As I noted in my post - there is already BRE approved free software available for those who want to download it

Not if your computer runs Linux(or indeed anything apart from Windows or maybe a mac there isn't. Of the 20-odd approved tools on BREs list _none_ of them run on my computer, or any android machine or any iOS machine or Symbian machine or solaris machine. They might run under wine, or they might not. And most of the demo or free versions of proprietary software has some tiresome crippling done to it (no saving, no printing).

Are there any which aren't too crippled? it would be worth checking wether they work under wine or not.

So the only choice I currently have is is a simple openoffice spreadsheet of the SAP workbook or the energydesigntools site (which in fact doesn't work on my machine either due to the use of proprietary flash and actionscript 3.0 which is not yet supported by free tools. I checked and they have no interest in making it compatible with anything other than Adobe's flash player - at least I did get an anwser).

Still, I guess I should stop wittering and just write something. It does seem like there will be some interest. I'll put it on the list :-)

Wookey - as to the 'no saving, no printing' issue, wouldn't "Print Screen" (depending on the keyboard, sometimes "PrtScr") do it?

Or whatever the equivalent is on the Mac.

vectistim - yes. I have a spreadhseet for the SAP 2005 spec. I started updating it for 2009 but it's not done yet. I'll dig it out, put it online and post a URL

I am a neophyte in the u-value and condensation checker world but I did attend the recent 2 day course in Wufi-pro, the dynamic moisture simulation software.

With wufi-pro which is 1D the input is simple and, of course, you have to take care to get the input parameters right. There is plenty of output graphing and it certainly gives a good guide to the potential problems eg the 1 mm layer of insulation inside plywood placed on the outside of a thick timber stud wall.

There are some materials commonly used here in Ireland for which it is difficult to obtain the required five key parameters that define the material for hygrothermal simulation.

My overall impression is that wufi-pro is immensely useful but needs more to it to be worth the money. A single user license is about £1650- and even an upgrade is £500-! You are paying for a lot of building science but it is a leap.

One clear message from the course is that in terms of the science of moisture behaviour in walls (for vapour drive and capillary action), putting aside the installation issues, external insulation makes sense and internal insulation does not unless you are can justify it by some sort of modelling.

Wufi modelling for a typical, terrible Dublin hollowblock wall with 'upgraded' internal, builder's-favourite, dry-lining insulation gives grim results for the now-even-colder inside of the masonry behind the insulation. Instead of decreasing after build close-in, RH climbs and climbs: mould everywhere and all those joists no doubt rotting nicely; all conveniently out of sight of the inhabitant.

As a beginner it has helped me to go back to first principles. David MacKay in his excellent book http://www.withouthotair.com does the best job I have seen of explaining all the heat loss calcs for a building in simple terms. I made a building u-value spreadsheet from his explanation given the degree-days from http://www.degreedays.net/.

Wufi course was €450- but reduced fee of €315 for registered companies. Excellent trainers for very full 2 days. Need windows to run wufi so for mac need to boot-up as a PC or use Parallels to run windows.

What is the best way to go about beginning to use Therm? Are there any good guides out there on the net? Have not even looked but it is what I would like to look at next.

OK. I found the SAP2005 spreadsheet. It was on my website :-)
http://wookware.org/files/SAPWorksheet9.80.ods
(that's not my work BTW - someone sent it to me)

I'll post here when I finish the 2009 one.

Do please report any bugs you find,

Tom
I could have taken your place, on the course, not the shower floor.
Best way to check for broken ribs is a bit of pepper up the nose, if your chest really hurts when you sneeze, then you know you have broken them.

Get well soon.

I'm bumping this thread in case anyone is aware of any new options that have cropped up in the past year or so.

It seems difficult to find much that is free or inexpensive for those of us on Mac.

Have recently come across this online u-value calculator which I think is quite good as allows you to include the effects of bridging insulation with framing elements and so on, and will update dynamically as you tinker with numbers which I find useful:

http://www.thermalcalconline.com/u-value-calculator/u-value-calculator.html

it would be nice if it included some capability for condensation risk analysis too - I use this (thanks to previous suggestion via this forum) sometimes but it doesn't give you much detail:

http://vesma.com/tutorial/uvalue01/uvalue01.htm

Posted By: rhamdu
wookey, I was thinking mainly of the climatic data: monthly wind speeds and degree days.

Data about the physical world isn't anyone's IP AFAIK, a company recently tried to take the open source repository for timezone data to court for using data from one of their compendiums, but had to drop the case on the (very sensible) basis that nobody owns the rights to the movement of astronomical bodies.

Kaye and Laby is like the Carnot Cycle, you can't get better and I think, for what it is worth, that the GBF members should use it as the standard reference for material properties, saves a lot of guesswork.
It explains a lot of the terminology as well.
Here is a link to the Table of Content:
http://www.kayelaby.npl.co.uk/toc/

Just a shame that you cannot copy and paste into Excel, they move little bit and pieces about to stop that happening, but a bit of editing after gets it all straight.

Shevek,

.... email me what you have got,I will do you a U-value calc and email it back to asap.

Cheers...

To add my tuppence-worth,
Having played with THERM for a brief time and working in a practice where the current focus in terms of financial investment and training is Revit; what would be very welcome in the architectural world is a means to assess a 3D construction detail within the original software package rather than re-draw it using dxf files in THERM. The (hopefully) attached image is the closest I've found to describing what I mean - apparently generated by 'Autodesk Simulation Multiphysics' which, knowing Autodesk will never be cross compatible within their own product line...

I understand that BuildDesk already does a rough approximation of 3D (it appears to just be extruded 2D), but since we are currently building libraries of 3D Revit components it would be mighty handy to give them material properties like thermal transmittance (apparently this feature is due in 2013) and then subsequently analyse an assembly to get a similar output to the one in the picture. Most current U-value software (well the freeware at least) appears to be based around a spreadsheet type input with a similarly impenetrable output of boolean responses to condensation risk queries. Once you start getting into correction coefficients for mechanical fastenings and the like, it quickly becomes more and more of a dark art and you need to know a necromancer who can tweak the coefficients to get the 'right' answer. The beauty of THERM is the more 'literal' output of isobars and thermal flow. For an industry still struggling with the basics of VCL's and thermal bridges I think the more 'visual' the output the better*
* caveat: as long as the data is still mathematically precise and not just a load of pretty colours without a scale...

Sorry, by 'apparently' I just meant that I'd never heard of it before and was reading between the lines - for my part I just did a google search for "THERM Revit" and it was in the results. Similar images I'd seen before were just applying a 2D THERM output as a texture on a 3D model, but the above result would appear (again I'm inferring from the Autodesk website) to model each element fully in 3D and represent 3D temp flows.

Having once destroyed a laptop by trying to run AnSYS for curvature analysis, I'm wondering what the computation requirements would be for this type of calculation - presumably more than your standard U-value or THERM simulation and I imagine too large for Revit to handle 'in-house'. I think the Autodesk Sim Multiphysics software is a standalone tool for engineers who want to model machine components etc. The service you refer to is called 'Green Building Studio' or Autodesk 360 but having tried to upload a complex model we've been working with for about 9 months, you can't currently do much more than say that walls are of 'Heavy' or 'Light' construction and that glazing ratios are about 40% etc...In other words it's a service geared around early stage concept work not 1:5 detailing and as you say is very 'black box' in terms of its operation. Never tested the veracity of the output either.

Regarding the thermal attributes, I agree - couldn't believe this hasn't been around before since it would be so simple to implement, but this website: http://www.aecbytes.com/tipsandtricks/2012/issue61-revit.html appears to confirm what I thought. It does look pretty comprehensive now though, and will perhaps allow more detailed computations to be performed 'in the cloud'.

What I'm really looking forward to though is a seamless link between PHPP and Revit. Currently this appears to be a little way off (there are some issues regarding the way Revit calculates internal exposed wall areas as discussed here: http://www.gduncan.us/?p=756). But there must be some demand for this out there.