SteamyTea

A while back, and on another topic, @saveasteading commented about making data files smaller. I did a brief description about that happens, but thought I would spend a few minutes showing some real examples. The data file I used was some electrical grid data from 2012 to 2025, averaged, minimumed and maximumed at the half hour level. This created a large spreadsheet (I know, should be using a database) that was 227,954 rows by 75 columns, with 17,089,587 data points in it. I saved the file in 3 different formats: Comma Separated Value, .csv, a basic text file that is good for importing text based data. Open Document Spreadsheet, .ods, this is the format that LibreOffice Calc uses by default. Microsoft Excel Spreadsheet, .xlsx, as this is used by a lot of people, and probably by far the best spreadsheet package still. I then separately compressed all three files, then compressed and encrypted to see what the difference in size was. Finally I compressed and encrypted all three files into one .zip file. As expected the .csv file was the smallest of the uncompressed files, same when compressed, with encrypting making no difference in size. Compressing and encrypting all three files into one made no difference to overall size. So what have I learnt. No need to compress files individually, better of doing them all into one file, and encrypting makes no difference to size, so may as well encrypt. Results below:

I thought Excel opened them now. I shall save a copy as an .xls and post it up. DHW Cylinder (Excel).xlsx

I was a bit bored on yesterday's car journey, so I started to let my mind wonder onto important things. So I have taken a stab at making a DHW calculator based on cylinder volume and insulation levels. The main points are in the pop out comment boxes. The variables are internal cylinder height and diameter, insulation k-value, insulation thickness, top of cylinder water temperature, base of cylinder water temperature, minimum useful delivery temperature and the room that the cylinder is in ambient temperature (the cylinder base temperature is the same). I am not sure if it is correct, but if anyone wants to check, there is a password in the comments, then you can see the inner workings. Feel free to suggest any changes. DHW Cylinder.ods

It is starting to sound like an Ugandan Hotel.

I could have dropped off that used blue rubber on my way back. You could have fingered some Lumberjack's favourite PU to your hearts content. That will fill the slot and never come off again.

I am ready

Legionella is not the problem, that needs atomised water to get down the windpipe and into the lungs of immune system compromised people. Ghonheria would be a bigger problem after the immaculate and particular folk have had their swingers party.

The worst job I have ever done was cleaning out the spa bath DE filter at the Sheffield YMCA, I have no idea what those young men did in it.

We need a dedicated rant section, similar to Boffin's Corner. Then let our level headed @Pocster be the moderator for it.

That is an inline heater isn't it Yes. Nothing fancy at all. Could be used for inline heating, but at around 2.8 kW, would need a relatively slow flow rate (I could work it out, but can't be bothered). Safety would be my concern. Not sure what you mean. Water will get thinner as it heats, though limescale may make the heating element thicker. I assume you mean Ancient Romans. Maybe this fellow can answer that, ask the right person on here you may get an answer. https://www.youtube.com/watch?v=wmax3ntBS0Q

A Willis heater. Used them all the time for spa baths we made over 30 years ago. Could have a heat exchanger and a Willis in series. A bit about evaporation losses from water surfaces here. https://www.thermexcel.com/english/program/pool.htm Bubble wrap is as good as anything. But make sure no one can get in the pool when it is on.

Try sticking it where the sun don't shine. Always works for me.

I don't, and always manage to get it though his letter box.

Mine has a unique aroma.

The proper term is densimeter. https://www.anton-paar.com/uk-en/products/details/portable-density-meter-dmatm-35-basic/

Water, probably dog's wee. I am passing Bristol in Friday, more than happy to add to the liquid reservoir. More than happy as long as I don't have to pay the congestion charge that is.

Basically yes. You need to disable the cloud service, usually easy to do. You can also, usually, change the default location that different applications saved files to. This is a bit harder. It all depends on the format that the image is saved as. jpg is a compressed format, so compressing it again often makes the file larger as it has to add the algorithm that the compression uses. Formats like bmp and tiff can be compressed, tiff has an option to compress with the zip format built in. Raster images, which are just dots on a grid, can be reduced in a number of ways. You can have reduce the number of colours, say from 32 bit to 16 bit. Increase the number of pixels that get averaged i.e. a 4 by 4 colour, hue and brightness to 8 by 8 average, you loose fidelity though. You can also reduce the number of pixel in the image, from say 1200 wide by 800 high to 600 wide by 400 high. The image is them around a quarter of the size. Again, fidelity is reduced and when you zoom in, it gets very fuzzy. It really depends what quality you need. If it is just for a screen background, you can resize it to screen resolution, and it will look fine. CAD files (vector) are a bit different. By default they are created with efficient algorithms, a start point, an end point and a formula that says what happens between those points, that is why they can be zoomed in on. CAD files do have a lot of other stuff attached to them though, and some formats add just about all the options available, even if they are not used. It is worth getting a copy of Irfanview, as it opens dozens of image file formats, and can save to dozens, it also allows easy resizing and compression. 7 Zip is a good, free, portable compression application that can crunch files, and encrypt them as well. Audio files are a different kettle of fish, they are much more complicated than image files. Though there are compressed formats i.e. mp3. These use a variable 'bit rate' and frequency clipping.

Aviation is really not that bad. If you look at the CO2/1000 km tonne, or even the CO2/passenger km metrics are not too bad. Cement production is similar. Like all things, it really comes down to using them sensibly. IT seems to be obsessed with speed and data transfer. One of the things I used to show my students, 25 years ago, was the difference between the same text as a Word document, a text file and a compressed text file. Why worry about about upload speeds when you can often make the data 50 times smaller.

Is that the same one I posted up last week? There is a good Curious Cases about diamonds. Much more interesting than you would imagine. https://www.bbc.co.uk/sounds/play/m0029rg8

That size is basically a small spa bath. Get a separate ASHP for it and keep it covered. If you get a nice rash on your body, change the water. https://my.clevelandclinic.org/health/diseases/23358-hot-tub-folliculitis

Only one U-Value = 1/ (thickness / k-Value)

I think it is because it is hard to fit it without a lot a time and carefulness. Large steel buildings have roofs that are PU/PIR sandwiched between steels sheets, I think @saveasteading may know more about this.

And find they are governed by the same Laws of Thermodynamics. The real problem is that too many people want to ignore the science.

It really comes down to what you want to achieve with thermal storage. There is energy input types. Input temperatures. Output Temperatures. Output Flow Rates (power). Storage Quantity (energy). Physical size. Overall Mass. Easy of Plumbing. Acceptable Thermal Losses. I have an all electric (E7), small house. My DHW is a 200lt, gravity fed, system that is pumped to the shower. Works fine and has done for 20 years (had to change the old cylinder when it was 20something years old. In all honesty, there is not really going to be much difference, on a small system, whichever type you choose, especially if you only have one energy input type i.e. electricity.