Energy renovation and healthy indoor environment in green buildings -Impact of dynamic shading and demand controlled ventilation on occupant health and comfort
Typ
Examensarbete för masterexamen
Program
Publicerad
2021
Författare
Bergström, Gunnar
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
A number of measures exist that can help to reduce the energy use of existing buildings, such as
demand controlled ventilation and dynamic shading. However, when they are implemented they
can also have an on impact the comfort and health of the building’s occupants. Discomfort in the
domains of thermal comfort, visual comfort and air quality can cause health issues ranging from
mild to severe and can significantly impact the performance of office workers with resulting
economical losses for employers. Increased awareness of occupant comfort in the design and
operation of office buildings can have both health-related and economical benefits.
A case study was carried out for a newly renovated office building where occupants have reported
some amount of thermal and visual discomfort. A possible explanation for the discomfort was
found in imbalances in the implementation and operation of the demand controlled ventilation
and dynamic shading systems. The case study building, which has been awarded a Miljöbyggnad
Silver certification, was studied in detail and it was found that thermal discomfort was likely
to arise due to the intricate interplay between heat added by the sun and the occupants and
heat taken away by the ventilation air flow. Since occupants are also a source of air pollution,
ventilation and shading needs to be carefully balanced to ensure that thermal and visual comfort
and acceptable air quality are maintained under all circumstances. The geometry of the shading
device and the colour of the shading fabric can also be configured to further improve visual
comfort and thermal performance.
In general it was found that occupant comfort can be improved by detailed and holistic study of
the building, how it behaves and how conditions vary in both space and time. The more time
and effort is spent on identifying issues and customizing the building, the better the outcome
for occupant comfort. However, increased customization means increased complexity and cost,
making it more difficult to successfully implement the intended design. If significant causes
of occupant discomfort are identified more clearly and methods are developed to address them
in a streamlined and efficient way, it is more likely that the health, comfort and well-being of
occupants will be put into focus when designing office buildings.
Beskrivning
Ämne/nyckelord
Demand controlled ventilation, dynamic shading, indoor environmental quality, thermal comfort, visual comfort, air quality, energy efficiency, building renovation, health