Prevent Air Conditioning & Heat losses.
Prevents Insects and dust.
Maintain the the ambience of the environment.
Help in seperating two environments
Cooler / Freezer applications
The physical dimensions of the opening
Type of Opening – customer entry, service entry, dock door etc. (Residential, Commercial, Industrial etc.)
Prevailing winds and temperatures on outside openings.
The existence of any drafts due to pressure differences at the opening.