Marche Polytechnic University Department of Architecture, Construction and Structures Technical Architecture Section   The...
Kyoto Protocol - 2005 Passive Cooling Systems   To reduce at least 5% of the global CO2  emissions between 2008-2012  impo...
Dlgs. 311/2006 winter Italy  introduction of  high requirements  on: thermal insulation   of buildings  (U = transmittance...
national guidelines   SUMMER replace Ms limit >= 230 kg/m2 with the: Yie = U x fd  <= 0,12 W/m2K Periodic Thermal Transmit...
Problem of periodic thermal transmittance   Yie = U x fd  Possibility of super insulated and low mass building walls Yie <...
opportunity:  Consider the Internal Periodical Heat Capacity (Cip) kJ/m2K Importance of indoor thermal comfort and interna...
Taking a REAL CASE STUDY 1) MONITORING 2) SIMULATION AND CALIBRATION OF THE ANALYTICAL MODEL WITH THE MONITORING DATA <ul>...
Different Typologies studied walls: 5 ideal walls in order to respect periodic and stationary thermal trasmittance limits ...
RESULTS: <ul><li>U strongly conditions the thermal behavior of external walls </li></ul><ul><li>External walls characteriz...
For the same value of Yie there is no difference between the 5 typologies of the wall Summer period (without internal load...
<ul><li>If we consider the impact of: </li></ul><ul><li>COMFORT   (Surface temp., Operative temp., radiant asymmetry) </li...
Roof impact on comfort Enviromental internal conditions are affected by their thermal insulation position
Internal periodical heat capacity  (Cip): - Cip is the real wall capability to store the heat The value Cip, calculated ac...
During the summer, if we have elevated values of internal loads, it will be to more importante to fix a big value of the C...
We believe it is suitable to fix an inferior limit value of Cip  in order to: <ul><li>Support walls with sufficient inerti...
This could be the parameter verification to be attached to the periodic thermal transmittance   Control of comfort and con...
Thank You for your Care Ing. Andrea Ursini Casalena http://www.mygreenbuildings.org Marche Polytechnic University http://w...
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Strategies For Sustainable Building Envelopes Ventilation And Inertial Mass The Effectiveness Of A Good Thermal Inertia Of Building Walls

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In this slide easily explained as the thermal inertia of an internal wall can be effective in increasing the thermal comfort in buildings, as well as an aid to reducing the cooling load during summer.

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Strategies For Sustainable Building Envelopes Ventilation And Inertial Mass The Effectiveness Of A Good Thermal Inertia Of Building Walls

  1. 1. Marche Polytechnic University Department of Architecture, Construction and Structures Technical Architecture Section The Effectiveness of a Good Thermal Inertia of Building Walls Strategies for Sustainable Building Envelopes: Ventilation and Inertial Mass 10 February 2009 Ing. Andrea Ursini Casalena http://www.mygreenbuildings.org
  2. 2. Kyoto Protocol - 2005 Passive Cooling Systems To reduce at least 5% of the global CO2 emissions between 2008-2012 importance of the climatic characteristics of the site DIRECTIVE 2002/91/CE on the energy performance of buildings European Union Comfort problems Air conditioning priority of reduce obligation to save energy
  3. 3. Dlgs. 311/2006 winter Italy introduction of high requirements on: thermal insulation of buildings (U = transmittance W/m2K) summer It receives only a share of the Directive 2002/91/CE superficial approach to the problem of summer comfort and thermal inertia of building envelope WINTER ENERGY SAVING and the needs of energy for winter heating (Epi =kWh/m2year) but… It does not consider the effects of internal heat loads (people, diffuse radiation, appliances…)
  4. 4. national guidelines SUMMER replace Ms limit >= 230 kg/m2 with the: Yie = U x fd <= 0,12 W/m2K Periodic Thermal Transmittance Direct radiation Air temperature Yie UNI EN ISO 13786:2008 ? internal heat loads PROBLEM:
  5. 5. Problem of periodic thermal transmittance Yie = U x fd Possibility of super insulated and low mass building walls Yie <= 0,12 W/m2K 0,12 = 1 x 0,12 0,12 = 0,12 x 1 U fd Yie U fd Yie High mass Low mass = ACCORDING TO GUIDELINES
  6. 6. opportunity: Consider the Internal Periodical Heat Capacity (Cip) kJ/m2K Importance of indoor thermal comfort and internal loads in summer Results of our studies: 1) Periodic Thermal Trasmittance is effective in limiting the external loads 2) Periodic Thermal Trasmittance doesn’t ensure indoor thermal comfort with the internal thermal loads Internal loads Diffuse radiation
  7. 7. Taking a REAL CASE STUDY 1) MONITORING 2) SIMULATION AND CALIBRATION OF THE ANALYTICAL MODEL WITH THE MONITORING DATA <ul><li>weather conditions (Palermo, Ancona, Cuneo) </li></ul><ul><li>destinazione d’uso (scuola, residenza) </li></ul><ul><li>internal thermal loads </li></ul><ul><li>building enevelope </li></ul>3) PARAMETRIC ANALYSIS FOR: SCHOOL Indoor conditions weather conditions Surface temperature
  8. 8. Different Typologies studied walls: 5 ideal walls in order to respect periodic and stationary thermal trasmittance limits for instance: For the same value of Yie = 0,10 W/m2K, we have difference thicknesses of inertial mass and thermal insulation U < 0,4 W/m2K (Ancona) Yie < 0,12 W/m2K
  9. 9. RESULTS: <ul><li>U strongly conditions the thermal behavior of external walls </li></ul><ul><li>External walls characterized by low stationary transmittance have superior behaviour </li></ul>Winter period <ul><li>limiting the periodic thermal trasmittance allows to: </li></ul><ul><li>bound the external loads </li></ul><ul><li>contain summer and winter energy use </li></ul>U=0,39W/m2K U=0,26 U=0,17 U=0,15 U=0,13 N
  10. 10. For the same value of Yie there is no difference between the 5 typologies of the wall Summer period (without internal loads, ideal conditions) N
  11. 11. <ul><li>If we consider the impact of: </li></ul><ul><li>COMFORT (Surface temp., Operative temp., radiant asymmetry) </li></ul><ul><li>INTERNAL LOADS (people, appliances, diffuse radiation) </li></ul>Low value of thermal inertia = temperature with raised swings = low comfort Summer period (with internal loads, real conditions, school) It is need to Internal Thermal Inertia N
  12. 12. Roof impact on comfort Enviromental internal conditions are affected by their thermal insulation position
  13. 13. Internal periodical heat capacity (Cip): - Cip is the real wall capability to store the heat The value Cip, calculated according to UNI EN ISO 13786:2008, describes the building envelope behavior. It considers the deep of penetration of thermal wave - A Big value of Cip helps in reducing the superficial walls temperatures
  14. 14. During the summer, if we have elevated values of internal loads, it will be to more importante to fix a big value of the Cip Internal periodical heat capacity (Cip): To obtain an optimal level of comfort, the walls have to guarantee a big value of Cip
  15. 15. We believe it is suitable to fix an inferior limit value of Cip in order to: <ul><li>Support walls with sufficient inertial mass by internal side </li></ul><ul><li>=> they contribute in the thermal store and in improving the indoor comfort </li></ul><ul><li>thwart building envelopes characterized by internal insulation or without inertial mass </li></ul><ul><li>=> they do not contribute in the thermal store </li></ul>
  16. 16. This could be the parameter verification to be attached to the periodic thermal transmittance Control of comfort and consumption in the summer and half seasons Direct radiation Air temperature Diffuse radiation Cip excellent indication of the goodness of the wall Yie
  17. 17. Thank You for your Care Ing. Andrea Ursini Casalena http://www.mygreenbuildings.org Marche Polytechnic University http://www.univpm.it

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