simulation-based assessment of energy and environmental performance of office buildings in lebanon...

Simulation-based assessment of energy and environmental

performance of office buildings in Lebanon

Z. Alameddine, K. Orehounig, A. Mahdavi,

Department of Building Physics and Building EcologyVienna University of Technology, Vienna, Austria

Introduction

Lebanon has a moderate Mediterranean Climate . In coastal areas, winters are generally cool and rainy whilst summers are warm. Lebanon has no fossil fuel resources. 98% of all energy needs are met with imports of petroleum products.

Method

Method

Scenarios

Insulation

Glazing

Shading

Lighting

Ventilation

Mass

1 Ib Gb S0 L1 V1 Mb

2 Ib Gb S0 L2 V1 Mb

3 Ib Gb S0 L1 V2 Mb

4 Ib Gb S0 L1 V3 Mb

5 Ib Gb Si,a L1 V1 Mb

6 Ib Gb Se,a L1 V1 Mb

7 Ib Gb Sf L1 V1 Mb

8 I7 Gb S0 L1 V1 Mb

9 Ib Gb S0 L1 V1 Mnc

10 Ib G0,22 S0 L1 V1 Mb

11 Ib G0,14 S0 L1 V1 Mb

12 I7 Gb S0 L1 V3 Mb

13 Ib Gb S0 L1 V3 Mnc

14 Ib Gb Si,a L1 V1 Mb

15 Ib Gb Se,a L3 V1 Mb

16 Ib Gb Se,a L3 V2 Mb

17 Ib Gb Se,a L3 V3 Mb

18 Ib Gb Se,a L3 V4 Mb

Parameters Base Case Modified Case

Insulation 1,6…3,2 0,4…0,5( with Insulation)Glazing 2,8…5,7 1,7Shading types

No shades

Internal External Fixed

Shading schedules -

Dynamic Fixed

Lighting - Efficient LightingVentilation - Night time ventilation

Method

Heating load (kWh.m-2.a-1)

External Insulation

External shading

External shading and high night-time ventilation

Selected Results

Latent cooling load (kWh.m-2.a-1)

Sensible cooling load (kWh.m-2.a-1)

Externalinsulation

Better glazing

External insulation and ventilation

External shading ,high night-time ventilation and daylight

Night ventilation

Selected Results

Sensible cooling load reduction (in percentage of the base case)

Night ventilation

External shading

External insulation

Better glazing

Combinations

Internal mass and night-time ventilation

Selected Results

Mean overheating (see Table 11 for assumptions regarding θr)

Mean overheating (θr=26oC)

Externalinsulation

Better glazing

External insulation and ventilation

External shading ,high night-time ventilation and daylight

Night ventilation

Selected Results

Mean overheating reduction (in percentage of the base case) for θ r=26oC

Night ventilation

External shading

External insulation

Better glazing

Combinations

Internal mass and night-time ventilation

Selected Results

Heating Loads are minimal and can be eliminated by implementing some measures like external insulations , better glazing.

Latent cooling load variations in different scenarios are rather small (4-6 kWh.m-2 .a-1); increase is due to higher ventilations input.

Sensible cooling loads are significant.

60% Less Cooling loads can be achieved by combining external shading, high night time ventilations ,efficient lightings, and using daylight.

Overheating reduction potential is likewise substantial and can reach up to 68% .

Conclusion

Thank you

Z. Alameddine, K. Orehounig, A. Mahdavi,

Department of Building Physics and Building EcologyVienna University of Technology, Vienna, Austria