Published: 09/20/2026Updated: 09/20/2026

Quick Answer:

Traditional aluminum spacers act as thermal bridges that carry extreme outside temperatures directly into your home, causing heavy heat loss and persistent window condensation. Replacing failed glass units with low-conductivity XL Edge warm-edge spacers breaks this cold bridge, dramatically improving year-round energy efficiency without requiring a full window replacement.

Condensation or frost on the inside of a window due to below-freezing temperatures can indicate a ‘cold bridge’ at the edge of your window. In the suburbs of Chicago, many homeowners believe the window frame material is a key factor in insulation effectiveness, but it’s really the spacer (located between the two sheets of glass) that has the most influence on the amount of heat lost or gained through your window. At FixHomeGlass, we want to help you reduce energy costs by showing you how cold bridges work.

What is a Cold Bridge?

Historically, double-pane windows were manufactured using aluminum to separate the two sheets of glass. However, aluminum is a highly conductive metal. In the winter, it acts as a thermal bridge, literally “carrying” the freezing outdoor temperatures directly to the inner pane of glass. Historically, double-insulated windows used aluminum spacers between the glass panes. Unfortunately, since aluminum is such a good conductor of heat, it allows the outside temperature to flow through the spacer into the inside glass during the winter. As a result, there is a significant amount of heat loss through the cold bridges created by the aluminum spacers. The consequences of using an aluminum thermal bridge include:
  • Massive Heat Loss: Large amounts of energy are lost through the edge of your window during the coldest months.
  • Persistent Condensation: The cold edge causes moisture to reach its “dew point” and turn into liquid or ice on the glass surface.
  • Structural Damage: Constant moisture buildup leads to a much higher risk of mold growth or wood rot on your window frames.

The XL Edge Solution: Breaking the Bridge

FixHomeGlass uses only XL Edge insulating glass units, manufactured by Cardinal Glass Industries to resolve this issue. The patented multi-layer design with stainless steel in the centre is the only construction which will stop the transfer of heat between a side of the glass and an edge sealant due to the very low heat conductivity of stainless steel compared to aluminium. Therefore, the edges of the glass remain warmer than what occurs with the traditional use of aluminium spacers. Because of this “warm edge” technology, the temperature at the inside edge of the glass will typically not reach dew point, preventing visible condensation occurring at the inside edges of the glass. 

Efficiency for Every Season

One myth about replacing a window is that people only take thermal bridges into consideration in the winter time. At FixHomeGlass, we are able to perform glass installations all year because high performance spacers are equally necessary during the humid summer months in Illinois. In the summer time, an XL Edge warm edge spacer prevents the extreme outside temperatures from transferring to your cooled living area. When you only replace the failed seals in your existing frames with XL Edge technology, you essentially get the benefits of a completely new window for a fraction of the price. 

Why the Spacer Matters for Your Warranty

Besides providing an airtight barrier preventing the cold air from transferring to your window frame, the spacer serves as the structural backbone of your Insulated Glass Unit (IGU). The construction of the XL Edge frame provides a moisture-tight seal to the IGU preventing the ingress of moisture and insulating your argon gas for decades to come.  When you choose FixHomeGlass, you can expect to receive:
  • Statistically Proven Quality: Cardinal units have a failure rate of just 0.20% over 20 years.
  • 20-Year Warranty: We stand behind our work with a premier thermal seal warranty.
  • No Polymer Design: Our units eliminate the risk of chemical fogging within the glass.
  • Transparent Pricing: We provide a fixed individual price after our free consultation, so you know exactly what your energy-saving upgrade will cost.

Frequently asked questions

What is a "cold bridge" in double-pane windows?
A cold bridge occurs when highly conductive materials, like traditional aluminum spacers between glass panes, transfer cold outdoor temperatures directly to the inner glass surface. This causes substantial heat loss during winter and creates cold spots along the window edges.
When cold bridges lower the temperature of the interior glass edge to the "dew point," ambient indoor air moisture condenses into liquid or frost. Over time, this constant moisture buildup can damage window sills and trigger mold growth or wood rot.
XL Edge spacers use low-conductivity materials, including a stainless steel core, to restrict heat transfer between the inner and outer glass panes. This keeps the interior glass edges warmer in winter and cooler in summer, preventing condensation and lowering heating and cooling costs.