In real life I often find that just because I know the right thing to do, doesn't mean that I will take my own advice.
My house was built in 1950 and I purchased it in 1977. It has mostly been neglected, with the odd repair and upgrade. This is a brick vanneer house, early plaster board walls and concrete roof tiles with a ceiling hight is 2.7m.
The house has timber Sach windows, these rattled in their frames whenever a car came into the driveway or on a windy day.
The house also has an open fireplace in the living room, but heating is provided by a gas space heater installed in the fireplace.
The space heater was very, very, inefficient. On cold days, the house would never warm up. The living room was the only room to warm at all and that was because of the radiant heat from this heater.
The kitchen was designed for a fuel stove (chimney), although I don't think one was ever installed. A gas stove of 50's vintage is used.
A house with chimneys mean that the walls have vents in every room.
On hot days the house would cook, very quickly and would stay hot all night.
When it was cold and windy, you could feel the wind blowing through the house.
When it came to making the house energy efficient, what did I do?
The 80's
My first bit of work was ceiling insulation. This was done without much thought. 70% of the ceiling was covered with R2.0 batts. The first thing that I noticed was that the house stayed cold in winter on very sunny days, so at first insulation was a disadvantage. The only positive was the reduction in outside noise.
I also replaced my old gas space heater with a newer more efficient model. The house was much warmer and it cost less to run.
00's
Having old concrete roof tiles that broke easily, I needed to get them replaced. Much to the anoyanc of the tradesmen, I also had sarking installed. They would yell out "I hate this shit" whenever I was in earshot. I didn't notice any difference in heating or cooling the house but I did notice how quiet it became. Rain at night nolonger wakes me up.
10's
The first real effort at addressing the energy efficiency of my house.
I had enough of hot sleepless nights so I had a 7kW split System AC installed. This worked better than I had expected.
I finally got around to having draft seals installed on my Sach windows, and the change was dramatic. Not only did the windows no longer rattle, but outside noise has just disappeared.
With the draft from the windows gone, the house was much cheaper to heat and cool. I noticed that some rooms didn't improve as much as I would have hoped.
The wall vents were filled with bog and painted over. They still look like vents, but no air flow.
When doing the repaint I notices that at the top of the window architraves the plaster had moved away, creating long gaps, 1cm wide in places. Even with gloves on, I could still feel the draft.
I did consider pulling the plaster back and fixing it to the frame, but realised this may cause a lot of damage to the old plaster and very brittle paint, so I just filled the gaps with buckets of Spakfilla.
I also decided to complete the insulation of the ceiling space. This time the entire roof space. I add R3.5 batts covering the previously uncovered areas. About 30% of the roof space now has a double layer with R3.5 on top of the old R2.0. Again the improvement in outside noise was dramatic. It's so quiet inside now that I often didn't know that it was raining outside.
The change to heating and cooling these rooms was dramatic. The whole house is much improved. In winter the house was now very easy to heat and it stayed warm.
Summer is still a problem because the brickwork on the western side heats up and radiates on to the plaster walls, baking the room.
There are two ceiling fans that vent into the roof void, these are in the kitchen and bathroom. The bathroom door is normally closed in winter to prevent hot air escaping, this means that the room is very damp and has a mold problem. The kitchen is part of the dining room, so it cannot be isolated.
As replacing these with ducted versions would be a little difficult at present (asbestos eaves), so I decided to install a couple of draftstoppers. These are simple to install and seem to be doing the job. The bathroom door is now normally open, making it warmer and dryer.
Unfortunately there are still drafts in the house, like the kitchen chimney. This means that the house will stay very warm in winter, so long as it's not windy. These are a lot harder to fix, so they will have to wait.
Solar PV
Have always been a big fan of Solar PV but l'm also well aware of its limitations. Solar PV would only be economical if it was used to supplement my daytime usage, but with nobody at home during the day this would be a problem.
Once I retired everything changed. My daytime usage was now high (heating, cooling, TV and general appliances) so I calculated that it would pay for itself in 10 years if electricity prices stayed the same. As prices have increased since it was installed, I now think I'm looking at a 7 year payback.
I installed 2.5kW on the garage roof, the best available North facing space on the property. The West and East facing areas are shaded by a stink pipe, chimney or a two story house.
This system will produce upto 15kWh a day during summer and 8kWh during winter. I also purchased an in home monitor so that my systems performance and output are recorded.
One thing that I have noticed with Solar PV is that users have no idea if their system is even working. Having a screen inside the house makes it easy to check the systems operation.
Solar HW
I installed Solar HW when the existing system failed, I wasn't going to remove something that worked. The system I chose was 2 FP, 315ltr tank with instantaneous gas backup. Unfortunately the collectors are at half the optimal angle for winter generation, so winter generation is poor.
This system delivers 100% of my HW needs for 8 months of the year. Mostly because of the shallow angle of the collectors, generation in June and July cannot get the water temperature above 40oC, even with full sunshine and no usage. The other reason for the very low gain during these months is the antifreeze system is also in operation over night, which uses the hot water in the tank to stop the panels from freezing.
My reason for choosing this system was that it had some of the best performing elements.
I wouldn't be able to fit an ET system, due to the lack of suitable roof space. The panels were Tnoix, so they had the most efficient selective absorber available.
The Instantaneous gas backup also means I'm only heating the water I'm using and not wasting energy.
Like most installations this was not well done. There was a general lack of insulation on many pipes. Where insulation was installed it was only 13mm. What suprised me the most was that the cold water inlet to the tank had no insulation at all. From the research I have done, mostly in Europe, regard this as mandatory (In Europe tanks are installed inside).
I have since added a lot more insulation to the system.
Solar HW is totally underrated and underutilised in Australia. These systems are very reliable because they have been around forever. The technology is now solid, but there are still manufacturers that are willing to poor quality products.
The only reason I can come up with is that when your HW plays up you know in a hurry. If PV stops working it has no impact.
Unfortunately none of the systems on the market in Australia have a built-in remote monitoring system. This is where the industry is well behind the times.
Water Storage.
I have been looking at adding at least 5,000Ltrs of rain water storage. The only problem is that, much to my surprise, I haven't been able to find anybody in the city who knows how to install a wet system. So I have had to place this on hold as well.
What have I learnt?
Insulation won't do much until you find and fix any drafts, so this should be your first step.
Once you have corrected the drafts, keep adding insulation. Each layer you install will reduce your heating and cooling costs.
The additional advantage in insulation is its impact on noise from outside the house. It doesn't matter that it's bulk batts or thin foil, each additional layer will provide noticeable noise attenuation.
If you have gone to the trouble of reading this far, thank you. I would appreciate any comments, good or bad you may have.
