Titanium Dioxide Coatings
Titanium dioxide is a widely used white compound known for its strong ultraviolet (UV) light-absorbing capabilities and its resistance to discoloration under UV light. In powder form, titanium dioxide is an effective pigment that provides whiteness and opacity to products such as paints, coatings, plastics, papers, inks, sunscreen, medicines, and toothpaste, as well as quick-setting concrete and tile grout. Titanium dioxide naturally attacks organic pigments in paint. An innovative titanium dioxide coil-coating process protects paint and enhances paint finish performance, while providing environmental and cleaning benefits. When combined with aluminum, the result is a process that could not occur with either material alone.

Environmental Benefits

Titanium dioxide has two unique effects. If exposed to sunlight, titanium dioxide acts as a catalyst to break down organic matter, while also creating a superhydrophilic (water-loving) surface. When a titanium dioxide coating is applied to the pre-painted aluminum surface of a metal composite panel, the result is a coil-coated aluminum architectural panel that cleans itself and the air around it.

As a photocatalyst, titanium dioxide interacts with sunlight to break down organic matter on and around the surface of building panels, leaving organic matter on the surface of an aluminum composite panel ready to be washed away. When it rains, water doesn't bead on the surface, but instead runs evenly down the building, removing grime and pollutants.

Buildings are exposed to many organic contaminants. From bird residue to diesel fumes, architectural building panels are constantly exposed to organic material that makes these surfaces appear dirty.

Nitrogen oxide is an organic material constantly bombarding buildings that is harder to see. As the primary component of smog, nitrogen oxide makes buildings dirty and threatens the quality of outdoor air. When nitrogen oxide molecules float near the surface of titanium dioxide coil-coated aluminum architectural panels, they are attacked by free radicals generated from the titanium dioxide reacting with water and oxygen in the air. The free radicals oxidize the nitrogen oxide molecules, converting them into harmless nitrates. Other contaminants are similarly broken down through sunlight's reaction with titanium dioxide, leaving them ready to be washed away. Titanium dioxide coil-coated aluminum architectural panels effectively remove pollutants by using sunlight, water vapor, and oxygen to clean the air.

Once the titanium dioxide has done its job—broken down and destroyed the nitrogen oxide and other organic matter on the aluminum composite material—a second major benefit, creating a superhydrophilic surface, comes into play.

Because the titanium dioxide coil coating is superhydrophilic, the surface of aluminum composite materials becomes very slick in the presence of water. Instead of beading on the surface, rainwater runs evenly off the aluminum panels, taking most of the organic matter and nitrates with it. This helps eliminate the tiger-striped look that often appears on building surfaces around caulk joints, air ducts, and roof water discharge points. The slightest amount of rain or humidity in the air creates the effect; even morning dew activates the process. Each time it does, the water running off the building carries away broken-down contaminants, leaving the building surface cleaner.

Reduced Maintenance Costs

By constantly breaking down organic matter through its photocatalytic properties, and washing material away through its superhydrophilic properties, titanium dioxide coil-coated aluminum architectural panels can significantly reduce facility maintenance costs. This process helps maintain the building image and appearance over time as first requested by the owner and envisioned by the architect.

The primary indicator that a titanium dioxide coating is working effectively is the building appearance. When exposed to UV light, exterior building panels treated with titanium dioxide coating will be cleaner than those of surrounding structures. The reaction that enables the building surface to maintain its appearance works equally in removing smog and other pollutants. Based on independent testing, findings from a scientific third party confirm that a titanium dioxide coating neutralizes smog.

Studies show that 10,000 square feet of a titanium dioxide coil-coated aluminum architectural panel have the approximate cleansing power of 80 trees. This is the equivalent of offsetting smog created by the pollution output of four cars daily.

The potential environmental and maintenance cost-saving benefits of using high-performance titanium dioxide coil-coated aluminum architectural panels can be quantified. Building owners can forecast savings in operational and maintenance costs while avoiding the use of cleaning chemicals.

An online evaluator tool can determine the equivalent number of trees and cleansing power a building can achieve per day, and the pollution from the number of cars a building can potentially remove from the road per day. Calculations estimate the potential savings generated over time by decreasing the frequency of building cleanings.

These estimates are based on research conducted by the U.S. Forest Service. Removal rate averages were calculated using average pollution removal capacities of urban forests in 55 U.S. cities. Car pollution rates are based on California emission standards, and assume nitrogen oxide pollution by a gas-powered car driving 50,000 miles over five years.

Three variables are used to determine cost savings: wall siding area of the building, the number of times per year the building is cleaned, and anticipated building façade cleaning costs. Based on this model, with the application of titanium dioxide coil-coated aluminum architectural panels, a 10,000-square-foot building cleaned once a year, at $0.15/sf average cost from market studies, could potentially realize a maintenance cost savings of $1,300 annually. This represents the approximate air cleansing power of 80 trees, and the cleaning power to offset the smog created by pollution output of four cars per day.

Depending on location and building height, building cleaning costs may range from $0.05/sf for lower cost locations and low-rise buildings, yielding a $450 annual maintenance savings to $0.35/sf in higher cost locations for low- to mid-rise buildings, yielding a $3,450 annual maintenance savings.

Aluminum Ceilings

Metal ceiling systems provide a greater range of finishes than acoustical ceilings made of mineral fiber or fiberglass. Typical finishes include baked-on paint in standard or custom colors, metallic paints, and wood grains in polymer and powder coat. Metal ceiling systems provide owners with a durable ceiling that allows frequent access to plenum areas without damage to the panels. These systems are sustainable, highly recyclable, cleanable, and promote indoor air quality because they contain no organic compounds to support mold and microbial growth. Because of metal's durability, these systems may be used in exterior environments to create soffits, and can be engineered to withstand positive and negative air pressures.

Interior and exterior linear metal ceilings provide visual continuity and performance at a Go Transit Station in Brampton, Ontario, Canada. Consulting engineer: R.J. Burnside & Associates Ltd. Photo by Bochsler Creative Solutions, Burlington, ON; courtesy of Chicago Metallic