Facade refurbishment for energy saving in tube houses a case study in Hanoi, Vietnam

This paper investigated the energy upgrade potentials of different facade refurbishment options in tube houses of Vietnam. A calibrated Design Builder model was created to simulate energy performance of different cases. Vietnamese technical regulation of energy efficiency building and Dutch standards were the two main guidelines for selection of refurbishing measures. The simulation results showed that applying Vietnamese technical regulation can save up to 9% of energy for heating and cooling. More interestingly, highly insulated facade that followed Dutch standards led to much more favourable results of 21% reduction in air conditioner consumption. It is worth to note that such improvement was by far only achieved with a night-time operation of air-conditioner, as how the system was working in the reference house. Shading devices were also tested on a southwest facade window. Horizontal overhang had very limited benefit of less than 6% reduction in cooling energy. An external blind could save up to 12.6% of cooling energy. However, as all three shading types had a negative effect in heating season, the maximum annual saving was only 7%.