Fabric and ventilation heat loss calculator

[Grendel]

On 15/06/2016 at 22:23, JSHarris said:

Ages ago I wrote a spreadsheet for doing what-if comparisons to see whether it was better to invest in more insulation in the walls, roof, floor, fit better windows and doors, or fit a better MVHR system.  Others have found it useful and I've been reminded that I've not re-posted it over here, so here's the latest version.

It should be self-explanatory, you fill in the cells with your wall, roof/ceiling and floor areas, add the areas of each door and window, put in the U values for each and, if you can, get hold of the met data from the met office for your area (the data in there is for West Wiltshire, right on the border with Dorset).

This isn't a thorough modelling tool, it just looks at heat loss fairly accurately but doesn't take into account heat gains, although there is a crude way of doing that by drawing a line across the seasonal plot at the point where you don't use heating and you can very roughly assume that anything above that line will be heating.

Please feel free to ask any questions, but bear in mind I wrote it back when I was designing our house and haven't used it for a couple of years. so I may be a bit rusty.

Note that the file is an Excel spreadsheet, but to get the forum to accept it a an attachment I had to rename it with a .txt suffix.  Download it, then edit the name so that the ".txt" is replaced with ".xls" and it should work.  I have a Libreoffice version as well, if anyone would prefer that, although Libreoffice will open and run the Excel file OK.

Fabric and ventilation heat loss calculator - Master.txt

Does anyone have a working copy of JSHarris heat loss spread sheet?

I've tried changing the .txt to .xls but it tells me it's a corrupted file and wont open.

thanks if you have ?

[Jeremy Harris]

2 minutes ago, Grendel said:

Does anyone have a working copy of JSHarris heat loss spread sheet?

I've tried changing the .txt to .xls but it tells me it's a corrupted file and wont open.

thanks if you have ?

 

 

I've just tried it, downloaded it from the link, edited the suffix and it works fine, both on a Linux machine (opens in LibreOffice without a problem) and on Windows machine, where it just opens in Excel.

 

Here's the link again, just in case it's a link problem:  Heat loss calculator - Master.txt

[Grendel]

thanks JSHarris - I get

 

I'll try again

 

 

[Grendel]

All sorted - it was the way I was doing it (wrong)

thanks

[Grendel]

Does anyone have the more complex Fabric and ventilation heat loss calculator - Master.txt  ??

thanks

[Jeremy Harris]

56 minutes ago, Grendel said:

Does anyone have the more complex Fabric and ventilation heat loss calculator - Master.txt  ??

thanks

 

It isn't more complex, it's the same spreadsheet, just with an error corrected in one of the cells.  I just renamed the file to give it a shorter file name when I uploaded it here, rather than hosting it on my own website (finger trouble I'm afraid - I need to sit down and sort out why Wordpress has corrupted the file database on my site and try and fix it).

[TerryE]

On 16/08/2018 at 15:15, JSHarris said:

Not sure what's happened, but it looks like the database has somehow got corrupted - anyone that knows how to fix Wordpress when it's broken would be useful

 

I do, but only after you've had that sysAdmin chat with me ?

Edited August 26, 2018 by TerryE

[Cpd]

Ok....... trying to download this latest version onto my iPad......but to no avail. What am I doing wrong ? (Except not owning a normal computer.....) 

[Jeremy Harris]

Does the iPad have a spreadsheet app as standard?  Not sure it does.

 

The calculator is a spreadsheet, and will run in pretty much any spreadsheet programme, as it doesn't use any functions that are specific to a particular company's product.  It runs fine in Microsoft Excel (all versions since 2003), all versions of LibreOffice Calc, Open Office etc.  Pretty sure it should run on the version of Excel in Office 365, too.

 

I'm afraid I know little about Apple stuff, but do know that there's a version of Excel that runs fine on Apple Mac machines under MacOS, so it should run on that.  I've no idea if there's a spreadsheet app available for a iPad, I'm afraid, as I daren't go near my wife's iPad to find out!  I would guess that it won't be that easy to use a spreadsheet on a tablet device, as the chances are the keyboard will end up covering the parts of the screen you want to see a lot of the time, and you'll need the keyboard on screen a lot to change data in the various user-input cells.

[Jeremy Harris]

Just had a quick look and it seems there are several spreadsheet apps for the iPad.  No idea whether they would work OK or not, but the quick ones I've found are Numbers, Free Spreadsheet and Excel.  I'd imagine that using them on a tablet may well be an exercise in frustration though, as one key thing with any spreadsheet is the need to see the screen whilst entering data into cells, so without an external keyboard I'd guess they are likely to be a bit awkward and very slow to use.  Any of them should be able to accept an .xls file though, as it's a very old standard.  If you need it in another format I can upload in a pretty wide range of them, I'd just need to know what file extension any programme expects to see.

[willbish]

Just a rookie question to check I'm entering my data correctly; is the internal floor area required in cell B21the footprint of the groundfloor only?

 

Then to calculate W/m2 (for UFH), I take the Total Heat Loss value and divide by the heated floor area, which includes ground and first floor?

 

Many thanks

[Jeremy Harris]

1 hour ago, willbish said:

Just a rookie question to check I'm entering my data correctly; is the internal floor area required in cell B21the footprint of the groundfloor only?

 

Then to calculate W/m2 (for UFH), I take the Total Heat Loss value and divide by the heated floor area, which includes ground and first floor?

 

Many thanks

 

 

Yes, the floor area is just the internal ground floor area, the bit that can lose heat to the ground.

 

Again, yes, taking the total heat loss and dividing it by the floor area will give you the very worst case UFH output per m².  In practice the house will have incidental heat gains from people (roughly 100W each) electrical appliances, heat losses from the hot water system into the house, cooking, solar gain and even pets, so this really is the absolute worse case heating demand, with everything except the UFH switched off and no one in the house, with no solar gain.

[joe90]

I love my iPad for day to day stuff but I have a “normal” laptop for proper computer work,I.e. spreadsheets.?

[Triassic]

I the Heat Loss Calculator still available? All the above just give error messages?

[Jeremy Harris]

9 minutes ago, Triassic said:

I the Heat Loss Calculator still available? All the above just give error messages?

 

That's odd, I wonder what went wrong with that attachment link?  Here it is again (as before, rename the file to change txt to xls):

 

Heat loss calculator - Master.txt

[jack]

3 hours ago, JSHarris said:

 

That's odd, I wonder what went wrong with that attachment link?  Here it is again (as before, rename the file to change txt to xls):

 

Heat loss calculator - Master.txt

 

Interestingly, I just downloaded this. Previewed fine in file explorer (Win7 box) but said it was a corrupted file when I tried to open it.

I shut down Excel (I'd had another file open at the time), tried it again and it worked fine.

[Hobbiniho]

iv downloaded your heat calculator but im confused as to how i go about renaming it, if i just right click on it and click rename it just leaves it as a text file

[Declan52]

18 minutes ago, Hobbiniho said:

iv downloaded your heat calculator but im confused as to how i go about renaming it, if i just right click on it and click rename it just leaves it as a text file

Keep the name as is but change the .Txt to .xls.

[Hobbiniho]

1 hour ago, Declan52 said:

Keep the name as is but change the .Txt to .xls.

when i right click on it and click rename it doesnt show .txt it just highlights the name

[ProDave]

58 minutes ago, Hobbiniho said:

when i right click on it and click rename it doesnt show .txt it just highlights the name

What OS?  

 

Some like to mollycoddle you and hide the extension so you can't mess with it. You probably need to change some settings.

[Declan52]

Type it in with the .Xls

[Jeremy Harris]

As @ProDave says, Windows from around Win 7 onwards had a default setting in the file explorer that hides the file extension, probably one of the most irritating and annoying things Microsoft have done in recent years.

 

To change this, so you can see file extensions, then you need to go into a menu (often options) and then select something like "advanced options" where the system deigns to give you the option to actually see the full name of files that are on your system.  I can't give the exact instructions for all versions of Windows, but there will be an option to unhide file extensions, and that should then show the full file name and allow the extension to be renamed.

[ProDave]

And while you are at it, unhide "hidden" and System files.

[Ferdinand]

8 hours ago, ProDave said:

And while you are at it, unhide "hidden" and System files.

 

I normally leave those hidden as far too easy to delete by mistake otherwise.

 

Do Microsoft still have Delete next to Rename in the Right-Click menu?

[Hobbiniho]

ok thanks guys, im at work so its windows 10 got it sorted now cheers, just have to figure out the u values now