Building Envelope Energy Performance

Transcription

1 Building Envelope Energy Performance Gustav Nordström PhD Student Luleå University of Technology Sweden Nordic Symposium on Energy Efficiency in Buildings Oulu, Finland, 27 September, 23 Measuring and comparing building energy performance. The theme has been to measure with: few and small installations, if possible use already installed meters The energy signature theory has been used to evaluate the results of this approach First check how the method works on houses with district heating and no other heat source and no forced ventilation systems Then check houses with mechanically forced ventilation The heat loss factor used to calculate Effective U-value

2 This work is basis for three papers First and second paper compare the Effective U-value to Building regulations and theoretical transmission losses Third paper compare forced ventilated houses with naturally ventilated houses. Journal paper is a work in progress. Measurement equipment District heating measured on the billing meter Electricity measured on the billing meter Temperature sensors installed Base station sample data with a minute interval and upload on centralized server 2

3 Power Power W District heating measurement Time Time (hours) 5 Energy signature method P W K(T i T e ) K W U W m 2 T = T i T e 6 3

4 Houses Year of constructi on Frame/ facade Brick Envelo pe area [m²] Stori es Theoretic al U- value [W/m²K] HRV- System Inhabitants 298,53 None 4 (2 adults) 454.5,33 None 2 (2 adults, ,3 Preheated air intake in kitchen fan 4 (2 adults, 2 26a 26b ,3 None 523,3 None 596.5,35 None Systemair VM2 HERU 9 T EC 4 (2 adults, 2 3 (2 adults, 4 (2 adults, 2 6 (2 adults, 4 4 (2 adults, 2 Measurement 22 Heating for year 22 9 y = -2,7x + 2 8,93 R² =,87 y = -9,22x ,5 R² =,95 Above 7 C Below 7 C Outdoor Temperature 8 4

5 Measurement seasons Heating spearated in to seasons Nov 2 -Oct 22 9 y = -83,234x + 78, R² =,877 May-Aug y = -8,35x R² =,97 y = -44,7x , R² =,8924 Nov-Feb Mar-Apr and Sep- Oct Outdoor Temperature dependency District heating 967 P DH (W) 967 P DHW (W) 9 9 y = -72,93x ,45 R² =,96 y = -3,32x + 279,4 R² =,

6 967 dependency Electricity and Heat loss factor 967 P E (W) 967 P H (W) 9 9 y = 7,8x - 94,8 R² =,94 y = -2,75x + 534,43 R² =, Temperature difference 987 dependency District Heating 987 P DH (W) 987 P DHW (W) 9 9 y = -34,92x + 673,2 R² =,82 y = -5,8x + 86,23 R² =, Outdoor Temperature ( C) Outdoor Temperature ( C) 2 6

7 987 dependency Electricity y = -45,67x + 238,47 R² =, P E (W) Outdoor Temperature ( C) 987 P E selected observations (W) y = -29,46x + 274,68 R² =, Outdoor Temperature ( C) Heat loss factor P H (W) y = 39,85x - 66,4 R² =, P H +P E (W) y = 84,43x - 42,4 R² =, Temperature Difference( C) Temperature Difference( C) 4 7

8 22 dependency District heating 22 P DHW (W) 22 P DH (W) 9 9 y = -65,55x + 72,46 R² =,8 y = -57,58x + 47,28 R² =, dependency Electricity and Heat loss factor 22 P E (W) 22 P H (W) 9 9 y =,25x - 452,32 R² =,35 y = -,3x + 943,6 R² =, Temperature difference 6 8

9 22 Heat loss factor 9 22 P H Selected Observations (W) y = 27,78x - 65,63 R² =, Temperature difference 7 Effective U-values Year of construction Transition U- value [W/m²K] K [W/K] Effective U- value (E Eff ) [W/m²K] 967,53 7,57 983,33 6*,26 987,3 84,38,3 53*,29 26a,3 32,25 26b,35 89, **, **,27 *Observations only from Nov-Feb /2 **Observations only from Nov-Feb 2/3 8 9

10 Concluding remarks We see that houses without forced ventilation has lower standard deviation than houses with. In addition hoses with fire stove have a larger standard deviation We also see that houses without forced ventilation tend to have lower effective U-value than calculated transmission losses suggest. Finally we believe that energy signature is good method to in an easy manner evaluate the performance of the building envelope. 9 Acknowledgments Financial support from the European regional development fund via the Interreg IVA North program is gratefully acknowledged. 2