Larson Sidelite Storm Panel with Low-E Glass

Larson’s sidelite storm panels transform drafty, energy-draining sidelites into sealed, insulated components that actually contribute to the entryway’s thermal performance. Up to 60% reduction in energy loss (L705) and 24% better insulation than clear glass (I200E) — measurable savings that contractors can quote with confidence. The panels come in Width: 7 in. to 30 in.; Height: 24 in. to 97 in., covering virtually any residential sidelite configuration from narrow Victorian-era openings to modern full-height installations.

The real value shows up in three places: energy bills drop measurably, outside noise cuts in half, and those annoying drafts around the entry door finally stop. For Montana contractors dealing with -20°F winters and clients tired of feeling cold air pour through their sidelites, these panels solve a specific problem with quantifiable results.

Technical Performance That Matters

The numbers tell the story contractors need to hear. Proven 50% reduction in outside noise (I200E) turns a busy street location into a quiet interior. Reduces air leakage by up to 75% (I200E) using bulb weather-seals — that’s the difference between feeling drafts and forgetting the sidelite exists. The Rated for up to 90 mph wind (I200E) with a double-wall frame specification matters in Montana’s wind corridors and chinook-prone areas.

Specification	L705 Model	I200E Model	Source
Energy Loss Reduction	Up to 60%	24% better than clear glass	manufacturer
Noise Reduction	Not specified	50% reduction	manufacturer
Air Leakage Reduction	Not specified	Up to 75%	manufacturer
Wind Rating	Not specified	90 mph	manufacturer
Glass Type	Tempered Low-E	Low-E (ENERGY STAR)	manufacturer
Mount Type	Exterior Overlap	Interior Jamb Mount	manufacturer

The Low-E coating reflects heat and reduces sun fading on interior furnishings, addressing both summer heat gain and UV damage to flooring and furniture near the entry. For south-facing entries in Montana’s intense high-altitude sun, that UV protection prevents expensive interior damage.

Installation Flexibility for Real-World Conditions

Montana’s older homes rarely have square openings. Larson designed around this reality — the I200E model tolerates up to 3/8 in. for out-of-square openings. That’s the difference between a straightforward install and hours of shimming and adjusting.

Two mounting approaches handle different situations. The L705 exterior overlap mount fits over the existing opening; secured with mounting screws and finished with screw-cap covers; removable from outside. Simple approach for straightforward retrofits. The I200E interior inside-mount (jamb mount); installable in approximately 10 minutes with minimal screws; tilt-in sash for easy cleaning preserves exterior trim details — critical for historic homes or HOA-restricted properties.

The custom sizing from 7 to 30 inches wide and 24 to 97 inches tall handles everything from narrow Victorian sidelites to modern floor-to-ceiling panels. Standard UI ranges from 41 to 144 inches for the I200E model, using the industry-standard United Opening Inches measurement system.

Built for Montana’s Climate Demands

ENERGY STAR certification for Northern and North-Central climate zones directly applies to Montana’s heating-dominated climate. The panels earn this certification through measurable performance, not marketing claims. L705 features tempered glass for added strength — required safety feature that also handles thermal stress better than standard glass.

The 10-year warranty on components including glass backs up the durability claims. Accidental glass-breakage coverage included with I200E model adds peace of mind for high-traffic entries where kids, dogs, or furniture moves create risk.

The Bottom Line

Larson sidelite storm panels deliver three measurable benefits: dramatic energy loss reduction (up to 60%), proven noise reduction (50%), and nearly eliminated air infiltration (75% reduction). The custom sizing capability means they’ll fit virtually any residential sidelite, while the tolerance for out-of-square openings saves installation headaches.

For contractors quoting energy upgrades, these panels offer quantifiable improvements clients can understand. Show them the 60% energy loss reduction number. Explain how 50% noise reduction transforms a busy street location. Demonstrate how 75% less air infiltration means no more cold drafts around the entry door.

The ten-minute interior installation option makes this a profitable add-on service. The exterior mount version provides a solution for situations where interior mounting won’t work. Either way, contractors can offer clients a measurable improvement in comfort and energy efficiency without the cost and complexity of full window replacement.

Frequently Asked Questions

Q: What’s the actual energy savings I can promise clients?

A: The L705 model delivers up to 60% reduction in energy loss through the sidelite. The I200E provides 24% better insulation than clear glass. These are manufacturer-tested numbers you can quote confidently. How much that translates to in reduced heating costs depends on the home’s specific situation and number of sidelites.

Q: How much out-of-square can these panels handle?

A: The I200E interior mount model tolerates up to 3/8 inch out-of-square openings. That covers most settling issues in older homes. The L705 exterior overlap mount is even more forgiving since it mounts over the existing opening rather than inside it.

Q: Do these panels require special glass for safety codes?

A: The L705 model comes with tempered safety glass as standard equipment. The I200E uses Low-E glass that’s ENERGY STAR certified. Both meet typical residential safety requirements for sidelites.

Q: What’s the real installation time for the interior mount version?

A: Larson claims approximately 10 minutes for the I200E interior mount installation. That’s realistic for a square opening with good access. Add time for measuring, minor adjustments, and cleanup — figure 30 minutes total per panel for accurate job quotes.

Q: How do these handle Montana’s wind conditions?

A: The I200E model carries a 90 mph wind rating with its double-wall frame construction. That exceeds typical Montana wind speeds, even in chinook-prone areas. The bulb weather-seals maintain their seal under wind pressure.