For most supermarkets, the right answer is not one or the other — it is a mix. Open multideck chillers drive impulse sales on high-turnover dairy, drinks, and grab-and-go items. Glass door chillers cut energy use by up to 40-50% and hold temperature steadier overnight. The real question is which categories go where, and what that means for your operating cost per linear foot.
How Open Multideck Chillers and Glass Door Chillers Actually Differ
An open multideck chiller uses a refrigerated air curtain flowing down across the front opening to keep product cold while letting shoppers reach in without opening a door. The back wall and base deck hold the evaporator coil and fans. Product sits on adjustable shelves, fully visible and fully accessible.
A glass door chiller is a sealed cabinet with front glass doors — typically double- or triple-pane low-E glass with an argon fill. The doors are either hinged or sliding. A heated door frame prevents condensation and fogging so the product stays visible. The compressor cycles less often because cold air is not spilling into the aisle.
The core difference is physical: one relies on an air curtain that must be engineered carefully, the other relies on a sealed box that any refrigeration tech understands. Each approach changes how the store feels, how energy is used, and how shoppers behave.
Common Configurations
Open multidecks come in modular lengths — 3 ft, 4 ft, 6 ft, 8 ft, and 12 ft sections — that connect to form longer runs. They are almost always medium-temperature (35-41 °F / 2-5 °C). Glass door chillers come as single-door (23-30 inch) or double-door (47-60 inch) cabinets, often 72-80 inches tall, and are available in medium-temperature and low-temperature (freezer) versions.
Both formats can be remote (tied to a store-wide compressor rack) or plug-in (self-contained with onboard compressor). Remote units are quieter on the sales floor but require a machine room or rooftop condenser. Plug-in units simplify installation and make it easier to relocate departments later.
Energy Consumption: The Real Operating Cost Difference
The energy gap is the single biggest reason buyers move from open to glass door. Open multideck chillers fight ambient air 24 hours a day. The air curtain works well in a climate-controlled store, but every degree of room temperature above 75 °F pushes compressor run time higher.
Independent refrigeration studies and manufacturer data consistently show glass door chillers using 40-50% less electricity per linear foot than open multidecks serving the same temperature range. In a 20-door supermarket, that difference can run into $3,000-$8,000 per year depending on local utility rates.
Night blinds — insulated covers pulled down over open multidecks after hours — can close part of that gap. A decent night blind cuts overnight energy use by 25-35% on an open chiller. But night blinds add a manual step for staff, and if they are not pulled every night, the savings disappear. Glass doors need no such routine.
Humidity and Defrost
Open chillers pull in humid store air constantly, which means more frost on the evaporator coil and more frequent defrost cycles. Electric defrost heaters fire several times a day, each cycle burning energy and briefly warming the case. Glass door cabinets, sealed against ambient moisture, defrost less often — another point where the operating cost tilts toward glass doors.
Product Visibility vs Temperature Stability: The Merchandising Trade-Off
The “open” in open chiller is a merchandising tool. No barrier between the shopper and the product means a higher impulse grab rate. Dairy, packaged sandwiches, bottled coffee drinks, yogurt cups — items people decide to buy on the spot — sell better from open multidecks. Multiple industry surveys (including studies referenced by the UK Carbon Trust and US DOE Better Buildings program) put the impulse sales lift at 15-30% for accessible open displays.
Glass door chillers do not kill sales, but they do add a small friction step. For planned purchases — a gallon of milk, a bag of frozen peas, a case of soda — shoppers open the door without hesitation. The sales difference largely disappears for these categories.
Temperature stability runs the other way. Glass door cabinets hold a tight band — often within +/- 1 °F of set point — because the cold air stays in. Open multidecks can show 3-5 °F variation from shelf to shelf, especially near the air curtain discharge at the top and the return at the bottom. Products near the return air grille may run warmer. Deli meats, fresh-cut produce, and temperature-sensitive dairy need that tight control more than bottled drinks do.
Comparison Table: Open Chiller vs Glass Door Chiller at a Glance
| Factor | Open Multideck Chiller | Glass Door Chiller |
|---|---|---|
| Energy use per linear ft | Higher — air curtain runs continuously; 40-50% more than glass door equivalent | Lower — sealed cabinet; compressor cycles less |
| Product temperature stability | Moderate — 3-5 °F variation shelf to shelf; affected by store ambient | Tight — typically +/- 1 °F; unaffected by aisle conditions |
| Impulse sales lift | 15-30% above door units for grab-and-go categories | Baseline — planned-purchase items see little difference |
| Defrost frequency | Higher — humid store air drawn in constantly | Lower — sealed cabinet limits moisture ingress |
| Night blinds/after-hours saving | Optional night blinds recommended; 25-35% overnight energy reduction when used | Not needed — doors already seal the cabinet |
| Noise on sales floor | Louder — air curtain fans run continuously plus compressor noise (if plug-in) | Quieter — fewer fans, sealed cabinet dampens sound |
| Maintenance access | Front and rear access typical; evaporator coil needs regular cleaning | Front-access typical; condenser coil cleaning on plug-in units |
| Typical temperature range | Medium-temp: 35-41 °F (2-5 °C) | Medium-temp (35-41 °F) and low-temp/freezer (-10 to 0 °F) |
| Installation complexity | Remote: refrigerant piping to rack; Plug-in: power + drain | Same: remote or plug-in options available |
| Best product fit | Dairy, drinks, packaged deli, sandwiches, impulse items | Bottled drinks, fresh produce, frozen foods, bulk dairy, overnight holding |
| Glass type | None — air curtain only | Double- or triple-pane low-E glass, argon-filled, heated frame |
| Typical door/case width | 3-12 ft modular sections | Single door: 23-30 in; Double door: 47-60 in |
| Frost/fog on display face | Not applicable — open front | Prevented by heated door frame and low-E glass coating |
| Approximate lifespan | 8-12 years with proper maintenance | 10-15 years — fewer compressor cycles extend compressor life |
What to Inspect Before You Buy (Specs, Materials, and QC Points)
When you are comparing quotes — especially sourcing from overseas manufacturers — a handful of spec points separate a case that lasts 10 years from one that needs a compressor swap in year three.
Compressor and Refrigeration Components
Ask which compressor brand is quoted. Danfoss, Copeland (Emerson), Secop, and Tecumseh are the established names. Some Chinese manufacturers also use domestic compressor brands like Huayi or Donper that work fine but have shorter track records outside China. Confirm the quoted compressor model number, not just the brand — within a brand, there are economy and commercial-grade lines. The compressor warranty term (typically 2-3 years for the compressor itself) should be in writing.
Cabinet Construction and Materials
Open multideck bodies are usually powder-coated galvanized steel. Stainless steel interior floors and back panels hold up better against spills and daily cleaning. Check the paint spec — polyester powder coat is standard; epoxy-based coatings add corrosion resistance for coastal or high-humidity stores.
Glass door cabinets should specify double-pane low-E glass at minimum. Triple-pane gets you another 10-15% energy improvement but adds door weight, so hinges and frame spec matter. The door frame heater (anti-sweat heater) should be low-wattage — older designs run hot and waste energy. Heated glass (where a transparent conductive coating warms the glass itself) is the most energy-efficient anti-fog approach.
Shelving and Weight Rating
Standard shelves hold 60-100 lbs per linear foot. If you are stacking gallon milk jugs or glass-bottle beverages, ask for reinforced shelving rated at 120-150 lbs per foot. Shelf pitch (angle) should be adjustable — flat for packaged goods, slight tilt for bottles that need to slide forward.
LED Lighting
Most cases now come with LED lighting as standard, but confirm placement: canopy lighting (top-down, under the header), shelf-edge lighting, and vertical pilaster lighting affect how product looks. Vertical LED strips in the mullions of a glass door chiller eliminate shadows better than canopy-only lights.
Controller and Defrost
The electronic controller should support programmable defrost intervals (time-based or adaptive) and show error codes in plain language, not just blink patterns. If the store operates in a humid climate (Southeast US, Gulf Coast, Southeast Asia), adaptive defrost that senses coil frost is worth the upgrade.
Packaging and Shipping Damage Prevention
Glass door chillers need extra crate attention: each door should be braced with foam blocks, the door hinges locked, and the crate marked “this side up” with tilt indicators. Open multidecks need corner guards under the crate wrap and foam between bolted-together sections. Ask for crate photos from the factory before they ship — it catches 80% of packaging problems before the container leaves.
Which Setup Fits Your Store Format?
There is no universal best answer, but the store type usually points toward a clear starting point.
Full-line supermarket (15,000+ sq ft): Run open multidecks along the dairy and drinks wall and in the grab-and-go deli island. Use glass door chillers for the beverage cold vault, frozen food aisle, and back-of-house holding. The blended approach maximizes impulse sales up front and cuts energy cost on the long-run aisles.
Convenience store or gas-mart (2,000-5,000 sq ft): Glass door reach-ins dominate here — energy cost matters more, staff count is small, and the product mix leans toward bottled drinks and packaged snacks. One short open multideck for sandwiches and fresh food can work if turnover is high enough (restocking at least twice daily).
Specialty food retailer (cheese shop, butcher, bakery): Open multidecks or service-over counters with curved glass are the norm — the open display is part of the shop experience. Glass door units handle backup stock in the back.
Hotel or restaurant back-of-house: Glass door reach-ins almost exclusively. Visibility to guests does not matter; temperature holding and energy efficiency do.
Plug-In vs Remote: A Practical Note
If you are renovating an existing store and cannot touch the machine room, plug-in (self-contained) cases keep the project simpler — each case needs only a power outlet and a condensate drain. The trade-off is compressor noise on the sales floor and a bit more heat rejected into the store. Remote cases are quieter and more efficient for large installs (6+ doors or 20+ linear feet), but they add piping, a rack, and commissioning labor to the upfront cost.
FAQ
Are open chillers more expensive to run than glass door chillers?
Yes. Open multideck chillers typically consume 40-50% more electricity per linear foot because the refrigerated air curtain fights ambient air 24/7. Glass door cabinets seal cold air in, so the compressor runs fewer hours per day. At current average US commercial electricity rates ($0.12-$0.15/kWh), the annual difference for a 12-foot run is roughly $1,200-$2,500 depending on store ambient temperature and humidity. Adding night blinds to an open chiller recovers 25-35% of overnight energy but requires staff to pull them every evening.
What temperature range do open multideck chillers hold?
Most open multideck chillers are built for medium-temperature duty: 35 °F to 41 °F (2 °C to 5 °C). They rely on an engineered air curtain that starts to lose effectiveness when the store ambient exceeds 77 °F (25 °C) or when ceiling fans and HVAC vents disturb the curtain. Open freezers (low-temperature, below 0 °F) exist but are uncommon — the energy penalty of an open freezer front is steep, and glass door freezers are the standard in nearly all markets.
Can I add glass doors to an existing open multideck?
Sometimes, but it is rarely a simple bolt-on. The case must be structurally compatible, the refrigeration load changes (door frame heaters add heat inside the cabinet), and the air curtain balance must be re-tuned. Some manufacturers offer retrofit door kits for their own case models. If retrofitting a third-party case, check with the original manufacturer first. For new projects, spec glass doors from the start if that is what you want — it avoids re-engineering and usually costs less than converting later.
Which type holds temperature better during a power outage?
Glass door chillers hold safe temperature noticeably longer because the sealed cabinet functions as an insulated box. Depending on how full the case is and the ambient temperature, product can stay within safe range for 1-3 hours after power loss. An open multideck loses its cold air curtain the moment the fans stop; product temperature begins climbing within 15-30 minutes. Stores in areas with frequent brownouts or unreliable grid power should lean toward glass door cabinets for cold-chain-sensitive categories.
Do open chillers really sell more product than glass door units?
For impulse categories — bottled coffee, single-serve yogurt, chilled snacks, sandwiches — the answer is generally yes. The removal of a door barrier translates to a sales lift of 15-30% in studies of shopper behavior. For planned purchases like gallon milk, bulk butter, and frozen goods, the effect is much smaller — customers walk to that aisle intending to buy, door or no door. The smart layout strategy is to put high-impulse, high-margin items in open multidecks and use glass door cabinets for staples and low-margin bulk goods.
Related reading: For a deeper look at open multideck configurations, shelving options, and temperature specs, see our open multideck chillers page. If you are also evaluating remote vs plug-in refrigeration, visit our commercial refrigeration category for product comparisons.
If you are planning a store build-out or refrigeration upgrade, get in touch for a spec sheet, sample photos, and a project quote matched to your store format and local power conditions. We can help you size the right mix of open and glass door cases so you do not overpay on energy or underserve your merchandising goals.