UK: Refrigerated cabinet door specialist Coolsuredoors, has launched a number of new door solutions that provide not only an improved shopping experience for the customer, but also significant energy savings for the retailer.
“Adding doors to refrigerated retail display cabinets has been proved to deliver increases in energy efficiencies of up to 40 percent,” explains Mike Tucker, managing director of coolsuredoors, "Unfortunately many of the doors on the market restrict the customer’s view of and access to the product. This is something we’ve been very aware of during the design process of the new doors we are now introducing into the market."
Coolsuredoors priorities in the development of the new doors focused on three key areas:
“The customer needs to be able to clearly see what’s on offer and then be able to quickly and safely access product. Both sliding and hinged doors on chiller cabinets come in for some pretty rough treatment from shoppers and we have been very mindful of this in our design and manufacturing processes." explained Mike Tucker, adding, “We have invested heavily in our own R&D test laboratory where we test door components to destruction. This enables us to ensure that the finished article is strong and reliable to stand up to the pounding it will get in the retail environment.”
The new range of doors have been manufactured in acrylic which allows for a frameless solution which gives improved product visibility.
The Universal Door: The coolsuredoors patent pending Universal Door has been specifically designed to offer the best features of both a sliding and a hinged door.
Sliding Doors – Ideal for narrow aisles: The operation of the coolsuredoors sliding only door is identical to the Universal Door when operating in the sliding mode. It is the best solution in stores where the aisle width is limited and a hinged door would obstruct the shopping space.
Hinged Doors – For easy access: coolsuredoors has a range of hinged doors that can be tailored to fit specific applications. Options range from a simple single glass pane design to fully double glazed units.
Acrylic Frameless Double Insulated Doors: Constructed with a frameless design from scratch resistant double-pane acrylic, these doors offer a clear and almost unrestricted view of the merchandise on display. The Clear View Doors are an ideal solution where the isle width permits a hinged door.
The new products sit alongside the already successful Universal door which features Coolsuredoors patent applied for system that allows the doors to be both hinged and sliding in one unit. Offering retailers the best of both worlds, enabling easy access for customers shopping and for staff when restocking or remerchandising cabinets.
For information on the new doors please contact coolsuredoors on 01767 222100, by email on firstname.lastname@example.org. Alternatively you can visit their website www.coolsureldoors.co.uk
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Driven by the European Parliaments new F-Gas regulations Verco have launched their latest innovations in refrigeration technology. Verco's Energy Plus includes a re-designed cabinet to improve airflow along with the fitting of LED lighting, and operating on R407F refrigerant.
Verco is initially introducing the low-energy, high-performance Energy Plus as an option for its Kingston and Verwood models and plans to completely phase out the use of R404a, one of the high GWP HFC refrigerants set to banned under the recent F-Gas regulations review.
Verco's development director Mike Nicholls comments "Following extensive testing, R407F has been selected for its combination of zero ODP (ozone depletion potential) and 53% reduction in GWP (global warming potential) compared to R404a."
Energy Plus is already the standard on the Quebec range of glass-door cabinets – including the single-door Q1XL, two-door Q2CC and three-door Q3CC – Verco has turned its attention to the open-chill Kingston and glass-door Verwood models. Already re-engineered to accept the optional Energy Plus and available to order now are the company's range-topping Kingston K250 (2500mm wide), single-door Verwood V1CHM models. These will be closely followed by the 1950mm wide Kingston K195 and two-door Verwood V2CHM models by this summer.
"Customers specifying the Energy Plus option on Verwood models can expect significant energy savings of up to 33% at chill temperature," says Mike.
Looking to the future, Mike says: "It is becoming increasingly difficult to anticipate and satisfy safety requirements where hydrocarbons are used so, while Verco has committed to standardising on the use of non-flammable refrigerants such as R407f in its glass-door cabinets, we will continue to offer the option of R407f or R1270 on open-chill Kingston and Cambridge models."
For more information on Verco and its Energy Plus Click here
About Verco: Founded in 1965. Verco is now a leading supplier of retail refrigeration and one of the largest UK manufacturers of open-chill and glass-door cabinets.
UK: Cold aisle syndrome is the chilly and often uncomfortable temperature experienced by shoppers in the refrigerated departments of supermarkets and convenience stores. It is caused largely by the spillage of cold air from refrigerated, open front multi deck food display cabinets. Many retailers recognise that cold aisle syndrome can compromise the shopping experience and, during seasonal cold periods, operate costly heating regimes and cold air retrieval systems to temper the chill factor.
Adande claims that its patented Aircell air flow management system significantly reduces cold aisle syndrome, without the need for supplementary HVAC systems. To confirm the existence and extent of the phenomenon, the company commissioned independent research to measure store temperatures within the refrigerated departments of several supermarkets.
Representatives visited the stores of six major UK retailers. At each store, temperature, relative humidity and dew point readings were recorded in a non-refrigerated area to establish ambient conditions. The same measurements were then taken in refrigerated sections of the stores, including dairy, convenience food, produce and pre-packed fresh meat aisles. All data was recorded at a consistent 600mm distance from the refrigerated cabinets, using a USB data logger, with readings taken at 10 second intervals.
Ambient temperatures varied between 16.5oC and 19oC at the six stores visited and cold aisle syndrome was found to exist in all of the refrigerated departments at every store. On average, measurements taken in refrigerated departments were up to 25% - 30% colder than the store ambient temperatures. The extent of cold aisle syndrome was consistently greatest in pre-packed fresh meat aisles, with the most significant temperature discrepancy measured at 11.5oC, some 6.5oC lower than the store’s ambient temperature of 18oC.
Aircell has been designed, amongst other aims, to limit cold aisle syndrome by dividing the cabinet’s merchandising envelope into separate cells between shelves. The smaller cells have a shorter air column and independent management of air movement. The net result is less pressure on the air curtain of each cell and a substantial reduction in cold air spillage from the case. By contrast, conventional open front multi deck cabinets have a single column of cold air from the top to the bottom of the merchandising envelope. As cold denser air sinks, a stacking effect is created and pressure builds at the base of the air curtain. This causes chilled air spillage from the cabinet, creating cold aisle syndrome.
Adande Refrigeration’s Managing Director, Ian Wood, stated:
“Aircell can make a significant difference to customer comfort levels. Its ability to reduce cold air spillage from the multi deck cabinet also has positive implications in terms of energy consumption and temperature stability, without the need to fit glass doors, which are regarded by many as physical barriers to shopping.”
UK: Adande® Refrigeration’s Aircell® technology has been installed for the first time ever at a new Tesco Extra eco store in Lincoln.
Aircell® is a patented airflow management system, designed for open front refrigerated multi deck cabinets. The technology was designed and developed by Adande®, with extensive prototyping, testing, validation and support from refrigeration consultants, ECH Engineering.
The two refrigerated display cabinets were manufactured by Manor Concepts under a licence agreement from Adande®. Manor Concepts incorporated the Aircell® system within its ‘Viper’ remote cabinet design and manufactured the prototype models to a tight deadline.
The Aircell® concept avoids the need to fit physical barriers, such as glass doors, to the front of multi deck cabinets to achieve energy savings.
How it Works: Aircell® segments standard retail cabinets into a series of air flow managed cells with short air curtains. Consequently, there is less pressure on the air curtain of each cell, resulting in a substantial reduction in cold air spillage from the case, so less energy is required to maintain the chilled temperature within the cabinet.
The inherently stable temperature in Aircell® cabinets will also help to maintain the quality and appearance of chilled food over longer periods, reducing the volume of perishable merchandise which may be price discounted or thrown away.
Other features of the 80,000 sq ft Tesco Extra eco store:
Tesco Head of Refrigeration, Joe Gomez, stated: “We view Aircell® technology as a good fit with our environmental and customer focused objectives. It affords shoppers unhindered access to merchandise for ease of shopping. We will be monitoring the cabinets’ energy consumption, product display temperature stability and the effect on cold aisle syndrome against key performance indicators as part of this trial installation.”
Adande® Chairman, Nigel Bell, added: “This installation is an important breakthrough in the evolution of Aircell®. It is the result of hard work and committed cooperation between Adande®, ECH Engineering and Manor Concepts. It also highlights the environmental vision of the Tesco refrigeration and engineering team.”
About Adande: Based in Lowestoft, Suffolk, UK. Applied Design and Engineering (Adande) was founded by Ian Wood and George Young as an HVAC engineering consultancy specialising in industrial ventilation, refrigeration and air conditioning for the offshore oil, gas and petrochemical industries.
Retrofits of refrigeration display cases with glass doors will lead to substantial energy savings, as it is anticipated that when carried out properly there will be a reduction in the overall case heat load by between 50-80% - when compared with open case performance.
Other system improvements such as upgrading to EC fan motors, installing LED energy-efficiency lighting, and raising case evaporating temperatures, can also reduce the heat load from the refrigerated display cases. it is important that the refrigeration system configuration is re-evaluated to match system operation to the load profile.
Improper reconfiguration of refrigeration systems is the predominant cause of case retrofit projects not delivering the expected results. Here, we take a look at some guidelines on how to properly reconfigure and re-commission refrigeration systems after retrofitting open cases with doors.
Let’s take a look…
The first step in properly reconfiguring the refrigeration system should consist of a thorough analysis of the load profile for the cases. Ideally, such system analysis would have been performed as part of the initial engineering assessment in the preplanning phase of the retrofit.
Perform a detailed analysis that accounts for periods of maximum customer traffic and adverse ambient conditions. Maximum heat load estimates will be necessary to ensure that the reconfigured refrigeration system is still capable of delivering the needed cooling capacity under the most extreme conditions that it will encounter so as to ensure product freshness and food safety.
When working with refrigeration systems, it is imperative that refrigerant leaks are prevented. Before any work requiring opening of the refrigeration system, refrigerant should be evacuated from the affected portions of the system. Refrigerant evacuated from the system should be reclaimed and/or recycled as per the appropriate refrigerant handling guidelines and f-gas regulations.
Proper modification of the compressor packs and adjustment of refrigeration system controls constitutes one of the most significant and important aspects of the retrofit process. Installation of doors on open cases, which are traditionally the largest contributors to the refrigeration system heat load, will result in markedly different operating conditions for the compressor packs. Failure to properly re-commission the packs to best match the case loads will result in a mismatch between the load steps of the pack and the actual loads from the cases, resulting in excessive compressor cycling. This mode of operation is much less efficient than the higher-duty cycle operation typically observed when the refrigeration system is matched to the load. Moreover, the added stress of starting and stopping (short-cycling) can lead to excessive wear and tear on compressors, resulting in shortened operational life and additional repair costs.
In addition to performing any necessary modifications to the compressor packs and controls to accommodate the new refrigeration load, the refrigeration contractor should take this opportunity to thoroughly inspect the pack and related equipment for any existing damage or wear and perform the necessary maintenance or repairs to ensure optimum performance. Standard maintenance checks of the compressors, in accordance with the recommendations of the compressor manufacturer, should be performed.
The contractor coordinating the retrofit operation should examine the following areas related to the compressor packs and refrigeration system controls.
In many cases, the decreased load on the compressor pack due to the addition of display doors to open cases will necessitate physical changes to the packs in order to accommodate the modified refrigeration characteristics. Results of calculations of the case heat load under various sets of operating conditions, performed prior to case retrofit operations, should be the key driver for changes to the pack configurations.
In many cases, the reduction in peak heat load seen by the pack will be significant enough to warrant the disabling of one or more compressors on the pack. In this instance, care should be taken to ensure that the pack remains configured in a manner so as to provide appropriate capacity regulation in order to mitigate excessive compressor cycling and product temperature fluctuations. For example, on a pack with differently sized parallel compressors, it may be desirable to disable stages of the larger compressors first, while leaving the smaller ones in place to allow for more load control. Load steps should be compared against anticipated heat load increments, and further compressor changes may be required if the disparity is significant.
In addition to potential reconfiguration of the compressors themselves, additional modifications may need to be made to the following pack components to ensure optimal performance:
• Oil return: Attention should be paid to the suction risers in ensuring proper oil return. If the risers are not properly sized, the rate of lubricant return may be insufficient and damage to the compressors could occur. In many cases, the existing risers will be sufficient. However, the design engineer overseeing the project should verify that this is the case in order to maintain proper performance. If warranted, changes to the risers should be made based on the type of system, depending on whether it has a double riser configuration, or uses an oil separation system. After the retrofit, the contractor should observe oil levels in the separator, reservoir, and/or crankcase to ensure that proper oil return is occurring.
• Refrigerant charge: Charge level should be checked at the receiver and adjusted to ensure agreement between the level of charge and the system’s needs after the retrofit.
• Receivers: Standard maintenance checks should be performed.
After the necessary physical alterations to the compressor packs are made, existing control systems should be recalibrated to ensure proper performance. Controls that should be examined by the commissioning engineer include:
• Variable-frequency drive (VFD) systems;
• Cylinder unloading;
• Building energy management systems (EMS);
• Defrost control systems; and
• Other control systems and schemes.
If the pack is equipped with the capacity to accommodate saturated gas defrosting of coils, the solenoid valve on the main liquid line or the discharge differential valves should be evaluated for compatibility with the new system operating parameters and adjusted or replaced if necessary.
If the pack contains the capacity to perform heat reclaim, calculations should be performed to evaluate the new heat output of the pack when operating in conjunction with the newly retrofitted cases. With reduced heat output, the existing heat reclaim coil could potentially prove to be oversized. If changes to the compressors have been made, this is likely.
The significant decrease in refrigeration load due to the addition of doors on cases has the potential to affect many components of the refrigeration system, including the refrigerant line runs and the case expansion valves. Generally, the existing liquid and suction lines will remain appropriate in size to serve the retrofitted cases. However, attention should be paid to the suction riser in order to ensure adequate refrigerant velocity, and thus proper oil return. The design engineer coordinating the case retrofit should conduct sufficiently detailed system evaluation and flow calculations to ensure that the line sizes utilized will be capable of properly returning a sufficient capacity of refrigerant and lubricant while maintaining the desired properties.
Expansion valves attached to each individual coil in the display cases serve the critical function of controlling coil superheat, and will require changes to accommodate the markedly different refrigerant flow properties precipitated by the change in the case configuration during the retrofit. For expansion valves with removable orifices, a compatible orifice properly sized for the new refrigerant flow level may be available. In other instances, expansion valves will need to be replaced altogether. During system analysis and modelling, the design engineer should analyse the anticipated heat loads and refrigerant flow conditions, and choose properly sized valves for each display case accordingly. It is anticipated that expansion valves will likely need to be reduced one or two sizes to ensure correct superheat control at reduced refrigerant flow rates and increased evaporator temperatures.
If electronic expansion valves are in place, generally the valves will not need to be altered. However, the valve manufacturer’s literature should be reviewed in order to ensure the valves’ compatibility with the new system configuration.
Additionally, each case line-up contains a solenoid valve or evaporator pressure regulator (EPR if fitted) used to control case temperature. Solenoid valves used in either the liquid or suction lines can generally be retained, provided that the sizing of the lines is evaluated as described above to ensure a proper operating pressure across the valve. However, due to the fact that the reduction in load created by the retrofit allows for higher case suction temperatures, an EPR is preferred for optimal performance. Existing EPRs should be checked for proper performance at the new case loads. If possible, the common suction temperature downstream of the EPR should be raised in order to further reduce the power input requirement at the compressor rack.
Supermarket refrigeration systems generally use separate air-cooled condensers, most often located on the rooftop of the building, to reject heat to the ambient environment. In many cases, excess condenser capacity will already be accounted for by existing control and operation schemes. However, in some instances, removal of excess condenser capacity may be warranted. Additionally, operators in climates experiencing extreme winter cold or high summer temperatures should consider climatic factors when making modifications to their condensers.
The discharge riser (the piping from the compressor rack outlet to the condenser) should be evaluated for proper sizing based upon the new system operating parameters. In many cases, the existing sizing will be adequate. However, if the retrofits were significant enough to create a sufficient impact on the given system, the line may need to be resized in order to ensure sufficient lubricant return to the compressor pack.
Condensers equipped with a head pressure control device, which regulates the head pressure to prevent it from falling below optimal condensing pressure during low ambient temperature conditions should be checked and resized if necessary.
If the condenser features subcooling and the drop in case heat load is sufficient, the subcooler and the associated expansion valves may need to be resized.
In systems featuring condensing units, with a single display case being served by a dedicated remote condensing unit, the issue of load reduction is likely to have a more pronounced impact than in multiplex pack systems. This is due to the fact that the single condensing unit operates on demand based solely on the conditions in the case served, and is originally sized to the anticipated load of the case. Whereas a pack system often can be modified in a fairly straightforward manner to accommodate lower case loads (such as through disconnecting a compressor or adjusting existing controls), this may not be possible using the existing equipment in a dedicated remote-condensing unit. If the unit is left to run as is with a case load that is 50 percent or more below that for which it was originally designed, the condensing unit will be grossly oversized, and the result will be frequent compressor cycling. This will result in highly inefficient operation due to the high number of compressor and condenser fan starts and stops, as well as possible shortening of refrigerated product lifetime due to rapid warming and cooling cycles.
In light of the resulting discrepancy between case heat load and condensing unit capacity after a retrofit, one of two measures could be employed in order to bring the two values closer together. The first of these would be the employment of a suction line crankcase regulator or similar control device to hold the refrigerant flow so that the condensing unit experiences a reduced impact due to the decrease in load. However, since this step enables the condensing unit to operate in a manner similar to which it did with an open case, this means that the full energy savings will not be realized. Another measure, if feasible based on the physical size and location of the cases, is the consolidation of multiple cases onto single condensing units. In this instance, a condensing unit that was originally sized to operate a single display case could be reconfigured to serve two cases through rerouting of refrigerant piping and other adjustments. Proper calculations should be carried out in order to ensure that the existing condensing unit is capable of accommodating the peak loads of multiple cases.
Retrofit operations, by design, have the intended result of significantly changing the electrical demand profiles of the display cases and refrigeration systems. Case electrical consumption may be reduced due to changes in lighting and fan power, while a compressor pack reconfigured for retrofitted cases may use, even in peak operation, far less electricity than it previously needed. While this is desirable from an energy-efficiency and cost-reduction standpoint, care must be taken to ensure that the building electrical system is still correctly sized for the refrigeration equipment per the relevant building regulations and safety codes. For example, existing circuit breakers may be grossly oversized and may not trip even in the case of an overload situation, which could present a serious safety hazard. A qualified engineer should be consulted to ensure that all building codes and electrical safety requirements are met, and that the building electricity supply and connections are properly sized for the new operating profile of the system. Display cases and refrigeration systems are generally labelled in a manner that reflects the necessary certification of the equipment. Changes to the physical composition of the cases by way of component swaps and additions, as well as changes to the case electrical system, would likely require recertification with these bodies. Similarly, any changes to the components of the pack may require recertification.
Any work to the sealed portion of the refrigeration system will have required evacuation of the refrigerant in the system previous to the modifications being performed. Prior to restarting the system, the commissioning engineer should ensure that the areas of the system that have been evacuated are properly recharged to the necessary levels using the appropriate refrigerant. Particular attention should be paid to any system modifications that could result in a change in the required refrigerant charge. For example, due to the load reductions on the system, each case’s evaporator coil may require an increased charge, resulting in a need to add more refrigerant to the entirety of the system before it is returned to service.
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