In cooling seasons users have to block direct solar radiation by closing solar shadings to avoid internal overheating. In others seasons solar shadings should be opened to take advantage of natural light and, in heating seasons also of solar radiation to increase internal thermal load.
Shading windows can block up to 90% of heat generated by direct sun.
Reduce internal summer temperatures
Reduce the use of cooling and heating systems
The initial investment is zero, although it is convenient to train and inform properly users on these issues. It reduces the costs associated to HVAC systems.
References and best practices
Impact of external shading devices on thermal and daylighting performance of offices in hot climate regions: sciencedirect