What is an ASRS in a Cold Storage Warehouse?

An ASRS (Automated Storage and Retrieval System) is a warehouse technology designed to store and retrieve inventory using automation. ASRS technology is used in cold storage warehouses globally and increasing every year in North America. An automated cold storage facility allows for higher density of storage, greater pallet position height, reduced labor costs and risks, 24/7 operation, and a smaller building footprint.

ASRS cold storage warehouse buildings are built taller and more compact compared to traditional cold storage buildings that required forklifts to retrieve product. Selecting the right industrial air cooler (evaporator) is vital for ensuring proper air flow, maximum storage space, serviceability, and equipment that fits the footprint of the automated cold storage refrigerated warehouse. There are several configuration and design options for selecting industrial air coolers for an ASRS refrigerated warehouse. Each air cooler configuration has its own set of advantages and disadvantages.

Industrial Air Cooler Configurations for ASRS Cold Storage Warehouses

1.      Insulated penthouse air coolers mounted outside of the building envelope.

2.      Penthouse air coolers installed inside the building envelope.

3.      Ceiling hung industrial air coolers.

4.      Rack-mounted industrial air coolers.

Insulated Penthouse Air Coolers Mounted Outside of The Cold Storage Building Envelope

Fully fabricated from the factory, insulated penthouse air coolers allow for installation outside of the building envelope. The air coolers are fully enclosed in an insulated enclosure that acts as a vapor barrier, then ducting is connected to disperse the air through the cold storage space. Different insulated penthouse configurations are available to install the air cooler on the roof, the dock, or the ground level. Mounting the air cooler outside of the cold storage building in an insulated penthouse configuration presents several benefits:

• Increased Maintenance Safety: Eliminates the need for maintenance personnel to access high ceiling hung evaporators through lifts, increasing safety while accessing the insulated penthouse.
• Reducing Refrigerant Hazard: By relocating the evaporator away from the workspace, potential human exposure to refrigerant hazards is minimized.
• Optimized Storage Space: Freeing up internal space allows for greater cold storage capacity, allowing taller pallet racks within high-bay automated warehouses.
• Cold Storage Building Design flexibility: Insulated penthouse evaporators can be installed at the ground level with ducted airflow to the top of the pallet positions, installed on top of the dock roof, installed on the roof of the cold storage building. These different insulated penthouse configurations provide the end user and system designer with different building design options.
• Box in a Box Cold Storage Construction: Insulated penthouse air coolers can be made compatible to box in a box style ASRS cold storage buildings. This is done by insulating the base of the insulated penthouse unit, then ducting to the side of the insulated enclosure.
• Enhanced Defrost Cycle: Compared to ceiling-hung air units, insulated penthouse air units minimized the required time to achieve melt, minimizes convection load back to space, and minimizes re-evaporation to space.  

The Colmac Coil A+Series® A+P Roof Mounted Insulated Penthouse Air Cooler is a fully insulated penthouse air cooler for industrial applications. The A+P is available in several customizable configurations including dual coil, insulated base, and pitched base. The dual coil configuration provides large capacities while increasing system redundancy by allowing sequential defrost. Insulated base Configurations give the capability of installing the air unit off the cold storage roof or for buildings with an interstitial space (box in a box cold storage facilities). The pitched base on the base of the air unit option reduces the need for a separate curb. All these design options are available in Colmac Coil A+Pro Selection Software.

Penthouse Air Coolers Installed Inside the Cooled Space

Air Coolers can be installed in a field erected penthouse room in the interior of the cold storage building envelope. Installing the air coolers in a traditional penthouse room could be appealing for several reasons:

• Lower Install Costs: There could be cost savings to install the air coolers in a field erected penthouse room. Various contractors install their own insulated wall panels, allowing for a lower cost field erected penthouse compared to a factory built insulated penthouse air cooler.
• Easier Maintenance Access: It is common for several large air coolers to be installed in one field erected penthouse room, thus allowing easier access for servicing the air coolers from one central location inside of the building envelope.

Colmac Coil manufacturers A+Series® A+L Penthouse Industrial Air Coolers for field erected penthouse rooms in cold storage facilities. This A+L configuration is equipped with 90 degree down air duct extensions to connect to the air distribution plenums. As an option available from Colmac Coil in A+Pro Selection Software, return air hoods can be included on this configuration to enhance the defrost cycle.

Ceiling Hung Industrial Air Coolers

ceiling-hung evaporators can be a practical and efficient choice for contractors when designing and installing refrigeration systems in ASRS cold storage facilities. Ceiling hung air unit advantages installed in a cold storage facility:

• Air Cooler Placement: Depending on the design of the cold storage, an air cooler can be mounted in the aisle ways, above the pallet positions, or multiple air cooler units stacked vertically through the aisles.
• Less Equipment Weight: Ceiling hung air coolers typically weigh less than penthouse air coolers and insulated penthouse air coolers. Depending on the design of the cold storage building and weight-load limitations, ceiling hung evaporators could be the best solution.

Disadvantages of ceiling-hung air units installed in a cold storage facility:

• More prone to damage: Ceiling hung evaporators are more prone to being damaged during installation or servicing because of the required use of a scissor or forklift.

The A+Series® A+L and A+M ceiling hung air coolers provide many design options to improve the defrost cycle, standard industrial construction for long equipment life, and are standard with EC fan motors. EC fan motors provide high efficiency, large airflow capacities, are very reliable, and have inherent fan motor speed control. Colmac A+Series® Air Coolers offer the most advanced and innovative features in the industry for ASRS cold storage facilities.

Rack-mounted Industrial Air Coolers

Industrial air coolers can be designed to be installed along the aisle ways of the pallet positions, mounted on the rack ends. This configuration can allow more airflow along the height of the products of different pallet positions. A few vendors offer an air cooler that’s installed on the pallet rack, which turns the pallet system into a blast freezer. The rack mounted industrial air cooler configuration can provide closer contact to the cooled product and the ability to stack a series of air coolers vertically.

Colmac Coil has provided industrial air coolers for several ASRS projects in this configuration. The Refrigeration Load Simulator application, available from Colmac Coil, accurately models and predicts the refrigeration load for an entire facility.

Air Cooler Design Considerations

• Air throw requirements and equipment layout for air distribution
• Cooling system type
• Cooled product type
• Building envelope and structural integrity requirements of the building roof
• Serviceability access
• Retrofit vs. new project

With our ability to accurately predict the performance of our heat exchangers, design to fit your footprint, and build with a wide variety of materials, we welcome the opportunity to partner with you to find a creative and efficient heat transfer solution for your process or products. Please do not hesitate to contact the factory or your local Colmac Coil Representative if you have questions, would like to sign up for Colmac Coil’s selection software or have specific project requirements.