Time to look back over the last few months.
Now the cooler weather is here, it’s time to look back over the last 6 and a bit months of activity and see where our efforts at making the house and our lifestyle more comfortable and “sustainable’.
We have been blessed with many gifts, contacts, small loans and untiring friends, so much so that we have been able to achieve far more of our goals since October 2015 than planned. It’s great to get support from people who have been able to share resources with us.
I’ll write 3 posts on the changes, and a fourth on our plans for the remainder of 2016. The three posts will be on Energy, Gardening, Water. These are all interlinked, but it will be easier to cover major features if I break it all down a little.
All of these changes and additions have been done ad hoc, as health, sales and finances permitted. Changes such as the LED lights, blinds and garden were made gradually, over several months as opportunities arose. We haven’t kept a diary of expenses, its more important to keep moving ahead toward the final goal. That being said, we have learned to be flexible enough to shift the goalposts as we have learned more about energy efficiency. The important thing is that all of the goals are achievable.
Here’s the first post, our change to energy use. Most of the changes are to do with cooling, as they have been made over summer. At the end of winter, I’ll do a similar review of our changes to improve the heating of the house.
Part 1: Energy Use-
Thermal mass –
On of the first things we needed to do to bring the house up to a more livable standard was to concrete the floor of the carport (now the storage area), to pave the back garden area and to lay gravel in the driveway and front path.These changes also had a big effect on the thermal mass of the house.
The block had always been muddy or dusty, depending on the season, and in heavy rain became waterlogged. The carport floor was dirt, and the carport itself was unuseable for storage because of dust and condensation, as well as leaking a gutter.
We had the carport area and the area between it and the back fence concreted. This improved the useability, but from the perspective of energy efficiency, added thermal mass to the southern end of the house. As this was covered in summer, it reduced the temperature a at that end of the house slightly. Adding a vent to the front of the carport, near roof level, reduced the build up of hot air on warm days.
Paving the backyard area reduced dust and weeds, and also provided some thermal mass. Shading the paving with a marquee meant that we could walk barefoot out in the back garden in high summer, the ground not getting anywhere near as hot as it used to. This drastically reduced reflected and radiant heat reaching the back of the building.
Ceiling fans in the main rooms –
These have made living through summer far more pleasant. Without them we needed our evaporative airconditioner to be turned set for most days over 26C, and if it the outside temperature was over 30C, we needed it set to 4 or 5. I don’t know exactly how much power that used, but it gives a good base for the following comparison.
Now, we can leave the aircon off until the inside temperature reaches 28 and still feel OK, thanks to the air movement created by the ceiling fans. When the temperature creeps up, we now need the it to be set only to 1 or 2.
The fans have made such a difference that we only needed the reverse cycle airconditioner for several hours over 5 days during summer. I can guarantee you that it used to be on for much longer, more often.
Without the lights on, the ceiling fans draw about 70W each.
Low energy exhaust fans in the ‘wet areas’ –
These take only about 4W each to run per hour and, though they don’t move as much air as the old fans, they can be used for longer and still use less power. No, we haven’t fallen victim of the Pareto principle. We have always used exhaust fans to induce an airflow in the house, now we can do it with far less power consumption.
Only one of the old fans still had its details on the motor. These told me that it used 0.3A at 240V. That’s a lot for a small fan. 80W an hour (using the old P= I X E formula). If that was true of all 3, we were using 240W for each hour if we used all 3. Now, we use 12W for the same.
LED lights throughout –
As hardware stores have had sales, we have purchased LED globes for use throughout the house. Except for the ceiling fan lights, we need only about 470 lumens per globe, which seems to require about 5W. This is far better than the old 60W incandescents and even better than the compact fluorescents that we replaced those with, which averaged 18W for the same job.
So now, instead of using 8 globes at 18W (148W) we would use 40W if they were all on at the same time for an hour. The ceiling fans needed two globes each in order to get a comfortable distribution of light in the lounge and kitchen. That meant 14W each. Using 2 globes with limited coverage of light still worked out far cheaper than buying the more expensive (and rarely discounted) globes that have a wider area of coverage.
More efficient appliances –
We have updated our microwave and kettle, purchased an air fryer, pressure cooker and upgraded our solar oven. Unfortunately, Marlon, who is my full time Carer and chief cook, refuses to use them, so the point is pretty moot.The potential is there though.
The death of our old washing machine and the age of our dryer lead us to purchase a new washing machine, one that is far more efficient in water and electricity use than our old one. I’m not sure how much of either the old one used, but the new one has a star rating that is lower than the old, and also features an inbuilt dryer, saving much needed space in our small house. Our old dryer was one of those ancient Westinghouse units that could trip a 10A breaker on a bad day, so we have to be ahead on the power consumption with the new one. The new unit also offers different modes of washing that use less water and power.
Weather seals –
A year or so ago, while we were still renting, we managed to seal all the gaps around the doors (some of which were huge) with readily available weather strips and home made snakes for the gaps at the bottom. This made a very noticeable difference of almost 2C in the lounge during winter and made the bedrooms a little more comfortable.
When we purchased the house, we redid all the seals, and added more substantial and permanent draught excluders for the bottom gaps.We used readily available door seals for the bottom of the external doors, and a home made snake for the laundry door which had a gap that angled between 2.5cm and 1cm, We added the excluders to the main internal doors as well, so we can better compartmentalize the house if we need to. Because of the unevenness of the floorboards, we used the bristle type of excluders for some doors, these are the most forgiving when the gap isn’t consistent throughout the whole arc of the door’s swing.
Whirlybird roof ventilator –
This magical device was installed on the roof early in the piece. We have had them fitted to houses in the past and found them to be an effective way of relieving a little of the heat and improving air circulation.
Roof ventilators help remove the summer heat from the roof cavity and improve overall air circulation, giving a slight cooling effect. In winter they help reduce moisture build up too.
External blinds –
Shading the window glass `and immediate surrounds is by far the most effective way of reducing heat coming through windows. We added cheap roll down shade cloth blinds to all of our western and northern windows. These made a clear and immediate difference. In previous years, with only curtains, room temperature was on average only 6C below the outside temperature, With the blinds on, it now averages 10C lower.
In summer, window glass not only transfers heat into the room, but it can get hot itself. One day, I measured the ambient outside air temperature, the ambient inside air temperature and the temperature of the glass itself. I was given measurements of 33C/26C/44C. Yes, the glass was 11 degrees higher than the air itself. With the blind down, after allowing an hour to adjust, the temperature of the glass was down to 35C.
Block out on all the curtains –
Though it’s not really a recent change, we use 100% block out on all our curtains. Many years ago, I managed to get quite a bit of fabric that was designed for quilt covers.
Jelina attached 100% block out material to the fabric and made them all long enough to reach the floor. The use of the 2 layers of material gives the advantage of a slight and variable air gap between layers and the extra thickness provides even more insulation. These curtains have followed us from house to house over the last 15 years.
Because they reach the floor, they prevent the cycling of air to the windows, which reduces the heating of the air by the windows in summer, and its cooling in winter. I think it’s called ‘thermocycling’. The only way to improve the effect of the curtains is to add box pelmets to the wall at the top of them to reduce airflow even further (another job, another day before winter hits).
Shade sail and marquee –
A friend gifted us a shadecloth marquee that shades almost half of the back of the house. This is a temporary solution before a pergola is installed, but has made a huge difference in comfort in that area. I used it as shade when laying the pavers.
Following the success of the blinds and the marquee, we took the opportunity to buy a 5m X 3m shade sail when it was on sale (puns always intended). This was installed over the northern wall which receives full sun nearly all day in summer. Even though this sail doesn’t cover the whole wall (another job, another pergola), I measured a 10C difference between the temperature of the shaded brickwork and the unshaded bricks.
Lagging on external pipes –
We have external copper pipes for nearly all of our water. The pipes on he northern end of the house were fully exposed to the sun in summer, meaning hot cold water. I bought insulating lagging by the metre as we could afford it and wrapped it around the pipe. This means less water being run off before reaching cold water, and less water going to the fridge or freezer just to cool it to a drinkable, cooling temperature.
Energy wise garden design –
I’ll be covering the garden in detail in another post. For now, I can say that we have almost no reflected heat on the front of the house, the heat being absorbed and blocked the plants and mulch beds built to intercept it. As the trees grow, there will be much less direct heat as well.
Essentially, the trees in the front garden are in two rows. The outer is a citrus hedge that will block incoming wind in winter and sunlight in summer, it will also reduce the radiant heat from the road. The hedge will do this while providing fruit and pretty flowers for us and passers by.
About 4 metres closer to the house are a row of deciduous trees. These will be allowed to grow taller and will provide shade to the house in summer and, in winter, when the leaves fall, will allow sunlight through to the house.
A third row of ‘defence’ has just been started. I have several more deciduous trees growing in pots that will be added to the front of the house in half wine barrels placed directly by front wall of the bedrooms. These will add needed shade, and the cooler air from their soil will help cool the breeze blowing into the bedrooms.
I’ve added sprinklers to the front garden. Though the primary watering is done buy drippers, the sprinkler locations have been chosen to distribute water more effectively to the understorey as well as cooling the air that flows toward the house. I’m not happy with the sprinkler type that I’m currently using and will experiment further.
That’s a lot of work done over 6 months. We probably haven’t seen much of the benefits this year as its been a continuing story of gradual change, but next summer we will see much more, as all the changes will be in place by it’s beginning. As global temperatures climb, efficient power use and passive cooling will contribute more and more to our well being, as well as financial savings.