[esp-r] Re: Underground temperature?

[Achim Geissler]

Dear Marco

 

thank you for the information. That is how I also understand the climate
data is generated (actually, for Germany, it is usually a mix of
measurements over many years and some "statistically generated" data). But,
air temperatures etc. then also do not take any buildings (or cities, dens
construction sites etc.) into account. So we have the same issue here.

 

I would assume that any model using ground temperatures should in some way
take this into account. The data can only be for "uninfluenced ground",
because the data cannot (should not) include any building influence as this
will depend on how deep the building reaches and how well it is thermally
insulated from the ground (among other things).

 

The "stat" file says "do not use for 'GroundTemperatures object'" but also
says  

   -   The temperatures for 0.5 m depth can be used for
GroundTemperatures:Surface.

   -   The temperatures for 4.0 m depth can be used for
GroundTemperatures:Deep.

 

which seems to refer to a specific calculation model / procedure.

 

Just my 5 cents .

 

Best regards

Achim

 

 

-----Original Message-----
From: Marco Manzan [mailto:manzan at units.it] 
Sent: Mittwoch, 30. September 2009 09:06
To: Achim Geissler
Subject: Re: [esp-r] Re: Underground temperature?

 

I know as the climatic data for italian sites, that form the IGDG database, 

have been collected. The data is obtained averaging over a period of about
20 

years air force measurements on airfields on a number of sites. I think 

ground temperatures are obtained using a conduction model for the soil and 

are not measured. The conduction model clearly does not take into account
the 

presence of buildings, so the obtained temperatures are valid only for free 

field problems, perhaps they can be used to assess the risk of freezing for 

underground piping.

An alternative method for dealing with basement losses is to use the method 

included in ANNEX D of standard ISO EN 13770.

Furthermore I know that esp-r can deal with basement losses solving a 3d 

control volume for the ground, I never used it and I think it is among 

the "hidden" and undocumented features of esp-r.

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.strath.ac.uk/archives/esp-r/attachments/20090930/688082ad/attachment.html