Towards Energy Neutral? A guide to DIY energy efficiency.

TOWARDS ENERGY NEUTRAL?

Well the jury is still out but after 8 years of living Off the Grid, I think we're getting close! After a concerted effort to retrofit an inefficient 1930's weatherboard house into a super energy efficient, minimal impact dwelling with zero heating and cooling costs, there is still more to do but the progress so far is worth sharing.

A brief history....

In 2007 we rescued and relocated a weatherboard house from Box Hill that was due to be demolished. The original dwelling had a minimal amount of additions to deal with the Australian climate conditions: ceiling insulation and some external blinds on the west wall but that was pretty much the extent of it.

We had the house trucked up to the property in Heathcote (about 120 kms from Box Hill) and basically plonked on the designated site. The original plan was to have the solar PV array on the house roof so the house was positioned with the front facing East to allow maximum solar gain on the North facing roof throughout the day. This aspect also avoids any direct sun into the bedrooms at the front of the house (except during Sunrise in high summer...which is quite nice to watch while lying in bed!)

As the house was basically cut in half, transported and "reconnected" on site, the house was very drafty in winter and a sauna in summer due to the gaps in the floors and the absence of any roof eaves. Those who visited in the depths of Winter in the early days will well remember shivering in the front of the fire with the wind howling through all the gaps!

The plan was always to make the house as energy neutral as possible aiming to keep the internal temperature at a comfortable 18-22 degrees all year round. Living 'Off the Grid' means energy efficiency is critical. We do not have the luxury of being able to switch on an electric radiator whenever a chill is felt or running a split system heating/AC unit in the middle of a cloudy spell in Winter so a lot of thought went in to making the house 'immune' to fluctuations in outside temperature.

The work begins....

How to achieve an energy neutral house? I'm no expert but there are several key areas that need to be considered and can be divided into 7 main categories.

1. Insulation (walls, ceiling, underfloor)
2. Shading (external windows)
3. Roof air extraction (including eave vents)
4. Draft proofing
5. Internal drapes and pelmets
6. Cross ventilation (for rapid cool down in summer)
7. Smart cooking and heating


1. INSULATION

This is the most obvious thing! Generally when old houses were originally constructed, little thought was given to insulation. At that time, insulation technology was minimal or non existent, energy was cheap and people just dealt with the extremes in the climate. Walls (and floors and ceilings) were never insulated which explains why there was often a fireplace in every room!

Retro-fitting an old house with decent insulation is not for the faint hearted but its possible! Insulating a roof space is a fairly simple (but messy) job but when it comes to walls and underfloor, now that's a different kettle of fish! Fortunately in our case, when the house was relocated, it was jacked up above the (new concrete) stumps for a week or so. This made it (slightly) easier to get under the house and fix the insulation sheets to the bearers. We used FoilBoard panels that are readily available in Australia through their Melbourne supplier. The panels come in various sizes and are easily cut to size with a knife and simply nailed to the bearers using the special fasteners.

Wall insulating can be problematic and difficult. A weatherboard house has the advantage of having a fairly low thermal mass. This can be a positive or a negative depending on how you look at it. A low thermal mass means that the nature of a timber skin and thin plaster/gyprock walls means that the house will "breathe" easily. This can be a good thing when the sun goes down after a hot day but it also means that (without adequate insulation), it will heat up quickly in the summer and become an ice box in the winter.

Due to the poor condition of the external paint work on our rescue house, we decided to remove every weatherboard wall by wall, insulate with Earthwool R2.0 wall batts and Ametalin SilverWrap. The hardwood weatherboards were replaced by (mostly) recycled Baltic pine boards sourced from various salvage yards in Heathcote and Melbourne.

These insulation improvements alone have seen a massive reduction in the amount of firewood burned during the winter which translates to less chainsawing, collecting, splitting, stacking etc.

Reclaimed shutters. Thanks Paul Champion!

      

2. SHADING

Keeping the sun off external windows is crucial to maintaining a comfortable internal temperature. If you've ever sat in your car for even a few minutes in the full sun, you will know how quickly the internal temperature rises. Remember as a kid starting fires with a magnifying glass? Windows that have any exposure to the sun need to have a mechanism to stop the suns rays hitting the glass. Of course in winter, the suns rays through a north facing window can help maintain a comfortable internal temperature but a west facing window in full sun in high summer needs to be avoided at all costs. Internal curtains are good for shading the sun but if the sun's rays are hitting the glass then there is a problem.

Along with external blinds/shutters on all East, North and West facing windows, we also made some shade cloth blinds to protect the west facing walls and windows from the harsh summer sun. The important thing to remember is to make sure the house is completely closed up (windows, shades and shutters closed, blinds drawn etc) if extreme hot weather is predicted.

3. ROOF EXTRACTION

With a well insulated ceiling and roof sarking foil under the roof sheeting, temperatures in the roof cavity can reach 50+ degrees on a hot day. This build up of heat will begin to force its way downward through the ceiling, eventually heating up the rooms below. In tackling this problem, I decided to install a powered roof extraction fan (Edmonds Airomatic) in the apex of the roof. This fan has a built in thermostat that switches the fan on when the roof space temperature reaches 30 degrees. The fan is capable of removing up to 647m3 of hot air per hour on full speed while using only 37 watts! At around $230 it's not cheap but super efficient. For optimum performance, it's recommended to install several vents in the roof eaves to allow cool outside air to be drawn into the roof cavity to replace the extracted hot air. I installed six 30cmx30cm vents in the east, south and west eaves.

Airomatic roof extraction fan.

4. DRAFT PROOFING

This is one overlooked area when it comes to energy efficiency, especially in the colder months. Leaky windows and gaps under doors allow cold air to enter rooms which undermines efforts to maintain a constant temperature. Make sure all windows and doors have adequate seals and close any external windows during the day to keep the cold air out in winter and the hot air out in summer. Wooden floors are also a culprit for drafts so underfloor insulation can also help avoid this problem.

5. INTERNAL DRAPES AND PELMETS

Block out drapes and pelmets on internal windows help not only keeping heat in but also providing an insulating layer of air between the glass and the drape or blind. Exposed windows can lose as much as 40% of a rooms heat during winter and in summer can multiply the intensity of the heat by the same amount. There has been a lot of debate about the merits of pelmets but the general consensus is that they are effective. Warm room air is drawn up from floor level behind the drapes and is trapped under the helmet, forming an insulating layer of air between the window and the curtains/drapes.

6. CROSS VENTILATION

One internal modification that we did to the house was to remove a small internal wall that was hindering the North- South flow of air through the house. After a hot day when the cooling breeze starts to come through, its essential to be able to open doors and windows on all sides of the house to allow this breeze to "flush out" accumulated heat and refresh the internal air. Needless to say, adequate fly screens are essential.

7. SMART COOKING AND HEATING

An often overlooked factor in maintaining a comfortable internal temperature is the use of cooking appliances such as ovens and to an extent stoves. Choosing appropriate meals that do not require lighting the oven in summer will assist in keeping the house cool in summer. Conversely, a slow cooking roast or casserole in winter may help keep the house warm. We use a slow combustion wood burning heater to heat the house in winter using salvaged wood from fallen trees in the nearby forest. This heater can also double as a stove to slow cook dishes during winter. Great for curries and casseroles!

CONCLUSION

After two fairly extreme summers and cold winters, we're now getting a picture of the impact all these improvements have made to the 'liveability' of house. There is generally an 10 to 12 deg difference between inside and outside temperatures in winter and summer with the temperature hovering around a comfortable 18-20 degrees most of the year. As can be seen from the photo below, Jan 17th this year was an absolute scorcher with an outside maximum of 42 deg at around 5pm. Notice that the inside temperature remained at 29 deg which is not super comfortable but a lot better than 41.8 deg!

One thing I should mention is that we managed to source from Ebay, a very efficient split system AC unit that only consumes around 480 watts when set at 23 deg with a medium fan speed. In good sun conditions, the solar array will generate more than twice that amount of power and allows us to run the unit on days of extreme weather completely free of charge and with the battery bank still fully charged!

The trusty ALDI indoor/outdoor thermometer.

Summer Update 2016 /17

Summer Update 2016 /17

Welcome to yet another belated update from Three Dams.

After a pretty mild lead up to Summer with a Spring that really didn’t happen, we now find ourselves in late December enduring torrential rain and high humidity! Finally weather warm enough to use the pool though! As usual, there has been plenty of action here with lots going on in the garden and around the house. The BIG news this year is that we now now have a fence fully enclosing the vineyard! After last years near total destruction of the newly planted Tempranillo vines by kangaroos, wallabies and various other native wildlife, the vineyard is now protected and as I write, all the vines are doing really well and most are now well and truly up and secured on the cordon wire. Things are looking good for a small quantity of wine in 2018.

JAN UPDATE: Shoot thinning completed and 60% vine gro guards removed this week.

In other encouraging news from the Off Grid set-up, the new 880Ah battery bank that was installed in Feb this year proved reliable right through the dark winter months with no power outages or generator use required. In September, I relocated a 295 watt solar panel I had installed on the Melbourne house up to the property which increased the solar array to just over 1Kw (1075 watts). This has given us a huge boost in charging capacity and has allowed the battery bank to recharge much faster during times of intermittent sun periods, common throughout Winter. The enlarged array can also now power our recently installed, super efficient split system AC. A comfortable 25 degrees inside is possible using only 450 watts of power!

In the garden, things have been stepped up too. Cherry and orange trees were added to the orchard along with a climbing blackberry. Wends has planted an abundance of various vegetables including eggplant, corn, zucchini, capsicum, tomatoes and is very excited about the amount of apples this year and the very first passionfruits after about 5 years! Apart from all that, there’s still a lot of time spent in the kitchen keeping us and the visitors sustained, along with plenty of local Heathcote wine to keep everyone hydrated!

Time out at the Heathcote Wine Hub.

The (overdue) Winter update!

It's been a while since the last blog post and so much has happened since April! We're in the middle of the wettest winter we've experienced here at Three Dams and the first time that all the dams are overflowing in July! We've also experienced some pretty extreme temperatures over the last few months and gone through a decent amount of firewood! There has also been a few glorious sunny days but unfortunately not enough to fully recharge the new battery bank we installed a few months ago. The new battery bank has actually provided all the power we require this winter and we haven't needed to use the generator at all so far but the size of the bank requires a larger solar array so the decision has been made to upgrade the PV array. 

Back in 2008 when we set up the initial off grid system, one 120 watt solar panel cost nearly $900. In 2016, I can get 6 x 250 watt panels for a bit over $1100 so over the next few weeks I'll be replacing the under performing 780 watt array with a brand new 1.5kw array.

The depths of winter bring a new task this year...grape vine pruning! Due to the dry summer conditions last year and the subsequent problems with roo and wallaby damage to the newly planted Tempranillo vines, they will need to be pruned back harder than we would have liked. This will be done over the next few weeks and a roo protection fence will be constructed.

All in all, as usual plenty to do at Three Dams.

Autumn is here. April 2016

Well here we are again in another Autumn at Three Dams. As you can see above that we've been enjoying some lovely sunsets as the shorter, mild days and cool nights are starting to come. The summer as usual had its moments with some insanely hot (43 deg) days and blustering northerly winds that put everyone on high bushfire alert. It's the kind of weather where you spend a lot of time peering into the horizon over the trees hoping not to see a telltale plume of smoke! Thankfully we got through ok and are now settling in for log fires and hearty slow cooked meals with plenty of red wine again!

The vineyard also managed to withstand the weather but didn't fare so well with the wildlife! All the vines bar one are alive and healthy despite most of the new growth being devoured by the kangaroos and wallabies. This is apparently no big deal in the first year but our priority before next spring is to erected a high fence right around the vineyard. 

In other news, our new battery bank is installed and functioning well. We now have a capacity of 880 Ah with is more than 4 times what we had before and will hopefully allow us a few days autonomy in the event of cloudy skies. 

The extra power we have now enables us to also run our new (second hand) split system AC unit during extreme weather days. The house is becoming more comfortable everyday and Wends is very happy with the new lounge room layout complete with new (EBay $20) rug! Now you can watch the fire and the TV at the same time!

 

The garden has produced the usual abundance of nectarines, cherry tomatoes and also lots of apples as well this year. The new system of pumping dam water up to a holding tank to use for garden watering has been a great success and has meant we haven't had to buy in any water this year so far. Some heavy Jan and Feb showers also helped fill the tanks. 

So for now, it's back to enjoying the Autumn days and moving to inside jobs as we move towards winter in Heathcote again. 

Ziggy of course will get any rays of sun whenever he can!

Happy New Year! Summer update 2016

As usual, it has been a busy time at Three Dams over the last few months. The good news is that all but one of the 311 vines we planted back in early October have survived the summer so far but the local are wreaking havoc! Due to the lack of Spring and Summer rain, the only food available for the kangaroos and wallabies has been our vines so for a brief period around Christmas we had what looked like a real vineyard with lots of growth trailing along the cordon wire. Alas after an invasion by a mob of Roos one night, the whole vineyard was decimated and all the shoots eaten back to the top of the vine guard! The experts here in Heathcote have reassured us that this is not a big problem in the first year so long as the vines get their roots down deep and get established. 

The other problem with the lack of rainfall is the ability to keep the water up to the vineyard and all the veggies and fruit trees so we've set up a separate watering system using dam water pumped up into a 10,000 litre holding tank. With a bit of help from Google and some bits from the hardware, I've managed to set up an automated watering system, entirely solar powered that waters everything at pre determined intervals. 

In other news, right on cue, the nectarines are back! Smaller than last year (also due to the lack of rain) but sweeter than ever! We also had plenty of apricots, plums and a few peaches with the apples and figs still a few weeks away. All in all, the weather has been a challenge but in the last few days we've had about 45mm of rain with 42mm of that coming in about 2 hrs on Wednesday in a massive stormy downpour.

The energy efficiency of the house is ever improving. We recently made up some roll-up shade cloth blinds to protect the western side of the house from the afternoon sun. We even sourced a very efficient split system AC unit from EBay that we can run off the solar panels in the event of extreme weather. By closing up the house in the early morning, it remains a good 8-10 degrees cooler inside than out mainly due to the wall, floor and ceiling insulation and remote roof extraction fan..

But if you're feeling too hot, there's always our new pool for a cooling dip!

Summer is here again!

Summer is officially here and things are in full swing at Three Dams. 

We're very excited to report that all 311 Tempranillo vines that we planted back at the beginning of October have taken and have already emerged from the grow tubes. After a bit of trouble with the marauding wallabies, the vines have managed to attach themselves to the cordon wire and are well on the way. Of course, the lack of rain this time of the year has proved a challenge but we have utilised our dam water this year and yesterday pumped 10,000 litres into a holding tank to keep the vines happy.

The other great news is the new pool! A few weekends work and 7500 litres of water and its up and running just in time for the hot weather. 

As for technical upgrades, the new combined inverter/charge controller is installed and working well and the upgrade to a 24v battery bank is proving a lot more stable and reliable. Everything can also now be monitored with the laptop.

Exciting Times!

So here we are again in another Heathcote Spring with everything looking green despite the lack of rain this year. Fresh back from the European sojourn culminating in 3 weeks travelling through Central and Northern Spain visiting some of the major wine regions, we're pretty excited to finally get the vines planted. After 8 yrs working on the house, veggie garden, solar system etc, we have finally got the vineyard site ready for planting with the trellising and the irrigation lines done in the last few weeks. Our 300 grafted Tempranillo vines will be shipped from the cool room in South Australia at the end of September, ready for planting. 

Many months of hard work ahead but looking forward to the first vintage in 2018.