ClassX Video Lessons Youtube Channel The Engineering Mindset Supermarket HVAC Basics Explained – Refrigeration / Ventilation hvac building services
Welcome to an insightful exploration of the HVAC systems commonly found in supermarkets and food retailers. This article aims to provide a clear understanding of how these systems function and integrate to ensure the building operates efficiently.
As you enter a supermarket, you might notice a blast of air at the entrance. This is the air curtain, a crucial component designed to create a barrier between the indoor and outdoor environments. Positioned above doorways or integrated into the ceiling, air curtains use a blower fan to generate a powerful air jet. They can be equipped to provide heated or cooled air, utilizing either a heat exchanger or an electrical heating element. By minimizing the exchange of indoor and outdoor air, air curtains help maintain indoor air quality and prevent dust, dirt, and insects from entering the store.
Supermarkets often feature extensive ductwork suspended from the ceiling, part of a forced ventilation system. These ducts are connected to either air handling units or rooftop units, with the latter being more prevalent due to their all-in-one HVAC capabilities. Rooftop units, located on the store’s roof, draw in fresh air and distribute it throughout the building, while also expelling used air after filtering it. Air handling units, typically larger and housed indoors, perform similar functions and can recirculate air if it meets specific CO2, humidity, and temperature criteria.
In larger stores, you may observe fan coil units connected to short duct runs. These units contain a fan, filter, and heat exchangers, circulating air locally to provide additional heating or cooling. They can be connected to various systems, including heat pumps, VRF systems, split ACs, chillers, or boilers, to ensure optimal indoor climate conditions.
To manage odors from restrooms and food preparation areas, supermarkets employ dedicated exhaust systems. Centrifugal fans, a common choice, create a pressure difference to effectively extract and expel air, maintaining a pleasant indoor environment.
For staff areas or smaller stores, gas boiler systems are often used for space heating, especially in Europe. These systems circulate heated water through radiators or trench heaters. Refrigeration systems can also provide heating and cooling, utilizing VRF, split AC, and heat pump technologies. VRF systems, in particular, offer flexibility by adjusting refrigerant flow to match cooling demands, allowing simultaneous cooling in multiple locations.
Cold storage areas in supermarkets rely on refrigeration systems with external condensers and compressors to remove unwanted heat from stored food. Display refrigerators on the shop floor often use compact vapor compression systems, while larger units may employ external components for greater efficiency. Centralized refrigeration systems, common in larger stores, manage refrigerant flow using booster or parallel configurations.
A notable trend in supermarket refrigeration is the adoption of transcritical CO2 systems, which enhance efficiency and adaptability across different climates. Cascade systems are also gaining traction in larger stores and industrial sites, offering robust solutions for complex refrigeration needs.
For more insights into the evolving world of supermarket HVAC systems, explore additional resources and stay informed about the latest technological advancements.
Imagine you are tasked with designing an HVAC system for a new supermarket. Consider the different components discussed in the article, such as air curtains, ventilation systems, and refrigeration units. Create a detailed plan that outlines where each component will be placed and how they will work together to ensure efficient operation. Present your design to the class, explaining your choices and how they contribute to maintaining the supermarket’s environment.
Research a real-world supermarket and analyze its HVAC system. Identify the types of systems they use for ventilation, heating, cooling, and refrigeration. Discuss how these systems integrate to maintain air quality and food preservation. Share your findings in a report, highlighting any innovative technologies they employ and how these could be applied to other supermarkets.
Participate in a workshop where you will troubleshoot common issues that arise in supermarket HVAC systems. Work in groups to diagnose problems such as inefficient air curtains, ventilation blockages, or refrigeration failures. Develop solutions and present your approach to resolving these issues, considering both technical and cost-effective strategies.
Engage with an interactive simulation that models the operation of a supermarket HVAC system. Experiment with different settings for air curtains, ventilation, and refrigeration to see how they affect the overall environment. Use the simulation to understand the impact of various factors such as outdoor temperature and store layout on system performance. Share your insights with the class.
Lead a discussion on the future trends in supermarket HVAC systems, focusing on the adoption of transcritical CO2 systems and cascade systems. Explore how these technologies improve efficiency and adaptability. Debate the potential challenges and benefits of implementing these systems in different climates and store sizes. Conclude with a group consensus on the most promising trends for the future.
Sure! Here’s a sanitized version of the provided YouTube transcript:
—
[Applause] Hello everyone, this is [Name] from The Engineering Mindset. In this video, we will explore the various HVAC systems found in typical supermarkets and food retailers. Our goal is to understand the basics of how each system works and how they are integrated to make the building functional.
You can learn more about how technology is making supermarkets smarter, safer, and more environmentally friendly by downloading the free Smart Store ebook by Danfoss, who kindly sponsored this video. The ebook outlines five trends shaping the food retail industry and practical steps to stay ahead. Links can be found in the video description below.
The first thing we usually notice when entering a store is the air curtain. This is the blast of air you feel when you enter the building. In larger stores, air curtains may also be used in loading bays. The air curtain is typically suspended above the doorway or built into the ceiling. Inside the unit is a blower fan driven by a small electric motor, which forces air into a funnel to create a powerful jet. Versions are available that provide heated and/or cooled air. For heating, a thin tube heat exchanger is common, but an electrical heating element can also be used. For cooling, a heat pump can be employed, utilizing refrigerant to adjust the air temperature based on the season. Additionally, this can be integrated into a VRF heat recovery system to provide heating and cooling to different parts of the store simultaneously, which we will discuss in more detail later.
So, why do we use air curtains? They create a barrier between indoor and outdoor air, which typically have different temperatures and humidity levels. Stores invest significantly in maintaining indoor air quality, so we want to minimize the loss of conditioned air and prevent outside air from entering. Air curtains help reduce this mixing and also keep dust, dirt, and insects from entering the store.
Next, we notice the forced ventilation throughout the store. In many large supermarkets, ductwork is suspended from the ceiling. The ducts come from either air handling units or rooftop units, both serving similar roles. Rooftop units are more common in supermarkets as they provide an all-in-one HVAC solution. These units are located on the roof and usually come in multiples, depending on the store size. Inside, a large fan pulls fresh air into the unit and pushes it into the building. Some units also push out used air, passing it through filters to remove dust and dirt before heating or cooling it to meet required conditions.
Air handling units work similarly but are typically larger and housed indoors. They filter, heat, cool, and humidify the air, with heating and cooling provided by remotely connected chillers or boilers. These units also maintain pressure in the building and extract used air. If the returning air meets certain CO2, humidity, and temperature limits, some can be recirculated to reduce the heating or cooling load.
If you look up in large stores, you might see a fan coil unit connected to a short duct run. Inside, it contains a fan, a filter, and one or two heat exchangers. The fan coil circulates air locally and supplements heating or cooling as needed, also helping to distribute fresh air within the building. Fan coil units can provide heating and/or cooling, with heat exchangers connected to heat pumps, VRF systems, split ACs, chillers, or boilers.
We also need to address odors generated in the building from areas like restrooms and food preparation zones. This air must be extracted, often through dedicated exhaust systems. Various fan types are used, with centrifugal fans being one of the most common designs. These fans create a pressure difference to pull air in and push it out.
For space heating and cooling in staff areas or smaller stores, gas boiler systems may be used, providing heat through radiators and trench heaters, especially in Europe. A basic system includes a circulation pump that moves water around a closed system, picking up heat from the gas-fired boiler and delivering it to the radiators.
Refrigeration systems can also provide space heating and cooling, utilizing systems such as VRF, split AC, and heat pumps. Split AC systems are simple vapor compression systems that use a compressor, condenser, expansion valve, and evaporator to collect unwanted heat and provide cooling.
The VRF (Variable Refrigerant Flow) system uses a variable speed compressor and electronic controls to match refrigerant flow to the cooling load, allowing simultaneous cooling in multiple locations. Heat pumps can switch between heating and cooling but can only provide one at a time by utilizing a reversing valve.
A common system is the VRF heat recovery system, which provides both heating and cooling simultaneously to different parts of the building. In cooling mode, it absorbs heat from indoors and dissipates it outside. In heating mode, it collects thermal energy from the outside air and transfers it indoors.
Regarding food storage, most supermarkets will have cold storage areas that vary in size. These use refrigeration systems with externally located condensers and compressors to extract unwanted heat from the food and dissipate it into the atmosphere.
On the shop floor, display refrigerators typically have compact vapor compression refrigeration systems installed under the unit. Larger refrigerators may use external condensers and compressors, which are more efficient as they remove heat from the refrigerator and the space. Centralized refrigeration systems are common in larger stores, utilizing booster or parallel systems to manage refrigerant flow.
A growing trend is the use of transcritical CO2 refrigeration systems, which can improve efficiency and adaptability to different climates. Cascade systems may also be used in larger stores or industrial sites.
That’s it for this video! For continued learning, check out one of the videos on screen now. Don’t forget to like, subscribe, and follow us on social media, as well as visit The Engineering Mindset website.
—
This version removes any informal language and maintains a professional tone while conveying the same information.
HVAC – Heating, Ventilation, and Air Conditioning, a system used to regulate the environmental comfort in buildings – The HVAC system in the new office building was designed to maximize energy efficiency while maintaining optimal indoor air quality.
Ventilation – The process of supplying fresh air to and removing stale air from an indoor space – Proper ventilation is crucial in laboratories to ensure that hazardous fumes are effectively expelled.
Refrigeration – The process of removing heat from a space or substance to lower its temperature – The refrigeration unit in the data center is essential to prevent overheating of the servers.
Air – The invisible gaseous substance surrounding the earth, a mixture mainly of oxygen and nitrogen – Engineers must consider air flow dynamics when designing ventilation systems for high-rise buildings.
Systems – Interconnected components that work together to perform a specific function – The integration of renewable energy sources into building systems can significantly reduce carbon emissions.
Cooling – The process of lowering the temperature of a space or substance – Effective cooling solutions are critical in maintaining the performance of industrial machinery.
Heating – The process of raising the temperature of a space or substance – The new heating system utilizes geothermal energy to provide sustainable warmth to the facility.
Quality – The standard of something as measured against other things of a similar kind – Air quality sensors are installed throughout the building to monitor and ensure a healthy indoor environment.
Climate – The long-term pattern of weather conditions in a particular area – Engineers must design infrastructure that can withstand the impacts of changing climate conditions.
Efficiency – The ability to accomplish a job with a minimum expenditure of time and effort – Improving the energy efficiency of HVAC systems can lead to significant cost savings and reduced environmental impact.
