Things To Consider For Exterior Louvers
Louvers provide ventilation allowing air to pass through a window while at the same time keeping unwanted elements such as dirt, water, and other debris out. Exterior architectural louvers feature a number of fixed or operable blades that are mounted in a frame. There are many factors to consider when dicing upon exterior louver.
Factors
There are a variety of factors that must be taken into consideration when deciding on which louvers to install. Factors such as free area, water penetration, and air resistance must be properly determined to allow for the best louver solution.
Free Area
To determine the free area, it’s important to take the total open area of the louver. This is done by subtraction all the potential obstructions such as blades and the actual frame and then diving the overall wall opening. This then allows for a comparison of the louvered opening as opposed to an unobstructed opening. The common range for louver free areas is about 35% to 60% of the wall opening. Having a high percentage of free area is very beneficial. This will allow for more air to enter a smaller wall opening, this will therefore, reduce the cost of the wall opening as well as the louver.
Obstruction
Obstruction is important as it prevents water from entering through the louver. A wholly obstructed opening will not allow any amount of water to enter. A fully non obstructed opening will let water enter at an unimpeded rate. However, a properly designed louver will all for an optimized free area while at the same time allowing for minimal water entry.
Water Penetration
Water penetration is considered when figuring the velocity of air intake. The first point of water penetration is the exact point in which the louver will let water enter. By figuring the threshold measurement of the air intake velocity the water penetration point will be determined. This calculation will allow for the best louver installation.
Resistance to Air Flow
An obstruction found int eh air stream will cause a resistance, or pressure loss. These obstructions can include building structure, filters, coils, ductwork, and louvers. The actual air flow resistance is determined by measuring the air flow running through the louver in comparison to the pressure difference found at any given free area velocity.
Blade Shape
Louvers will create a resistance to air flow. This is because they cause an obstruction. The frame of the exterior sun control system as well as the shape of the blade determines the resistance of the air flow. Blades that are of lover angles will have a more aerodynamic shape that allows for less resistance. In order to fully figure the resistance to airflow the free velocity allowed by the louver must be determined. It is very important to figure out the resistance because this will help maximize air flow.