4 September 2008 at 4:57 pm #30944Peter DraperParticipant
Does anyone have any knowledge about other weather data for the UK (except Manchester) for the PHPP, or is there an easy way of acquiring it from a recognised source? I am based in Cardiff and so Welsh data is ideal.
6 September 2008 at 1:09 pm #35291Anonymous
Nick Grant answered my very similar question not long ago:
but no Welsh data unfortunately. Plymouth looks to be about the closest.
I believe the lack of fine-grained suitable climate data for the UK is a general problem. I've encountered it before in connection with solar models.
10 September 2008 at 6:54 am #35292
Given the variation in weather for any given location (in the UK especially!) I'm of the uninformed opinion that we need representative weather data rather than fine grained very location specific data.
As I see it the weather data will influence various aspects of design through PHPP (or other model).
eg if it is a cold and sunny climate then more South glazing could be a benefit but if it is a cold and cloudy climate with regular freezing fog then smaller windows could be a benefit. Similar issues when balancing overheating.
ie it is the aspects of the weather data that influence the building format, glazing ratios etc that matter more than the data that sets the exact insulation thickness to meet a nominal 15kWh/m2. We know that adding insulation will reduce heat loss (at a cost) but reducing glazing area (South) might increase or reduce heating depending on climate.
IMHO this sort of variation is more important than say exact degree days in isolation. If we feel that our project is in a location that is 'less mild' than available weather files we can always up the design temperature so that our design is conservative.
What I don't know is how many weather files we would need to reasonably describe the UK or how we would choose the relevant file given that we have weather rather than climate.
The alternative is to produce a weather file for your specific location using Meteonorm but I have no idea how to do that! http://www.meteonorm.com. They offer data sets for a reasonable €50 but I don't know if these are in a form that can be pasted into PHPP. Certainly I heard at the PH conference that Meteonorm can produce output for PHPP.
As discussed elsewhere PHPP uses temperature and solar data to determine heat demand but needs different data generated by PHI using a dynamic model to estimate peak heat load requirement (important if heating with ventilation air only or using air source heat pump).
Whilst some sort of generic algorithm may never happen the immediate opportunity/problem is how to avoid many individuals having to pay for the same data several times.
Might be something that could happen via the AECB/CLP.
Anyone out there with experience of putting weather data into PHPP?
10 September 2008 at 7:59 am #35293
I have learned that the use of Meteonorm is fine for annual energy calcs but there are concerns that it does not allow for adequate consideration of the peak load. I think that this ties in with the discussion with Jurgen at the conference: peak heat load calcs require a data set generated from dynamic analysis considering two design day conditions 1) sunny and cold 2) cloudy and less cold.
(If I recall Jurgen suggested that PHI are developing a more streamlined tool peak load tool that will allow this analysis to happen without Jurgen's own very specific input.)
I agree that more work on the weather data is critical to the national implimentation of PassivHaus. In my view a regional data sets should be adequate.
10 September 2008 at 6:53 pm #35294
You are right about the peak heating load Mark but data should be fine for monthly heat load method.
Anyone know if the €50 Meteonorm data can be pasted into PHPP?
9 October 2008 at 8:36 am #35295David OlivierParticipant
Clearly better dealt with by a revision to CLP Standards, not everyone buying data for themselves.
16 May 2009 at 1:21 pm #35296
I've been meaning ot have a play with Meteonorm as PHI have approved its use for annual heat load calculations based upon monthly data (refer to PH Conf notes from 2008). The peak load calculation however can not be determined using Meteonorm; so using a slightly more onerous site with data for peak loads is recommended. Solar radiation is rounded down in PHPP. This introduced a safety factor which is probably one of the reasons why Meteonorm is considered to be suitably accurate.
Great work. 😉
18 May 2009 at 6:10 pm #35297
Curious to see suggestion that East and West windows can be a useful contribution to solar gain as I have always seen them come out as a net loss.
Does this require a special window spec?
20 May 2009 at 9:31 pm #35298
I think you've got the wrong end of the stick. Rod is referring to geographic east and west coast in Scotland rather than east/west windows.
21 May 2009 at 10:40 pm #35299
Ahh. Have a look at page 13, bottom left slide to see an example of the monthly solar irradiation on surfaces with a range of orientations. You can really appreciate the seasonal variations.
Hope this helps with developing an understanding.
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