[TRNSYS-users] ideal Heating Type in TRNBUILD versus floor heating

[David BRADLEY]

Fahri,
   I would not expect the heating demand to be the same between the two. 
The ideal heating type does not take into account any of the 
inefficiencies of delivering energy to the space. It is simply a measure 
of the amount of energy that has to be put into the space in order to 
maintain the space at a desired temperature. When you look at the floor 
heating component, you have now introduced an inefficiency of the energy 
transfer from the water to the layer in which the pipes are embedded and 
you have introduced a somewhat uncontrollable energy storage into the 
system. I would imagine that the difference between your two numbers was 
largely because of the energy required to heat up the concrete before it 
can effectively transfer energy to the zone.
Best,
  David


On 7/5/2012 04:01, Fahri Avci wrote:
> Dear all,
>
> i have a problem between ideal heating type in trnbuild and floor 
> heating.
> For the two heating systems i use the same building model but the 
> problem is i get two different heating demand values.
>
> The heating demand with the floor heating, which i use NTYPE 59 QALFL 
> is much bigger than the heating demand for ideal
> heating type with NTYPE 30 QHEAT. Actually both have to calculate the 
> same heating demand because its the same
> building construction.
>
> ideal heating type: 13382 kJ/hr
> floor heating: 19262 kJ/hr
>
> My question is why is this so and how can i solve it that both of them 
> have the same heating demand
> (or with a little difference)?
> i think the heating demand with floor heating is much realistic than 
> the other one with ideal heating.
> i don't have any radiator types so i use the ideal heating and try to 
> simulate a heating system with radiators.
>
>
> Thank you for your helps,
>
> Best Regards,
>
> Fahri Avci
>
> TUM München
> Lehrstuhl Energiewirtschaft und Anwendungstechnik
> Arcisstraße 21 München
>
>
>
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-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI  53703 USA

P:+1.608.274.2577
F:+1.608.278.1475
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com



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