Architectural Louver Design and Specification

Louvers may be a requirement, but they don't have to drag down your designs. Learn to design and specify louvers for your architectural projects.

Louvers are an important part of your building. They protect ventilation points from water infiltration, but they can also help your designs. But how do you specify a louver? In this article, we will help you design and specify louvers for your project.

We will begin with the fun part: designing louvers. We have covered louver design quite a bit on the MCDLG Newsstand, so check out our informative blogs for more tips on crafting the perfect louver.

Design for Performance

Louvers are a series of metal blades, spaced out evenly inside of a frame. There is space between each blade to allow airflow through the louver. The blades are angled downward to deflect rain and other harmful elements. The slope of the blade also acts as a drain feature, so that deflected water falls out of the louver.

Certain louvers will have additional blade features, like catches, to capture rain carried in by gusts of wind. These features are difficult to see when viewing the louver from its face. Manufacturers will often provide a cut-away view of the louver, so you can see the blade profile. This will help you see the blade features.

Drain troughs collect rainwater along the face side of the blade, which is important during heavy rain. These troughs connect to channels in the louver’s jambs, which lead to the bottom of the louver. Drainable blades prevent water infiltration through drain cascades and backsplash.

Design for Aesthetics

Louver blades are an important design feature, but there are other design features to consider. Size and shape will be important considerations as well. You may need multiple louver panels to fill a large opening, or a circular shape frame to fit a circular opening. Any non-rectangular or non-square shape is considered a custom shape.

Note that AMCA ratings will not carry over to custom-shaped louvers.

For louvers with multiple panels, you will need to contend with mullions in your designs. A mullion is a line made when two louver panels meet. Do you want vertical lines between each louver panel, or do you want a more seamless look across the face of the louver? If you want fewer lines, look for louvers with the continuous line option. This hides the mullions behind the blades, which makes multiple louver panels appear as a single panel. 

Finishes add a touch of color to the louver, so that it can blend in or stand out on the façade. Manufacturers will provide a list of available colors and shades for each finish type. Read this article for the full details on finishes. Some manufacturers will also offer color-matching, where they can match the louver’s finish to the perfect color and shade.

At MCDLG, we provide color matching on our long-lasting power paints. Get the perfect shade and make it last.

Specifying Your Louvers – Part 1

With the louver designed, you will now need to specify the louver. As you know, specifications provide a list of components and materials used in the finished project. A louver specification ensures that the louvers are installed.

Louvers fall under CSI Division 08 for Openings. The full three-part division number is as follows:

• 08 Openings
• 91 Louvers
• 00 Louver type

The third number will change based on the specified louver:

• 13 Motorized Wall Louvers
• 16 Operable Wall Louvers
• 19 Fixed Louvers
• 26 Door Louvers

Fixed louvers are the most common type of louver. The term “fixed” refers to stationary blades, which are “fixed” in place. “Operable” louvers will have adjustable blades that can open and close when necessary. “Motorized” louvers are adjustable louvers with an actuator. Once you have the correct CSI division, you can begin specifying the louvers.

Specification documents start with general information about the louvers. Provide a list of product types included in this section, like severe weather louvers or drainable louvers. Then, list other CSI divisions that pertain to this section. For example, include 09 91 13 for Exterior Painting for louvers with a custom finish. If you plan to specify other louver types, add their CSI division numbers to this section as well.

Next, add any standards or guidelines to the References section. This includes standards for testing like AMCA 550 or AAMA 2605. For louvers, make sure you include AMCA Standard 501 and AMCA Standard 511. These are common standards that apply to most louvers used for ventilation.

If the louver will be used for hurricane protection, then include AMCA Standard 512 as well as AMCA Standard 540 and 550. The References section should include all the standards and guidelines relevant to the listed louvers.

The General section will also include areas for the following:

• Definitions: Define terms and phrases used throughout the document. You will need to define things like “free area” so that readers will understand.
• Submittals: List documentation that will be included with the specification document. Manufacturers will provide submittals that provide important information about each louver model.
• Quality Assurance: Provide qualifications for building and installing the louver. This can include things like the minimum required experience for building louvers. These qualifications ensure the louver is a quality build and will be properly installed.
• Delivery, Storage, Handling: Add guidelines for safely delivering louvers to the construction site. These can be general guidelines like “store in a cool, dry place before installation”.
  • Note: Include instructions on properly lifting the louver by its frame, and not by its blades. This is a common issue in the field that leads to damaged units. Louver blades are not designed to support the weight of the full assembly, especially with larger units. Whether lifting by hand or via forklift, installers should lift the louver by the frame.

• Sequencing and Scheduling: This area will be the same for most louvers. Explain that the louver should be sized to fit the opening or installation area. Make sure the dimensions are marked on the louver’s shop drawings. You should also explain when the louver should be delivered to the construction site.
• Project Conditions: Make a general statement about the conditions of the construction site during installation, such as temperature and humidity. These conditions should be within the manufacturer’s posted limits.
• Warranty: Include the warranty for the louver and the warranty for the louver’s finish. Louvers with powder-paint finishes will typically last 10 years or more.

Specifying Your Louvers – Part 2

The next part of the specification document will list the individual louvers. Start this section by listing the manufacturer’s information. If this is an open specification, then you may list multiple manufacturers as “acceptable manufacturers”. If there is only one manufacturer listed, then be sure to include their mailing address, phone number, and contact email. This will help readers contact the louver manufacturer, if they have any questions.

Then, list guidelines for louver design under the “General” area. This includes how the louver should be constructed by the manufacturer, as well as guidelines for the installation area. The louver, and the surrounding area, should be built for design wind loads.

After that, we list the louvers. Start with the type of louver, even if you only list one type in the document. Each type of louver should have its own subsection. This helps organize the information for each louver, especially if you have multiple louver types.

With the subsection established, we will now list the details of each louver:

• Product: List the name of the product and the manufacturer. For example, the AS3D99VS by Airline Louvers.
• Application: Explain what the louver will do at the installation site. If the louver is there to meet a requirement, be sure to list those requirements in this section.
• Louver Depth: How deep is the louver frame?
• Blade Profile: Explain the blade’s shape. For example, use “upward chevron curve” for chevron blades.
• Blade Spacing: List the blade spacing or the amount of free space between each blade. This will be listed on the louver’s submittal.
• Blade Angle: Provide the blade angle, if the louver has stationary blades. For adjustable blades, provide the range of motion from closed to full open; “Full closure to 45 degrees”.
• Free Area: List the amount of total free space across the full louver in square feet or similar metric. Manufacturers will provide a free area chart to help determine this number.
• Pressure Drop*: This is a performance metric found on the louver’s submittal. Check for the AMCA Certified Ratings Seal for Air Performance before adding this value to the specification.
• Point of Beginning Water Penetration*: This is a performance metric found on the louver’s submittal. Check for the AMCA Certified Ratings Seal for Water Penetration before adding this value to the specification.
• Frame and Blade Nominal Thickness: List the thickness of material used for each component of the louver. If they differ in thickness, list them separately.

*Leave these sections out if the louver does not have an accompanying certified ratings seal.

Add any other relevant performance data or ratings to this subsection, like wind driven rain performance and AMCA certified ratings seals.

The next subsection will include details on fabricating the louver. It will include constructing the louver and applying finishes. It’s important to get the details right in a specification. Manufacturers like Airline Louvers can help you fill out this section, if you’re not sure what to write here.

Specifying Your Louvers – Part 3

The final part of your specification document will be “Execution”. The subsections of this part will include examining the louver, preparing it for installation, installing it at the installation site, and testing any moving parts to ensure unhindered motion.

There will also be a section for proper cleaning and maintenance. You can refer to the manufacturer’s installation instructions for this section, as well as their guidelines for operations and maintenance (O&M).

Specification documents can be a hassle, but it’s important to have these details on paper. If you’re not sure about your specs, then check with the louver manufacturer.

Manufacturers often provide specification templates to help ease the pain of spec writing. At MCDLG, we can help review your specifications and offer advice on what to add next. Your designs are important. Make sure your specifications match. Specs are the plan to your vision.