In 2017 the Danish Building and Property Agency started a project titled “Avoiding energy waste in ventilation systems” by tracking the actual energy use in a sample of their 4 million m2 portfolio of buildings through on-line energy management tools. The project is not complete, but the key preliminary findings described in this paper are:
- The energy consumption of ventilation systems is a much higher proportion of the total energy consumption of the buildings than expected.
- The ventilation system components are generally well maintained, but the ventilation systems as a whole are not well maintained, which results in poor indoor climates in buildings, despite the high energy costs.
- Although a component was possibly checked, it was found that an important distinction between component function and component quality caused operational problems if the component was not calibrated, or its real function was not tested.
- Original design or installation mistakes not discovered at the time, often complicated by changes to the systems over time, led to additional ad-hoc attempts at system repairs over many years, which often did not address or correct the original faults.
- The control systems are extensive and have developed - or mutated - over many years into webs of complexity that are difficult to analyse, understand or operate effectively, so that user complaints often lead to systems being “adjusted” inappropriately.
- A growing tendency is the apparent abandonment of faith in existing ventilation systems and investment in several small decentral cooling or ventilation systems, often installed in the same areas served by the central ventilation systems, thus adding to the energy burden and also adding to the complexity of the indoor climate control systems.
- Re-creating ventilation system documentation and design information combined with installing indoor climate data loggers allowed analysis of system performance, and thus revealed possibilities for simple indoor climate improvement as well as energy savings.
- The overall results appear to confirm that the old saying “Keep it simple” is still true, and that the use of intelligent user-friendly data monitoring tools should be combined with simpler user-friendly control tools so that Facility managers and other operators can achieve a better correlation between energy use and indoor climate.
- The overall conclusion of this study is that our ventilation industry is still too focused on theoretical project design and construction delivery, with an overall belief in complex controls. Combined with a lack of attention to durability and operational performance, most ventilation systems degenerate within a short period of time into systems with high energy costs providing low indoor climatic quality.
- The overall recommendation of this article is that our ventilation industry reduces its attachment to traditional business goals of growth and turnover and instead focuses on quality of the delivered product through simplification and durability.