What feature is commonly included in the design of corner strainers for roof drains?

The inclusion of increased open area is a significant feature in the design of corner strainers for roof drains. This design element is crucial because it allows for improved water drainage during rainfall or melting snow, effectively minimizing the chances of water accumulation on the roof. By maximizing the open area, the strainer can handle larger volumes of water, which is vital in ensuring that the drainage system functions efficiently under varied weather conditions.

Additionally, a larger open area helps reduce the risk of clogging, as debris can flow through more freely compared to a strainer with a smaller opening. This is particularly important in corner drains, which may be more susceptible to the collection of debris and other materials. Hence, the design optimally balances structural considerations with the need for effective drainage, making increased open area a key feature.

The other potential design aspects such as low profile, extended height, or built-in filters, while they may be relevant in certain contexts, do not address the primary function of ensuring efficient water flow and debris management as effectively as increased open area.