Volume 36, Issue 10, October 2001

Increase Your Flexibility
        Gaining a Competitive Edge with a Flexible Spacer System
by Scott Casselden

Eighty-two percent of all insulating glass (IG) units in North America are constructed with energy-efficient warm-edge spacers. (This percentage is based on AAMA/WDMA North America Industry Market Studies 2000 produced by Ducker Research Company Inc.) This number is expected to continue its climb due to the increased emphasis on energy efficiency. Now, you not only need to incorporate a warm-edge spacer system in your window lines, you need to select the right one—the system with performance features that are most desirable in your market.

In such a competitive market, it can be fatal to make a mistake when choosing a warm-edge spacer system. To make an informed choice, you need to look at nine key factors: integration, thermal performance, durability, automation, productivity, equipment capital, flexibility, installed cost and suppliers.

Integration and Thermal Performance
Component integration refers to the level of integration of the warm-edge components, or how many different components are required in the assembly of an IG unit. All-in-one spacers reduce physical inventory, offer built-in quality control and a potentially higher level of productivity. Although higher-priced in respect to material costs, all-in-one systems may reduce total costs.

A key criterion for choosing a warm-edge spacer system is thermal performance. Due to rising energy costs and the efforts of organizations and programs such as ENERGY STAR® and the National Fenestration Rating Council, consumers have a greater awareness of the benefits of energy-saving products. Consequently, consumers are demanding thermal performance in their windows. To remain competitive, you will need to offer high-performance windows that save energy. 

Flexibility, Productivity and Durability 
Another important criterion is flexibility. Flexibility is defined as the ability of the system and equipment to meet market needs, seasonal demands and growth expectations. Market needs include current and future demand for standard production, remakes, odd shapes, gas-filled units and multiple glazings. Seasonal demand refers to the ability of production equipment to fabricate IG panels efficiently during all phases of a window manufacturer’s business year. 

Productivity of the fabrication equipment is also an important factor. The accepted method of measuring productivity is in units per man hour (UPMH). Although potentially beneficial, increasing UPMH can be a challenge given the many variables affecting productivity.

With the trend of enhanced warranties, durability is another key criterion. Durability can be defined simply as the service life of a unit. To determine the service life of an IG unit, consider these four factors:
    • moisture vapor transmission rate;
    • configuration—seal or dual seal;
    • type of IG sealant; and
    • historical performance.

Automation is often desired when considering warm-edge spacer alternatives. Key automation opportunities include: 
    • glass handling;
    • frame manufacturing;
    • glass and frame positioning; and
    • sealant application.

Cost Considerations
Next, look at equipment capital. You must first establish current future production demands as well as product mix before selecting equipment. Also, seek out the advice and recommendations of equipment vendors and visit other window manufacturers that have similar production demands to evaluate the effectiveness of their systems. 

To determine the spacer system’s total installed cost, another key criterion you need to calculate is the cost of equipment capital per unit. Generally, we assume the life expectancy of equipment to be approximately seven years and the residual value at this time to be approximately 35 percent. 

The cost of capital per unit can be calculated as: Capital Cost per Unit = Total Capital x 0.65 ¸ the number of units over seven years.

Remember, you are choosing more than equipment when you select a warm-edge spacer system. Potential suppliers should be companies that can be considered long-term partners of your business. 


Scott Casselden
is the national sales manager for TruSeal Technologies Inc. in Beachwood, Ohio. Fenestration Focus appears quarterly.


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