Abstract

Guaranteeing high indoor air quality and high degree of usersatisfaction at the same time is one of the challenges when improving the energy efficiency, namely the energy consumption, of a building. Current non-residential buildings mainly use mechanical ventilation systems to ensure high air quality. Natural ventilation can be an alternative regarding to lower maintenance costs and the psychological feeling of fresh air. Present natural ventilated buildings pose the risk of higher energy demand and less indoor air quality due to user’s behaviour. Controlled natural ventilation based on indoor CO₂ concentration and room air temperature is needed. However, the energy efficiency of a control strategy highly depends on climate zone and control parameters. This paper aims to explore the impact of different control strategies on the energy efficiency of an operable louver window. The analyses are done for yearly results and then for each month individual to clarify the effect of monthly varying control strategies. For the analysis EnergyPlus as a building energy simulation tool and for the natural ventilation in specific the EnergyPlus Design Flow Rate method is used. In the simulation four window opening strategies based on CO₂ concentration and one simple intake/exhaust mechanical ventilation system were tested in Mediterranean, subtropical and moderate climate zone. The highest impact on energy efficiency and thermal comfort was seen at the cold months in the moderate climate. Long window opening strategies cannot be implemented because of a high thermal discomfort. In the hot months in the Mediterranean and subtropical climate an impact of ventilation strategies are seen as well. Only at moderate conditions no major differences in the natural ventilation strategies were observed. When comparing the natural ventilation conditions to mechanical ventilation major differences were found. In almost all climate conditions natural ventilation outperformed the mechanical ventilation. Only in winter months in the moderate climate mechanical ventilation outperforms natural ventilation.

摘要

同时保证高室内空气质量和高用户满意度是提高建筑物能效即能耗的挑战之一。目前的非住宅建筑主要采用机械通风系统来保证高空气质量。自然通风可以成为降低维护成本和新鲜空气心理感觉的替代方案。由于用户的行为，目前的自然通风建筑存在更高的能源需求和更低的室内空气质量的风险。基于室内 CO _{2 的}受控自然通风需要浓度和室温。然而，控制策略的能源效率在很大程度上取决于气候区和控制参数。本文旨在探讨不同控制策略对可操作百叶窗能效的影响。对年度结果进行分析，然后对每个月的个人进行分析，以阐明每月不同控制策略的效果。对于作为建筑能源模拟工具的EnergyPlus分析和特定的自然通风，使用EnergyPlus 设计流量方法。在模拟中基于 CO _{2 的}四种开窗策略在地中海、亚热带和温和气候区测试了浓度和一个简单的进气/排气机械通风系统。在温和气候下的寒冷月份，对能源效率和热舒适性的影响最大。由于高热不适感，无法实施长时间开窗策略。在地中海和亚热带气候的炎热月份，也可以看到通风策略的影响。只有在中等条件下，才观察到自然通风策略没有重大差异。在比较自然通风条件与机械通风条件时，发现了主要差异。在几乎所有气候条件下，自然通风都优于机械通风。