Split System Heating and Cooling

As I mentioned in my previous post, we have now created a heating and cooling zone in our main room by rebuilding a wall and fitting a door. If we’re inside during the day we spend most of our time either in this room or in our study, so converting our heating in this space to zero emissions sources will put a significant dent in the emissions generated in our home.

The heating unit that we decided to go with is a heat pump, alternatively known as a split system or a reverse cycle air conditioner. Switching to this technology is ranked #42 on Project Drawdown. In traditional heating, you can convert one unit of energy into one unit of heat. With a heat pump you aren’t creating heat so much as moving it from one place to another, which means the heat output can be significantly higher than the energy input. This is the same concept used in refrigeration.

Heat pump heating and coolingEfficiency varied considerably across the units that we looked at. We decided to go with the most efficient unit that we could afford, and were quite surprised by how many units cost more with lower efficiency. We went with a 5-star Mitsubishi unit that we bought at Bunnings. Heating is rated at 3.2kW output for 0.65kW input, and cooling is rated at 2.5kW for 0.51kW input. Our unit is considered too small for the space, but we wanted to size it against our solar panels instead of our room size.

Our hope is that installing this unit will mean that we no longer run the gas ducted heating at all in a best case scenario, or only on the coldest days in a worst case scenario. In either case, we expect our heating bills to be slashed. By switching to electricity we generate ourselves instead of using natural gas, the unit will potentially pay for itself in fuel savings before it is out of warranty.

If you’re playing along at home…

…how much could you increase the energy efficiency of your home by switching to a heat pump for heating and cooling? If you already have a system for cooling, how much gas could you save by also using it to heat? Please share your experience in the comments below.

Create Heating and Cooling Zones

At some point in the past, our house has undergone a series of renovations to combine three small rooms into open plan living. While we really enjoy the bright spaciousness of our main room, having it open to the hallway meant that we couldn’t shut off this part of the house to separate out heating and cooling zones.

The benefit of separate heating and cooling zones is that you only have to heat or cool part of your house instead of the entire building. By only adjusting the temperature in the part of the house that you are using, you can save a significant amount of money on heating and cooling costs, and the energy use that goes with it.

Door with glass panelsWe were able to separate our main living area from the hallway by rebuilding the wall that had originally separated the two spaces. This was the wall where the cornice had fallen down, leaving a gaping hole in the ceiling. It was an opportunity to create something better than what had been there before, so we widened the doorway and chose a door with glass panels to retain the natural light in our hallway.

The whole project cost us approximately $600 to complete, and it has made such a difference to the temperature in the house. On colder nights we shut the door, and the heat generated in the kitchen is enough to keep the room warm. During a recent hot spell we kept the door shut, and it stopped heat from flowing through our large, north facing windows into the cooler bedrooms. This passive difference isn’t huge, at only one or two degrees, but already it has been the difference between running the gas ducted heating system and not running it.

If you’re playing along at home…

…are you able to create zones in your home to reduce the amount of energy required to heat and cool the space? Please share in the comments below the approach you took and the results you achieved.

Turn Off Pilot Lights

Our home currently has three gas appliances: the stove, the ducted heating, and the continuous hot water system. We’re focusing on other projects around the house first, which means that we haven’t got the budget available to replace these with electric versions.

The easiest – and cheapest – way that we could find to make an immediate difference here was to turn off the pilot light for the hot water system. There is a flame that burns continually, and the system increases the flow of gas as water is being used, so for 24 hours each day we were using gas.

When we looked at our water usage, leaving the hot water system turned on didn’t make much sense. There are four people living in the house, and between us we might spend at most half an hour using the water to shower and wash the dishes. That means for more than 23 hours each day we were burning gas for no point whatsoever.

Gas water heater

Our system is inside on the laundry wall, so we don’t have to go outside to use it. There is a button to press to turn it off and you have to press a whopping two buttons to turn it back on. The final button allows it to heat up to the set temperature. It’s a remarkably simple system and takes only a few seconds to set.

Beyond the bigger climate picture and our gas bill, turning off the pilot light is important because this is carbon that was being emitted inside our house. Carbon levels above 1,000 parts per million (ppm) can have adverse effects on human health, ranging from headaches and difficulty concentrating in the short term to changes in bone density and body metabolism in the long term. That might sound like a high number – outside levels for September were 408.55 ppm at the Mauna Loa observatory – but levels can easily pass 1,000 ppm inside closed environments such as offices, classrooms and homes.

If you’re playing along at home…

…do you have any pilot lights that you can turn off when they aren’t in use? Please share in the comments below ways that you have reduced passive fossil fuel use around your home.

Insulating Behind Wall Panels

As part of our solar installation, we needed to get the asbestos removed from the work site. The main areas were our electrical switchboard and the eaves under the roof. We also had two asbestos panels beside the front door, and the company was willing to add those to the job for free. With the exception of the asbestos flue for our hot water system, this now means that the outside of our house is asbestos free.

We saw the removal of those asbestos wall panels as a great opportunity to check the insulation of our external walls, and there was no surprise at all that they were just empty cavities. Walls in this area should have a minimum R insulation value of 2.8 and, since this is a north facing wall, we wanted to go as high as we could.

Adding insulation to the wallThe highest insulation rating that we could find was R 7.0, and we had to get it as a special order, which only took a few days to arrive. We had the right amount of insulation to do the job, but we hit the first obvious hurdle – it didn’t fit. The batts were so thick that it took three adults to compress it inside. Unfortunately, when you start to compress this type of product, you also start to reduce the R rating.

After a quick strategy meeting, we agreed to carefully split the batts down the middle to make them half the thickness. This had the unfortunate effect of reducing their R rating, but it did mean that we could get them in the wall.

Given the price of this insulation, we would have been much better off measuring all of the internal dimensions before choosing a product, so I’m glad that we made this mistake with a smaller quantity instead of buying enough for the whole house. The surplus insulation has been put in the roof where it will be used to patch any gaps once we have a chance to get up there.

If you’re playing along at home…

…do you have any external panels like these that you could remove to add insulation to your external walls? Please share in the comments below if you have made similar modifications to your house and how it went for you.

September School Climate Strikes

As part of the global climate strikes on 20-27 September, I took our eldest daughter out of school, collected the little one at lunch time, and together our family went to the Melbourne rally. For the kids this was probably one of the most exciting things we’ve done all year – they got to go on a train, wave posters, chant with a large crowd, and all in exchange for catching up on the missed classwork over the school holidays. For us parents it was also a bit exciting – preventing our toddler from whacking people with her poster, getting separated in the crowd, and realising half way there that we forgot to bring the baby wrap.

Melbourne Climate Strike September 2019

In response to the strikes, I spent one or two days reading comments that the children should have been in school learning instead of being out and participating in democracy. Those arguments faltered and vanished fairly quickly, and were replaced with astonishing observations that it wasn’t older generations who are responsible for climate change, but younger generations with their rampant consumerism and materialistic ways.

Who do you think taught them to be that way? We did. The generations they looked to for an example.

With the strikes our leaders complained that children should be in school learning, and the response from our children was that there’s no point learning if we don’t act on what we teach them. To instead complain that our children are part of the problem when they are doing what we have taught them to do is just astonishing.

If you have been able to watch the speeches during the youth protests without feeling a degree of shame then either you’ve cleaned up your act or you don’t realise how dire the situation is. I’m incapable of watching Greta Thunberg’s UN address without crying. I imagine my little girls in her place in a decade, a time in which it will be too late to do anything but stop the disaster from worsening further, and I realise how complacent I have been since the day I became old enough to do anything about it.

There’s an interesting thing about shame; you can either lash out at those who make you feel it, or you can do something about it. Based on my Facebook feed, a lot of people who I thought knew better have chosen the lashing out option. I understand, because it’s very difficult to look at yourself and acknowledge all the ways in which you have failed. It takes a strong person to stare at the truth and see it as a call to action. There is tension in knowing that the time to correct past mistakes is almost over, and an incredible fear when you realise that nobody can tell you the quick solution to make that correction.

Our own parents aren’t coming to the rescue, and the true shame is that our children are starting to realise that about their parents too.

When the children of the world asked adults to strike with them this time, there was no way that I was going to say no. We might not be able to do much as individuals, but we can accomplish beautiful things as a collective. In a decade from now, my eldest will be Greta Thunberg’s age. When she asks what we did, I can tell her about the changes that we made to our lives, and I can also tell her that for one day we stood up as a family, we made our voices heard, and we joined in with something bigger than ourselves.

Melbourne Climate Strike September 2019

If you’re playing along at home…

…did you and/or your children attend the climate strike? What did you learn through the experience?

Solar Panel Installation

On Monday last week we were able to complete the first major piece of work on our journey to becoming carbon negative: our photovoltaic system was installed.

Solar panels on the roof

We have 10 panels on our north-facing roof for a combined capacity of 2.75kW. The power company estimates that we will generate an average of between 5.62 – 11.82kWh electricity per day, as per the table below:

System Performance Estimate

Based on our electricity bills, our daily generation will either cover or surpass our daily usage. This means that we will be either carbon neutral or carbon negative for our electricity consumption throughout the year. The electricity that we don’t use will be exported to the grid, which will help the it to reduce its emissions by a tiny amount too.

The electrical inspector came by on Tuesday this week and turned on the system for us. We still need to sort out the changes to our electricity plan so that we are paid for what we export to the grid, but from the environmental perspective we are done. We got dressed up, we went out, and we celebrated.

If you’re playing along at home…

…have you installed solar panels? Please share in the comments below how much of your electricity usage you were able to generate yourself.

Reflecting on One Year of Climate Action

1[1]Tomorrow marks the first anniversary of this blog, and I wanted to use it as an opportunity to reflect on our mission to change our carbon emissions to an overall negative level. We’ve learned a lot in that time about climate change and, equally importantly, we’ve learned a lot about ourselves.

We can’t do everything at once

It’s all well and good to say that we’re going to stop contributing to pollution tomorrow. In practice, the only way I can think of to achieve it that quickly is death, and I’d rather downgrade that solution to Plan B (or Z). So much of our culture is based upon technologies and resources that harm our planet; the scope of the problem is so huge that if you tackle it all at once you’ll burn out quickly and end up in despair. It’s better to make one successful change at a time than to attempt fifty and succeed at none of them.

We’re more powerful than we knew

We don’t need to rely on governments to start making positive changes to the way we live our lives. If we want to plant some vegetables to reduce food miles or recycle our soft plastics instead of sending them to landfill then we have that power. We might not be able to do much at a global scale about climate change, but that certainly doesn’t limit the things that we can do at home. Taking control of our actions and being proactive tends to spill over into other areas of our lives, and that’s a great bonus.

The faster we change the easier it becomes

There is a carbon budget that is discussed in climate change models. This budget is the amount of carbon that can be released into the atmosphere before we reach key levels of temperature increase. One of the biggest problems with the climate budget is that nobody knows exactly what it is. I could spend days researching the exact levels predicted by different models, or I could simplify it all to a simple truth: the less we pollute today, the more wriggle room we have tomorrow. Making choices now that reduce our emissions means our children will have more options for further improvements.

Sometimes you take one step backwards so you can take two steps forwards

Earlier this year I spent a few months working full time out of the home. The cash injection was significant for our family, but I felt very uncomfortable about how long I spent behind the wheel every day in order to get to work. At a time when we were trying to reduce our emissions I was going out and increasing them, and it felt hypocritical. We used that additional income to fund changes around our house that will permanently reduce our emissions. The additional emissions might have been philosophically unpleasant, but I estimate that those reductions will compensate for them within 1-2 years.

If you’re playing along at home…

…has attempting to tackle climate change taught you anything about yourself or the world around you? Please share in the comments below what has captured your thoughts in this process.