The doored-vs-open debate in grocery refrigeration was settled on energy a decade ago — glass doors win by 50-60%. The remaining question is sales-lift impact, and the 2026 data has shifted in glass doors' favor as merchandising patterns have evolved.
Open multi-deck cases continuously dump cold air into the sales aisle and pull warm humid sales-floor air into the case across the air curtain. Glass-door cases have a near-zero air exchange except during the brief moments doors are open. Modeled annual energy consumption for a typical 50-foot dairy lineup: open multi-deck ~85,000 kWh/year; glass-door equivalent ~35,000 kWh/year. At Tampa Bay commercial blended rates that's roughly $6,500/year saved per 50 ft of lineup.
Glass-door dairy cases run roughly 15-25% higher capex per linear foot than open multi-decks at equivalent product capacity. The energy payback of the premium is typically 4-7 years at Tampa Bay rates, before any sales-lift considerations.
Operational cost: glass doors require gasket replacement every 3-5 years and anti-sweat heater maintenance. Open multi-decks require honeycomb maintenance and more frequent coil cleaning due to airflow path. Lifetime maintenance cost is roughly comparable.
Through the 2010s, multiple grocery industry studies found that converting open multi-decks to glass doors caused a 3-7% sales decline on impulse SKUs (yogurt, dressings, beverages). Operators concluded that the visual access of open cases drove higher pickup rates and that glass doors hurt margin where it mattered.
More recent industry data through 2024 shows the sales penalty has compressed substantially — typically 0-3% on impulse SKUs and effectively zero on planned-purchase SKUs (milk, juice, large containers). Several factors: glass-door product has dramatically improved (LED lighting, anti-sweat clarity, faster door return), shopper acceptance has risen as glass doors became universal in newly-built stores, and digital shopping behavior has shifted impulse purchasing online anyway.
Some categories now show sales increases on glass-door installations — especially beverages, where the glass-door cooler form factor improves planogram density and brand visibility.
Open multi-decks struggle harder in Tampa Bay than in drier climates. Sales-floor humidity above 55% reduces case capacity and accelerates anti-condensate energy use. Glass doors are essentially indifferent to ambient humidity. For an operator running a fleet with consistent merchandising standards, Tampa Bay stores see disproportionately larger benefit from glass-door conversion than the same conversion would deliver in Phoenix or Dallas.
Retrofitting open multi-decks to glass doors in existing cases is sometimes possible but more often the right answer is full lineup replacement during a planned remodel. Replacement cost for a 50-foot dairy lineup: $80K-$120K installed in Tampa Bay 2026. Energy savings of $6,500/year + reduced refrigerant load + improved case temperature control + 25-year service life put the all-in payback at 12-18 years — slow but reliable.
The better framing: any planned dairy remodel in 2026 should default to glass-door specification unless there's a specific merchandising reason not to.
Two categories where open multi-decks remain the right tool: (1) fresh produce sales-floor merchandisers where misting and the visual appeal of unencumbered product matters; (2) specialty cheese and prepared-food selection cases where shopper-staff interaction is part of the experience. Most other categories have moved or are moving to glass doors as natural lineup turnover allows.
Roughly 50-60%. A typical 50-foot open multi-deck dairy lineup consumes about 85,000 kWh/year; the glass-door equivalent runs about 35,000 kWh/year. At Tampa Bay commercial rates that's about $6,500/year per 50 feet of lineup.
Historically yes — 3-7% decline through the 2010s. More recent data through 2024 shows the penalty has compressed to 0-3% on impulse SKUs and effectively zero on planned purchases. Some beverage categories now show sales increases on glass-door installations.
For most Tampa Bay grocery operators, default to glass-door specification on planned remodels and natural lineup replacements. In-place retrofits are sometimes possible but more often complicated; plan the conversion as part of normal capex cycles, not as a standalone project.
$80K-$120K installed in 2026 pricing for a glass-door lineup, slightly less for open multi-deck. Energy savings, refrigerant reduction, and improved temperature control put glass-door all-in payback at 12-18 years.
Suncoast Cold Systems handles exactly this kind of commercial refrigeration issue across Tampa, St. Petersburg, Clearwater, Brandon, Riverview, Temple Terrace, and Wesley Chapel. 24/7 dispatch. Licensed Class A A/C Contractor (FL #CAC1824642), EPA 608 Universal, OSHA 30 Construction.
What goes wrong on the doored cases and what it costs.
Glass-door retrofit math vs other grocery energy projects.
When the open cases you have are misbehaving.