UK weather data

[Francisco]

Does anybody know if there is weather data for UK?

Thanks

Francisco

[Browne Dan]

I have quite a few TRY files for the UK. Meteonorm software will create them for you anywhere in the world or you can buy individual files from them. http://www.meteonorm.com/pages/en/meteonorm.php

They come as a .TRY file (test reference year) which does not contain extreme conditions, good for some simulations and not so for others. WUFI also supports WET, DAT WAC and IWC files.

Merry Christmas

Dan

[Francisco]

Dan

Thanks for your offer.

I tried Meteonorm and compared the rainfall data for some locations in Germany with the data for the same locations from WUFI weather data files. The rainfall data generated with Meteonorm was quite less than the rainfall data in the WUFI files.
I am not sure which one is more accurate; I suppose that the TRY files underestimate the rainfall data.

Regards

[Browne Dan]

I think that is the problem with using try files, i'm looking at driving rain and not getting the results i was expecting.

Good luck

Dan

[fostertom]

In recent WUFI Training, the documentation's only comment about Meteonorm is:
"Values for wind and wind-driven rain may be problematic, the distribution of wind-driven rain on the different surface orientations is too even" and
"driving rain based on long-term monthly averages".
However, the teachers said that using Meteonorm is good.

[Christian Bludau]

Hello together,

Meteonorm uses different models to generate climates from weather stations around the selected spot. However there are some things you should know:

• - Meteonorm uses a database of daily mean values (if I remember right) and from that hourly values are generated.
  - The relation between wind and rain is not considered.
  - The model for wind was developed for farming in the US, so the distribution over the direction was not really important.

Because of this reasons, the driving rain calculated from the Meteonorm climate files may be distributed more over all orientations instead of for example the west orientated facade. So if using Meteonorm, it would be good to compare an measured climate file with the generated one concerning the rain.

See the attached picture. Look on the driving rain. Left is the Holzkirchen moisture reference year from IBP, right one generated using Meteonorm. The driving rain on a west oriented facade is about three times lower in Meteonorm.

To get more rain on one of your facades you for example could rise the driving rain factor R2 (for example you could multiply with three in the case of Holzkirchen, west facade).

Regards
Christian

[fostertom]

Christian,do you say that this is the only significant shortcoming of Metoenorm; that otherwise it is good enough, an adequate alternative to obtaining 'real' weather files for each location?

I wonder whether Meteonorm uses similar methods to excellent free http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php# which uses NASA data as well as weather station data, to extrapolate 'intelligently' between (or beyond) weather station locations, for solar irradiance. Though intended for the PV industry, I use it for 'wet' collector and through-window solar. I see that Meteonorm does similar to PVGIS (including uploading your local horizon-shape file)- I wonder which is better.

[Christian Bludau]

Hi Tom,
yes, beside of the rain model we have good experiences with Meteonorm. But you always have to check if the climate is suitable for your concerns.
I do not know the other service, so I can not say how they differ.
Christian

[Matthew Smith]

I have run a few comparative analyses of meteonorm v. measured data files and have come up with similarly alarming discrepancies, albeit with slightly less magnitude of difference (only two locations in the UK - Camborne cornwall and Abbotsinch, Glasgow). It looks like doubling driving rain when using meteonorm would be a good idea, here

Matt

[fostertom]

Christian - it's valuable that you posted the 2 weather 'pictures for Holzkirchen (measured vs Metonorm), side by side. Yes, we can see the difference in driving rain, which you say is important.

But most of the other parameters seem to be significantly different too - yet you say all the rest is adequately accurate, only driving rain needs to be adjusted (or allowed for).

So it's interesting that this degree of 'inaccuracy' in all the parameters (except driving rain) is acceptable. It's good to be given a feel of what's OK!

Am I understanding correctly?

[fostertom]

Hi Dan, and anyone else

What I'd like to do would be to compare genuine UK/Ireland weather files with same location as generated by Meteonorm, to see just what patterns there may be in the differences - and therefore what rule-of-thumb corrections might be applied to Meteonorm files.

Christian says (I keep checking) that Meteonorm files are good enough, except for driving rain. So mainly I'd be looking at driving rain, but judging from the comparative pics above, there may be significant other differences too.

Who would be willing to give (or lend?) me UK/Ireland weather files, to work with? If necessary I'd promise to delete them after use, or to not use them commercially.

[pudding]

Same here, I'm carrying out a self build barn conversion in Cornwall and am currently using the Grenoble wx with the trial version of WUFI to test out some wall build ups. Would love to get a more accurate wx data file of anything closer if possible

[Christian Bludau]

Hello Tom,
I think Joseph has some climate files for Ireland. And he also use Meteonorm. So maybe ask him if you can use his files.
Christian

[fostertom]

pudding, barn in Cornwall - do you live there too? Me nr Exeter - how about seeing if we can find other users, maybe a local users group?