RE: [EnergyPlus_Support] thermal mass versus insulation

[<josep.sole@xxxxxxxxxxx>]

Energy balance (or comfort temperature) is a resultant from many items:

Thermal transmission on opaque constructions

Thermal transmission on windows

Ventilation / Infiltration

Solar gains

Internal gains

Internal heat storage

Internal heat release

..........

 

In each time step the relative amount is different and it's influence (interrelation) is significantly different (in some cases contradictory).

 

On southern Europe Zones my opinion is:

Heat storage can be used on winter to heat (releasing heat) during night (if some excess exists during day) , during this time energy can be reduced without unconfort risk (this situation is only interesting if  building is used at nigh) but in this case it's necessary start heating earlyer at mooning because part of energy is used to heat internal mass. Depending climatic zone, use profile, thermal envelope characteristics, building orientation,... it will be more or less interesting to increase / decrease internal thermal mass.

 

On summer heat storage can be used to delayed the internal temperature increasing (part of the solar and internal gains is used to store heat on internal mass) in this case it's necessary eliminate this excess of heat during night increasing night ventilation. Depending climatic zone, use profile, solar shadings, envelope characteristics, night ventilation,... will be more or less interesting to increase / decrease thermal mass.

 

But in any case differences are very small and is not the main point to improve for thermal comfort or energy savings (can be helpful to maximize other thermal strategy) 

 

It's very risky to extrapolate conclusions (between buildings, climatic zones, uses profile,...)  because there are to many factors interrelated between them.

 

Internal mass must be placed where it will be possible for the natural ventilation to interchange heat with storage mass. Usually façade is the worse place to put it.

 

 

Josep Sole

URSA Iberica Aislantes SA.

 

 

 

________________________________

De: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] En nombre de Drury.Crawley@xxxxxxxxxx
Enviado el: sábado, 16 de septiembre de 2006 23:13
Para: EnergyPlus_Support@xxxxxxxxxxxxxxx
Asunto: Re: [EnergyPlus_Support] thermal mass versus insulation

 


Mass helps if you allow the indoor temperature to swing. If you
hold it close to the same setpoint, it can increase energy.
I notice in my own house that the brick walls continue to bring
heat into the house during the summer long after the outside
temperature has dropped.

"Emanuele Naboni" 
<emanuele.naboni@gmail. To: EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com>  
com> cc: 
Sent by: Subject: [EnergyPlus_Support] thermal mass versus 
EnergyPlus_Support@yaho insulation 
ogroups.com 


09/15/2006 06:48 PM 
Please respond to 
EnergyPlus_Support 




Gents,

I am running a simulation to understand for a residential building located
in Milan if is better to have an envelope with thermal mass or a light wall
(similar to passive house wall). Both wall have the same K=0.4w/hm2 °C.

The light wall gives better Energy consuptions performance in winter
season, the thermal mass during the summer.
Is this a reasenable result?

Might it be that the thermal mass during the winter absorbe part of the
heat
from the HVAC?
Thanks in advance to anyone has experience on the field!

Emanuele Naboni

[Non-text portions of this message have been removed]

 



[Non-text portions of this message have been removed]



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