Hot and cold

Tuesday, October 24th, 2023 at 06:33pm

Continuing my thoughts on the cost of heating I have been running through different ways of thinking about what my house is and what I would want in regard to heating and cooling.

So what is my home?

  • A two bedroom unit that was built in 1970.
  • Insulation in the ceiling, but not in the best condition and should be replaced. No insulation in the walls or floor.
  • No windows facing east so don’t get any morning sun.
  • My lounge has north facing windows, but no significant heat comes from those.
  • Both bedrooms have west facing windows (so they get the hot afternoon sun)
  • The bedroom I use as my study had a north facing brick wall that heats up in summer.

What do I have for heating and cooling?

  • Gas central heating.
  • One bedroom has an ancient in-wall air conditioner that I never use.
  • Ceiling fans in the bedrooms and lounge.
  • Venetian blinds on all the windows.
  • External blinds on the west facing windows.

What is a day like in winter?

  • It is cold and dark outside.
  • Central heating warms everything up quickly.
  • I have the heating first set to 16°C to help me wake up, then warmer for the remainder of the day.
  • It is comfortable to work in my study or be in other rooms.
  • The afternoon the sun might hit my study window enough that I will close the venetian blinds.
  • Once the heating turns off it looses head fairly quickly, but I am asleep by then.

What about in the peak of summer?

  • It is more variable, often overnight in the teens and mid to high twenties during the day, but then periods of hot weather were is is above 30°C at night and over 40°C during the day.
  • Most of the time it can be comfortable with the external blinds to blocking the sun and then the ceiling fans circulating air.
  • When it gets hot then everything starts to heat up and then stays hot for a day once the cool change eventually comes through. It did get to 40°C in my study once, but it is hard to work in anything above 30°C

For now I am setting aside the issue of insulation and keeping my focus on active heating/cooling as that has a much more tangible impact in the form of bills. I would like to insulate the walls and re-insulate the ceiling, but that will be long term.

Something I have tried when the house is hot and a cool change has arrived is to open up doors and windows to try and get a draught, but that has never worked very well. The idea of a whole house fan has intrigued me, but while a thing in places like the US, it is rare in Australia. A couple of companies do install them, but none I have found in Melbourne.

So what I am after is a way to make things comfortable throughout winter (such as heating the study to 20ish degrees while I am working), and then make the extremes in summer tolerable (getting from the high 30s to the mid to high 20s).

While ducted air conditioning would be nice as it would be unobtrusive (unlike the the indoor head of a split system), the additional cost (double, quadruple, or more…) is not as appealing. It would also be heating/cooling rooms that I am not spending time in, so without better insulation that would be a wasted running cost.

This line of thought is taking me to split systems which would have the advantage of being able to cool the specific rooms that need it AND the room that I wish to use at the time. While there is more it learn about these specifically, it is also bringing me back to electricity, when does it get used, how efficiently is it being used, and where does it come from?

More electricity used during the day means that solar panels will be more beneficial…

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