HVAC Operation Schemes and Commissioning Process Resolving Stack Effect Problem and Adjusting According to Changes in the Environment: A Case Study in High-Rise Building in South Korea

Abstract

Various problems often arise in high-rise buildings during the winter months due to the stack effect. In this study, the high-rise building of interest, located in South Korea, was experiencing constant loud noises in the winter due to the stack effect. Thus, we created a noise level reduction plan by creating a method for pressurizing the high-rise zones of the building according to outdoor conditions. To discover the appropriate pressurization operating modes, we applied a two-year commissioning process to the 50-story building of interest. The 1st- and 47th-floor elevator halls were identified to have the highest noise levels of all other floors. Prior to applying the reduction plan, the maximum noise level on the first floor with the HVAC system turned off was 85 dB(A) and with the HVAC system turned on it was 70 dB(A). Both values exceeded the criteria of 57 dB(A) for a lobby space of a commercial building. In the case of the 47th floor, the maximum noise level with the HVAC system turned off was 58.7 dB(A) and with the HVAC system turned off was 56.0 dB(A), despite the latter having increased airtightness performance and applying preliminary pressurization (i.e., HVAC operation mode 2). These values exceeded the criteria of 48 dB(A) for an elevator hall in a commercial building. Following this initial data, we determined to pressurize the high/mid-rise zones of the building according to the outdoor air temperature and wind velocity conditions, which we categorized into four types (i.e., HVAC operation mode 4). To this effect, the first-floor elevator hall’s maximum noise level was 56.6 dB(A), meeting the criteria, and the 47th-floor elevator hall’s maximum noise level was 49.5 dB(A), still exceeding the criteria but by an insignificant amount. Although the HVAC pressurization operation we utilized resulted in favorable results for the target building A, it may not be as effective in other new high-rise buildings, creating changes to the indoor air environment or to the energy costs in maintaining a building. However, for the purposes of resolving the stack effect, we believe that the commissioning process we took to optimize the HVAC operation that is presented here can be applied to other new and existing high-rise commercial buildings.

Combined Effects of Thermal Buoyancy, Wind Action, and State of the First-Floor Lobby Entrance on the Pressure Difference in a High-Rise Building

“…However, such methods have an inherent defect that only the improved positions will be ameliorated and the contribution to the problem mitigation of the overall building is minor, and they may even transfer the pressure difference from one place to another; e.g., applying partitions and revolving doors is effective for pressure mitigation on the target floor with entrances (e.g., first floor), but may increase the pressure difference on other elevator doors. The global method refers to overall improvements of a building, including improving the overall airtightness of the envelope [20], setting vertical segmentation of shafts [26], and using existing HVAC systems [11,27] or elevator cooling systems [28]. However, implementing global methods is quite challenging and expensive, and therefore, is rarely adopted in practice.…”

Field Study on Impact of Mechanical Pressurization on Pressure Distribution in High-Rise Buildings

“…In addition, they also put forward various operation modes for the HVAC systems to solve the unpleasant noises due to the stack effect. Even though the mode of pressurizing the high-rise zone of the building based on the outdoor air temperature and wind velocity effectively reduced the noise level, the indoor environment of the high-rise zone changed significantly [17]. However, there are limitations to these methods, such as the energy loss and potential discomfort caused by cold drafts entering from the shafts into indoor spaces [18].…”