Blog entries from June, 2024

Today is the winter solstice and over the last few days it has been quite clear that winter has set in in Melbourne with headlines such as “Melbourne shivers through coldest winter day in four years…” so it seems appropriate I give some updates on how my solar, AC and heat pump hot water system are going.

A big question I asked myself was whether I made a mistake in getting my gas disconnected. Previously I would have the central heating on a schedule that I didn’t think about and my entire house would be warm at the times that I was awake. The AC units in my study (during the day while I am working and then in the evening) and bedroom (a bit in the morning for when I wake up and then a bit in the evening before I go to sleep) do a good job if I close the doors to those rooms, which means the other rooms (kitchen, bathroom, lounge) are cold.

It isn’t actually that bad, but it is noticeable when I move from room to room. Thanks to my monitoring I could also track that when I was in my study that the CO₂ would climb to 1500ppm and at times I do feel a bit sluggish. My mitigation so far has been to get up every hour and go get a drink or go to the bathroom, this lets enough fresh air in to drop the CO₂ down to around 600ppm from where it will start to climb again. The alternative is to leave the door open (like I used to do) but then the AC unit is trying to heat my entire house which is not efficient.

With the shorter and cloudier days there has been a noticeable drop in how much my solar panels are generating. At the peak of summer they would generate almost 30kWh over the day, but the best I have seen recently is 17kWh on a day that was sunny all day, but that is the difference between 13 hours of sun high in the sky versus about 8 hours of sun that is lower. Though even on a day that rained all the way through the panels managed to produce around 3kWh which was about a third of my consumption for that day.

I could also notice a pattern of the solar generation being best in the early afternoon, the day would start out cloudy and the clear up for a bit. To better take advantage of this I changed the schedule on my heat pump hot water from 10am to 1pm with the intent to run it both from solar that I am generating and also to be in a warmer part of the day so it should run a bit more efficiently. I don’t have a way to actually measure this, but it seems like the right thing to do. What I can also see is that where it would run for just over an hour when the ambient temperature was above 20°C, but now when the ambient temperature is below 10°C it is running for a bit over two hours.

All of this is just the detail, what really matters is the long term so it won’t be until the start of next year that I can sit down with the data and compare 2023 with gas heating and no solar against 2024 with solar and three heat pumps…

My house was built in the early 1970s but fortnuately the previous owners had redone the kitchen, bathroom and a few other things, including removing the gas heater from the lounge room. They didn’t remove the faux chimney breast (I assume because it may have been partially supporting the hot water system in the roof), instead converting it to an alcove with a passthrough to a wall mounted tv.

When I picked up a television at the end of 2020 I chose a 40″ model and mounted it. This is how it looked for quite some time:

This tv did fail once before due to a failed power board related to the backlight. I opted to have it repaired as I didn’t want to go through the hassle of finding a new tv.

A few weeks ago that hassle finally arrived, the tv failed again, this time the fault was frozen/corrupted picture a few minutes after being turned on. As this was now over 13 years old I reasoned that it was time for a replacement.

This search was the hassled I was expecting.

Due to where I have the tv mounted I didn’t want anything too big, I wanted to keep it within the width of the chimney breast. I also wanted it to be quite thin, keeping it as close to the wall as possible, like the previous tv. Then there was the matter of what “smart” features it had and how annoying those would be. I wanted to continue using Kodi on a Raspberry Pi to watch media, not anything built into the tv.

In the end I got lucky and found a Samsung tv that was 43″ (with narrower bezel so the same outer dimensions as my old 40″) and quite thin (even thinner than my previous tv). It was also from last year so the places that still had stock were selling it with a significant discount.

I wasn’t able to reuse the previous slim wall mount, but that was handled by spending $50 at Bunnings for a simple slim mount. I am quite happy with how close it is mounted to the wall, even after using spacers so that cables could run past the bracket:

When I first turned the tv on I was stunned at how bad the included remote control was. It is a horrible mess of a few unlabelled buttons that might be touch sensitive, or they might just not work consistently. Then I realized something, my old tv was a Samsung and this new one is also Samsung… so for most functionality the remote from my old tv was significantly easier to use. This also meant I did not have to completely reprogram my universal remote, only update the inputs used for the different activities.

While this tv does have wifi, it also has wired ethernet. Initially I did connect it to the network so it could run updates, but I didn’t sign in to any services and I then unplugged it. This gave an unexpected improvement in regard to free to air broadcasts and the Freeview service.

If you turn the tv on and switch to the DTV input you can watch broadcast tv, changing channels is quick and the overlay is in the Samsung style. But then after about a minute or so (if connected to the network) the interface will swtich and now when you change channels it is showing Freeview branding and it takes about 10 seconds per channel. You can also bring up two versions of the tv guide and the interface is a general mess. I rarely watch broadcast tv that often, but when I do I want the basic functionality that works…