Question 1

What glass makeup should I use for a walk-in freezer door?

Accepted Answer

THERMGLASS Hybrid VIG is recommended for walk-in freezer doors (-10°F to +10°F interior). It combines a vacuum unit with an IGU argon-fill cavity, achieving a COG U-factor of 0.039 Btu/h·ft²·°F and Condensation Resistance of 85+. For blast freeze chambers (-40°F and below), Hybrid VIG with a heated gasket system is required.

Question 2

How do I calculate the dew point for my cold storage glass door?

Accepted Answer

The THERMGLASS Cold Storage Configurator calculates the ambient dew point using the Magnus formula based on your store ambient temperature (°F) and relative humidity (%). It then compares the estimated glass surface temperature against the dew point to flag condensation risk and recommend the appropriate VIG makeup.

Question 3

What is the energy savings from switching to vacuum glass in a refrigerated display case?

Accepted Answer

THERMGLASS VIG reduces conductive heat gain through the glass door by 71–91% compared to a standard double-pane IGU reference (COG U-factor 0.28 Btu/h·ft²·°F). This directly reduces compressor runtime and significantly reduces anti-sweat heater electrical load, delivering measurable utility cost reductions across a full display case lineup.

Question 4

Can THERMGLASS VIG be retrofitted into existing walk-in cooler door frames?

Accepted Answer

Yes. THERMGLASS Standalone VIG profiles start at 6.3mm — thin enough to fit most existing door frame rebates designed for standard double-pane IGU. This enables a direct drop-in retrofit of walk-in cooler and display case doors without frame replacement, delivering vacuum-grade thermal performance in the existing door system.

Question 5

What glass is best for walk-in cooler doors?

Accepted Answer

For walk-in coolers (28°F to 38°F interior), THERMGLASS Standalone VIG delivers a COG U-factor of 0.079 Btu/h·ft²·°F and Condensation Resistance of 77 — sufficient to prevent condensation in most retail ambient conditions without a heated frame. The slim 6.3–8.3mm profile fits standard walk-in door frame rebates as a direct drop-in replacement for conventional double-pane IGU.

Question 6

How do I prevent condensation on cold storage glass doors?

Accepted Answer

Condensation on cold storage glass doors forms when the glass surface temperature falls below the ambient dew point. The primary prevention strategy is increasing the glass thermal resistance — THERMGLASS VIG raises the inner glass surface temperature by 71–91% compared to standard IGU, keeping it above the dew point in typical retail ambient conditions (70–75°F, 50–60% RH). For high-humidity environments or blast freeze applications, a heated ITO anti-fog glass lite or heated gasket system provides additional protection. The THERMGLASS Cold Storage Configurator calculates your specific dew point and condensation risk based on your ambient temperature and relative humidity inputs.

Question 7

Is THERMGLASS cold storage glass NSF/ANSI 7 compliant?

Accepted Answer

NSF/ANSI 7 governs the complete commercial refrigerator or freezer cabinet — including material safety, cleanability, corner radii, corrosion resistance, and temperature retention. Individual glass panes do not hold NSF/ANSI 7 certification; only the completed OEM cabinet receives NSF listing. THERMGLASS VIG is engineered to support OEM cabinet compliance with NSF/ANSI 7 sanitation and DOE 2023 energy efficiency standards. The Cold Storage Configurator flags this contribution in the output datasheet for applicable application types including reach-in display cases, open-front merchandisers, and walk-in cooler and freezer doors.

Question 8

What is the difference between Standalone VIG and Hybrid VIG for cold storage?

Accepted Answer

Standalone VIG is a single vacuum insulating glass unit — two glass panes with a sub-millimeter vacuum gap, sealed with a warm-edge perimeter bond. It achieves a COG U-factor of 0.079 Btu/h·ft²·°F (R-12.6) in a 6.3–8.3mm profile, making it ideal for walk-in coolers, reach-in display cases, and medium-temperature applications. Hybrid VIG pairs a vacuum unit with an additional IGU cavity (air or argon fill), achieving a COG U-factor of 0.039 Btu/h·ft²·°F (R-25.6) in a 14–20mm profile. Hybrid VIG is required for walk-in freezers, blast freeze chambers, and any application where interior temperatures fall below 0°F.

Question 9

Does THERMGLASS cold storage VIG meet ASHRAE 90.1 energy code requirements?

Accepted Answer

Yes. ASHRAE 90.1-2022 sets a maximum whole-unit U-factor of 0.25 Btu/h·ft²·°F for refrigerated case doors. THERMGLASS Standalone VIG achieves a whole-unit U-factor of approximately 0.10–0.12 Btu/h·ft²·°F and Hybrid VIG achieves 0.06–0.08 Btu/h·ft²·°F — both well below the ASHRAE 90.1 threshold. The Cold Storage Configurator outputs ASHRAE 90.1 compliance status in the results datasheet based on your specific makeup and frame system selection.

Cold Storage VIG Configurator

Walk-In Coolers & Freezers

Refrigerated Display Cases

Related Resources

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