Store HVAC Design with Open Multideck Refrigerators: Balancing Temperature and Energy

Store HVAC design: the missing key to efficiency in the era of open multideck refrigeration

Success for a modern hypermarket or supermarket no longer depends only on product range and pricing. Customer comfort and energy productivity are two pillars of sustainable profitability in retail today. Between those factors sits a hidden hero that is often overlooked: store HVAC system design. An efficient air-conditioning system does more than cool or heat the space—it manages air quality, controls humidity, and creates a pleasant shopping environment.

Until a few years ago, store ventilation followed a fairly standard formula. The arrival of a new generation of retail store equipment has rewritten those equations. On the front line of that shift are open multideck refrigerators — also called doorless refrigerated displays. By removing glass doors, these units enable easy grab-and-go access and striking product visibility, and they have significantly lifted sales. But this innovation creates a complex, fascinating engineering challenge for HVAC designers.

This article is a specialist guide for retail managers and investors who want to know how to design a smart ventilation system that does not "fight" open multideck units but synergizes with them. Understanding that delicate balance is the difference between a costly store with punishing energy use and an efficient, profitable one. We answer a vital question: how do you keep temperature and energy in perfect balance in a store equipped with doorless refrigeration?

How does an open multideck refrigerator work, and why does it challenge HVAC design?

Before we can review ventilation solutions, we need to understand exactly how an open multideck refrigerator affects the store's physical environment. These units—the backbone of fresh food in modern hypermarkets—are a masterpiece of thermodynamic engineering.

Unlike traditional cabinets, they use a cold, dense stream of air—the —instead of a physical door. A fan at the top of the opening and along the rear wall drives a uniform downward flow at a calculated velocity. Before it can escape, that air is drawn in through a grille at the bottom, passes again over cold evaporator coils, and returns to the loop.

This "invisible curtain" separates two environments: very cold air inside the cabinet (for example 2 to 4 °C) and ambient store air (for example 22 to 24 °C). But the curtain is not a brick wall; it is fragile and highly sensitive to surrounding conditions. That is exactly where interaction with the store HVAC system becomes critical.

A precise grasp of these interactions and physical challenges is the main key to an efficient engineering solution. Before we move to remedies, we should examine in full the three main technical challenges these cabinets pose to ventilation—and in later sections we cover detailed, integrated answers.

1. Latent load challenge: the battle with humidity

The biggest challenge is not temperature but humidity. Store air—moistened by customer breathing and outdoor infiltration—carries water vapor. Even a gentle ambient airflow can push some of that moist air into the cold . When that moisture hits evaporator coils (well below freezing), it freezes instantly and forms frost. That phenomenon is called latent load.

Frost acts like thick thermal insulation, blocks heat transfer, and sharply cuts cabinet efficiency. The refrigeration system must then enter frequent defrost cycles to melt that ice—often with electric heaters. Those cycles consume a great deal of energy and temporarily raise internal cabinet temperature, shocking product. So ventilation that does not control ambient humidity can multiply energy use of refrigerated display cabinets.

2. Sensible load challenge: cold spill and cold aisle syndrome

Cold air is denser (heavier). Despite careful engineering, some cold air from the curtain inevitably spills onto the floor of the aisle in front. That creates two problems:

• Cold aisle syndrome: cold air pooling at floor level makes shoppers feel uncomfortable chill at their feet in that zone.
• Thermodynamic conflict: store HVAC set for about 22 °C treats that spilled cold floor air as a temperature drop. The thermostat commands more heating to compensate. Ventilation and refrigeration end up in a direct, wasteful fight—canceling each other and burning enormous energy.

3. Turbulence challenge: breaking the

The most sensitive factor is air turbulence. The refrigerator is designed for a calm environment. Any fast external draft can "tear" the curtain. Where does that airflow come from? Often the store HVAC system itself. If supply grilles sit directly above multideck aisles or blow at high velocity toward them, you systematically destroy the curtain and pour warm, moist air into the cabinet.

These three challenges show that store HVAC design for stores with open multideck refrigerators is not a standard template but a precise engineering answer—a controlled, calm micro-climate.

Fundamental principles for store HVAC with open multideck refrigeration

With the nature of the problem clear, we can turn to engineering solutions. Successful HVAC design for a modern hypermarket rests on four principles, all aimed at synergy between HVAC and refrigeration.

Principle 1: Active humidity management (dehumidification)

As noted, humidity (latent load) is the number-one enemy of refrigerator and open multideck freezer efficiency. Standard air conditioning is built mainly for temperature (sensible load); dehumidification is a side effect of cooling. That is not enough.

The problem peaks in spring or autumn when air is cool but humid (for example a rainy day). AC may not run because temperature is fine, yet high humidity enters the store, is absorbed by the cabinets, and drives heavy frost. (Open multideck units have defrost systems, but energy use rises.)

Solution:

• Dedicated dehumidification systems: standalone units (such as desiccant systems) that can remove moisture without necessarily changing air temperature.
• HVAC with reheat capability: advanced packages that over-cool air to strip moisture, then use a heat source (such as recovered condenser heat) to bring supply air back to comfort temperature.

Keeping store relative humidity in a controlled band (typically below 55%) can dramatically cut refrigerator energy use.

Principle 2: Low-velocity air distribution

This is the most critical technical rule for preventing curtain failure. Grille location and type directly affect multideck performance.

Golden rule: never blow supply air directly at the open face of an open multideck refrigerator.

High-velocity flow—even at the right temperature—creates turbulence and drives ambient air into the cabinet.

Solution:

• Low-velocity diffusers: instead of standard grilles that "throw" air downward fast, use diffusers that spread air gently over a wide area.
• Strategic grille placement: locate supplies in the center of aisles (away from cabinets) or in adjacent aisles so airflow slows and mixes with room air before it reaches multidecks.
• Displacement ventilation: an advanced approach where fresh, conditioned air enters slowly from low-level grilles. It rises naturally as it picks up heat from people and lighting and exhausts at the ceiling—creating the calmest, least turbulent environment possible.

Principle 3: Zoning for precise control

Your whole store does not have one temperature—and should not. The open multideck aisle, because of cold spill, is its own micro-climate. Treating it like dry grocery or checkout aisles is a major mistake.

Solution:

Smart design divides the store into zones. The fresh-food aisle (including open multideck units) should be a separate zone with its own thermostat and controls. HVAC can then add gentle heating only when needed—often from the floor or at low velocity—to keep shoppers comfortable without fighting the cabinets or overheating other aisles.

Principle 4: Integrated load calculation

In traditional projects, refrigeration and HVAC contractors work separately. HVAC treats cabinets as a simple added heat load. That view is incomplete. An open multideck unit simultaneously adds heat (from motors and condensers on self-contained models) and cold (spill) to the space and removes moisture.

Solution:

Load calculations must be integrated. The HVAC designer needs exact cabinet models, specs, and locations. Latent load removed by refrigeration should be credited against building latent load; sensible load (cold spill and heat rejection) must be modeled carefully in HVAC sizing. That requires close cooperation between design teams.

On open multideck lines with remote refrigeration plants, compressor heat is rejected outside the sales area and does not heat the store; on self-contained multidecks, motor heat returns to the shop floor. Integrated load and system design are therefore essential.

Advanced techniques for maximum optimization: beyond standard ventilation

Following the fundamentals ensures correct operation. For exceptional energy performance and a truly sustainable store, engineers adopt technologies that turn HVAC and refrigeration into one coordinated orchestra.

1. Heat recovery systems

Refrigeration (cabinets and freezers) is effectively heat pumping: heat moves from product to condensers outdoors. In a large hypermarket, rejected heat can be tens of kilowatts—often wasted to ambient air.

Solution: heat recovery captures that energy:

• Domestic hot water (DHW): the simplest, common use—free heat for restrooms, kitchen, and food-prep areas, often eliminating water-heating cost.
• Reheat for dehumidification: as in Principle 1, use recovered heat to warm overcooled, dehumidified supply air.
• Space heating in winter: instead of dumping heat outside, route it to HVAC to support store heating and cut gas or electric heating bills.

2. Building management system (BMS)

The building management system is the store's control brain—a central platform linking HVAC, refrigeration, lighting, and security.

For our topic, BMS:

• Coordinates subsystems: when cabinets enter defrost (adding heat), BMS can temporarily adjust zone ventilation to limit temperature swings.
• Floating control: instead of fixed setpoints, BMS can adjust dynamically for peak shopping hours, electricity pricing, or even weather forecasts.

Without BMS, separate systems at best ignore each other and at worst fight. With BMS, you have one integrated, optimized plant.

3. Entrance s

Just as cabinets use an for protection, the store must protect the whole sales floor from outdoor infiltration. Entrance doors—especially on high-traffic stores—are a major path for hot, humid summer air and cold winter air.

Powerful, well-designed entrance s form an air barrier that minimizes uncontrolled exchange between inside and outside. That lowers load on the store HVAC system and helps stabilize conditions for open multideck refrigerators.

Behsarma's vital role: from integrated design to end-to-end store launch

As we have shown, solving store ventilation alongside open multideck refrigeration is a complex, multi-faceted engineering puzzle. The answer is not buying a more expensive HVAC package or a better cabinet alone—it lies in integration of refrigeration and air-conditioning knowledge.

That is where expertise makes the difference between a costly, inefficient store and a profitable, optimized one. At Behsarma, we treat this challenge not as a problem but as an opportunity for smart engineering.

Behsarma's dedicated hypermarket and supermarket design and launch unit exists for exactly these challenges. We understand that refrigerators, gondola shelving, checkout counters, and HVAC are not isolated islands—they are sections of one orchestra that needs an experienced conductor.

Behsarma's broad experience equipping and launching stores—from large chain hypermarkets and premium supermarkets to specialist protein shops—plus cooperation with leading domestic brands and export to neighboring countries, gives us unique insight into custom equipment and precise engineering solutions.

Our approach is comprehensive:

1. Design-first: before the first brick, our store design consulting team optimizes layout for fluid dynamics, airflow, cabinet placement, and HVAC grille locations.
2. Equipment as a system: we help you choose retail store equipment (such as open multideck refrigerators) that excels not only in aesthetics and performance but in harmony with the proposed ventilation strategy.
3. Integrated execution: in store setup consulting, we ensure HVAC and refrigeration contractors work from one coordinated plan—avoiding common mistakes and thermodynamic "wars."

In the end, temperature and energy balance in your store requires a designer who deeply understands cold cabinet air and warm ambient air. That knowledge is one of Behsarma's core specialties.

Conclusion: investing in smart ventilation protects open multideck performance

Open multideck refrigerators are outstanding sales tools and symbols of a modern store. Their full potential appears only in an engineered environment. Investing in integrated, intelligent store HVAC design is not an extra cost—it directly attacks your largest operating expense: energy. It extends life of costly assets (cabinets and compressors), preserves product quality (less waste), and improves customer experience (more sales).

Do not let capital vanish in a pointless war between ventilation and your refrigerated display cabinets. With integrated design, let both systems work in full harmony for your success.

Behsarma specialists are ready to support you with a comprehensive, integrated approach from initial design through full launch. Contact us today for free expert advice on optimizing store ventilation and choosing the right retail store equipment for your needs. Let's build an efficient, sustainable, profitable store together.