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Same temperature in rooms next to
Posted: Wed Jun 27, 2012 9:55 am
by KasperS
Hello
What is the best way to make sure there is no conduction gain/loss through the walls towards next to the room you want to simulate? I have tried both "adjacent building" and to set the temperature as ta, but doesnt give me a correct model.
Kasper
Re: Same temperature in rooms next to
Posted: Fri Jul 06, 2012 9:11 am
by bootsam
I draw a dummy room on all 3 sides and above and below set to same spec as the room i am modelling. I havent found any other way. I too am unsure about using the Adjacency and setting the temp as Ive done both and got different answers. A simple no heat flow button would be nice.
Re: Same temperature in rooms next to
Posted: Fri Jul 06, 2012 12:48 pm
by PCully
"Adjacent building" should give an adiabatic condition at the surface.
The unexpected results you saw were possibly related to heat loss into the wall though? Just a guess I'm not too sure really
Phil
Re: Same temperature in rooms next to
Posted: Mon Jan 13, 2014 3:39 am
by iwmech
Hello,
Regarding rooms marked as "Adjacent Building", I tested the adiabatic condition by modelling a room completely surrounded (all sides, above and below) by "adjacent buildings". Applying internal gains, I got non-zero conduction gains which implies that "Adjacent building" does not give an adiabatic condition.
The HVAC profile has been set such that it turns off between the hours of 9am and turns back on at 4pm during which the heat loss via conduction drops significantly.
I realise you said you weren't too sure about this Phil, but have you become aware of anything regarding the adiabatic condition of adjacent buildings or which might be able to explain the sudden conduction drop during HVAC off hours since?
Thank you.
Re: Same temperature in rooms next to
Posted: Mon Jan 13, 2014 2:59 pm
by Complex Potential
If you are refering to internal conduction gains then you need to remember that thermal mass and lag also contribute to that variable.
So... if you have a room surrounded on all sides by adiabatic conditions you will still see internal conduction gains/losses in the form of heat that is being absorbed/re-radiated by the fabric of the ceiling and internal walls (this effect is magnified if you have heavyweight constructions and exposed mass). Normally you will see a heat loss during the day as the fabric absorbs part of the internal gains and then you will see a heat gain at night as that warm fabric loses its heat back into the room.
That is my understanding.
CP