[esp-r] Re: same model gives differents resultas

[Jon Hand]

If the order of the surfaces is different the information in the construction and tmc
files should also probably be different.  Could you be more specific about 'order of surface definitions'?

A difference of 0.02C might just be rounding errors in the simulation.  Actually for two different
tools to produce models that simulate this close is brilliant!

And temperature differences are only one performance metric out of hundreds. Look for
additional confirmation - for example as for a zone and several surface energy
balances for both models.  How do surface temperatures differ?

-Jon Hand
________________________________________
From: esp-r-bounces at lists.strath.ac.uk [esp-r-bounces at lists.strath.ac.uk] On Behalf Of Clément MARCEL [clement.marcel at viherio.fr]
Sent: 03 February 2010 08:36
To: esp-r at lists.strath.ac.uk
Subject: [esp-r]  same model gives differents resultas

Hi all,

I've created a simple model with ESP-r that contains :

- a rectangular zone (3*5*2.7 m)
- an other rectangular zone (2*3*2 m)
- bases of zones are connected to a ground profile (profile 1 in ESP)
- all others surfaces are defined as exterior, except for two (one surface on zone 1 is connected to zone 2 and vice versa)
- all constructions are maded with a 100 mm thickness of insulation material, except ceilings that are a double glazing (transparent construction)
- no internal gains, infiltration, ventilation

I've created this model with the native windows GTK interface (v 11.7). There are no problems with simulation.

I've also created the same model with another software and export it into ESP format. The model exported is exactly the same :

- vertices coordinates are the same,
- surfaces definitions are the same,
- site location, albedo, exposure, ...
- CON and TMC files are the sames
- window native v 11.7

The only differences are :

- for materials db I'm using different version of storage (1.1 for the exported model, no information for the model created manually).
- the order of surfaces definitions is not the same

Can the second point be an explication of the difference of results ? I observe typically a difference in db temperature of 0.02 °C for a simulation on 9 1 to 15 1.
The order can produce differents matrix for theses models, and perhaps explain theses differences ? or is the solver convergency criteria that can produce theses differences ? or the method used to solve coupled zones ?

Regards,
Clement Marcel


--
Clément MARCEL
responsable scientifique et technique
clement.marcel at viherio.fr<mailto:clement.marcel at viherio.fr>

[cid:part1.06020402.06040501 at viherio.fr]<www.viherio.fr>
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26000 VALENCE

téléphone | 0 469 305 202
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télécopie | 0 469 960 594

web | www.viherio.fr<http://www.viherio.fr>

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