Title |
Heating Load Reduction by Energy Retrofit in an Old Residential Building |
Authors |
Cheong Chang-Heon ; Kim Tae-Yeon ; Leigh Seung-Bok |
Keywords |
Heating Load ; Energy ; Retrofit ; Apartment |
Abstract |
Energy retrofit of old residential building is very important, because old residential buildings take large amount in total residential building stock. Consequently, identifying the energy reduction effect of each building component's improvement should be performed. In this study, four major factors those affect the heating load significantly such as balcony thermal bridge, wall insulation, air-tightness and window property were considered. At first, the simulation condition and several variables such as U-factors of wall and window, linear thermal transmittance, air-tightness and infiltration are examined and simulation cases were established. Heating load of each case is verified by PHPP(Passive house Planning Package 2007). Simulation results show that removing balcony thermal bridge reduces heating load by 5.7%. Partial external insulation allowing thermal bridge does not reduce heating load much. Wall insulation reinforced to around 1.22~1.32 W/㎡K results in heating load reduction by 30.2~35.7%. Air-tightness enhancement to the passive house guideline reduces heating load by 22%. Mandatory additional ventilation rate of 0.7 ACH by retrofit increases heating load by 8.9%. However, the heating load reduction efficiency increases to 29.8% by adopting heat recovery ventilation system. Strengthening U-factor of window system to 0.8 W/㎡K diminishes heating load by 34.6%. Heating load of holistic model adopting most efficient components was 7 kWh/㎡a which meets the requirement of passive house standard in EU. |