Monday 23 July 2018

Solar Floor Heating (again) (part 1)

Well its been a while since I moved in here, and the first winter was almost over when I bought the place. I busied myself with other more pressing issues (like a car space, fixing some plumbing) and after some time needed to go back to Finland (which is chronicled here as well).

So I've managed to stop procrastinating (a bit late) and have started the project to make the house both warmer and less of an energy hog.

As in my previous project I'm installing first "under floor" heating and some insulation under the floor to do what I can to bring up the interior temperature duing the day by transporting in what heat is available outside. This is best done by allowing solar to heat water (in pipes) and move it under the floor. See this post for a series on that project on my old house.

So basically this time I'm going to show a bit more of what I'm doing in installing the pipes, because that was missed last time (because I was fucking busy doing it and forgot to photograph it, this time I'm taking my time a bit more)

This is a typical "raised on stumps" Queenslander, built in the 1920's, so my underf-loors are easy to access (with a bit of head bashing involved. This is a shot of the place from the back yard (from when I inspected it before buying).


The house is on a sloping block, so the back is higher off the ground than the front. So its relatively easy to get in under it and work on the floors, which of course look like this:



This is from under the "house proper" looking back the opposite way to the above shot. Here you can see that there "back filled veranda" has a different arrangement of floor joists to the rest of the house ... which isn't exactly regular anyway.

This makes planning the run of pipes interesting, but not impossible (assuming I wanted to heat that area, which I do because that's my kitchen / dining area). Looking back "up hill" to the street we see the area of the "house proper" (as I call it) with a black water pipe being visble leading to the bathroom on the left (as viewed in this picture).


 Of course the bathroom has had some water damage over the years:


it looks visually worse than it really is, and some of the bad stuff has been cut away and replaced, or supported. This is the beauty of hardwood houses, you can see exactly what's what and repair is simple and mostly inexpensive (compared to a concrete slab house).

This is a sample of how I run the pipes:


with them "held" against the floor at first just by a cable tie and a staple like this:


Its fast to install, ample to support the small weight and only for install purposes because soon I'm going to be fitting in polystyrene so that it fits under the pipes (thus sandwiching it to the floor) between the joists. This will then be "capped off" with standard sarking (usually used on walls and rooves). This will air seal the pipes and their insulation (but allow humidity to transpire out) giving better transfer into the floor, and reduce losses in the evening and when windy.

Last time I didn't  bother running the pipes "through" the joists, but instead looped them around by going "under", however this time because its so much colder in the evenings and windier here I'm doing it this way.

Similarly to last time I divide the floor into two halves, and each half has its own pair of circuits of water flow. This gives two pipes between joists (which my earlier experiment revealed to be sufficient) and results in shorter runs for the small pumps to push the water through.


As you can see (if you look carefully) I run the flow of each circuit in the opposite direction, so that as each direction starts warmer and sheds its heat the other does the same in the opposite direction ensuring more even temperature.

The pipes from each circuit are gathered together and run towards the junction box where water from the floor meets the water from the solar collectors.


Here you can see that some are going through the joists (which are actually looping back as part of another circuit) and some over the joists (going straight to the junction box).

This is where the project rests at the moment ... I'll continue adding posts as progress occurs find-able under the tags of "solar" and "home improvement". That gives me a record of what I'm doing for me too. After all blog comes from log and this log is also for my own reference too ...

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