
Hand-Soldered Window Grids
Heritage Thermal Windows began by building decorative grid windows in thermal units for owners of historic homes back in the 1990s. Conservation of energy as well as the aesthetic preservation of old homes and other edifices was the objective.
To retrofit steel sash windows is remarkably affordable. In most cases, there is no need (or cost) to replace the window frame or sash—only the pane, with a new decorative metal grid thermal unit. (See video.)
The cost of replacement is amortized over years of energy savings with dual-sealed (polyisobutylene primary, pure silicon secondary) thermal windows.
It is a beautiful marriage of old and new—aesthetics and energy-saving technology.
Services
Choose Your Design
Diamond, rectangular, or a design of your choosing.
We’ve been doing custom window work for decades.
Traditional Metals With Thermal Efficiency
Hand-soldered metal mullions enhance architecture with an air of charm and a classic touch.


Applications & Construction
Applications
These thermal units may be installed in newer vinyl, wood, or fiberglass sashes.
They may also be used to replace existing clear thermal units and installed in the existing sash as long as the dimensions are the same. ( Width x Height x Thickness)
Construction
These thermal units are available in thicknesses measuring from 1/2″ to 1″ for flat came and 5/8″ to 1″ for round.
There is clear glass on the front and back, with the decorative metal grid inside the unit.
The dual-seal on the thermal unit is a polyisobutylene primary and pure silicon secondary. This is acknowledged as the superior sealing system in the industry for insulated glass units (I.G.U.s)
You don’t ever want to deal with a seal failure, and neither do we. Our track record is superb.
Warranty
Warranty
Heritage Thermal Windows are based and built in the U.S.A.
This window unit is warranted against defects in materials and workmanship for a period of 20 years, as long as it is used for its intended purpose. Damage arising from shipping, mishandling, installation, or accidental or intentional impacts are expressly excluded, and all other express or implied warranties, including but not limited to those of merchant-ability or fitness for any other purpose, are disclaimed. The remedy for any breach of warranty will be limited to replacement of the unit.
– God Bless America –
Manufacturing Process
Finest Quality Materials
Heritage Thermal Windows are hand-soldered decorative metal grids (mullions) custom built to your specifications.
- Clear Double Strength (DS) Glass.
- Decorative grids are zinc construction with antique finish.
- Tempered glass upon request.
- Aluminum spacer tube containing dessicant.
We use laser-welded aluminum spacer tubes filed with desiccant and a dual-seal.
Tempered glass & argon gas-filled units are optional.
The thermal units measure from 1/2″ to 1″ thick, depending on the metal came used.



What’s a Came?
Came is the industry term for the zinc metal grid that we hand-solder and mount between two panes of glass.
Our standard zinc came dimensions are 1/4″ or 3/8″ flat, or 7/32″ round.
Replace Existing Glass
Heritage Thermal Windows can be used to replace existing clear glass thermal units as long as the dimensions are the same.
Installation Procedure
Installation into the sash should follow the window manufacturer’s recommended procedures.
Tempered Glass
Tempered glass should be used in doorways, sidelights, and bathrooms. Check your local building codes.
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