Energy Management

How to Reduce and Conserve Energy in Refrigerated Spaces

Refrigerated spaces used in the food and beverage industry have several systems that should be considered for energy efficiency and conservation. Note that the Steve Hot Wattmost financially economical models of energy projects include combining efficiency and conservation (controls). The key to compounded savings is that they drive custom utility incentives in many cases. The net result is typically a 25-50% incentive, which can make an energy project payback an incredible investment.

Although the largest portion of the energy consumed is for the refrigeration equipment, here are Top 3 areas that should be considered to have the greatest impact on the reduction of energy consumption and what to do to reduce.

1. Evaporators fan replacement and controls. Two-speed and variable-speed EC motor replacement with ECM controls. Pre- and post-measurement and verification has proven actual average savings of 70% of the operating cost of the evaporator fan motors in refrigerated spaces. The replacement of standard single-phase shaded-pole, permanent split capacitor or small 3-phase motors with electronically commutated motors results in a significant savings. Controls read the flow of refrigerants, places the fan motors on low speed while the compressor is not in use and slowly ramps them up to high speed during compressor duty cycle (a duty cycle is typically 40% of a 24-hour day). Using multiple speed motors and ECM controls combines efficiency and conservation for remarkable compounded savings.

2. Lighting changes from HID and fluorescent. LED lighting uses less than 75% of the energy of HID lighting and can be used in conjunction with motion sensors to reduce lighting energy costs over 90%. Since T-12 fluorescent technology has been mostly legislated out of production, the most economical switch can be to retrofit with T8 technology and electronic ballasts or replace with LED. A replacement from metal halide or high-pressure sodium (HID) to LED Luminaires in a refrigerated space offers not only a significant watt-for-watt reduction, but also emits up to 70% less heat than an HID, which means compressor run times are significantly reduced.

3. Improving forklift battery charging systems. Upgrading battery chargers to the newest technologies will improve charging times and cycles, and battery management with power conversion efficiencies of 61% to 92%.

After the first three areas have been considered, the following list offers smaller reductions specifically for the refrigeration system to achieve ultimate energy efficiency.

• Reduce minimum condensing pressure. For example from 100 psig to 90 psig, annual average savings of 3%.

• Reduce defrost condensing pressure. For example, from 120 psig to 110 psig, average annual savings of 3%.

• Night and weekend suction pressure setback. Increasing the suction pressure from -33°F to -28°F, average annual savings is 4%.

• Condenser fan staging and controls. For example, run only condenser pumps and fans together and control the condenser fan speed. Once the condenser fan reaches 50%, turn on one more fan at 50%, average annual savings is 5-10%.

• Regular condenser and non?condensable check. Create a written process for checking condenser energy performance on a bi-annual basis to bring the units back to spec and avoid faults like auto-purger drift. Average annual savings could be in the 5% range.

• Regular compressor check. Create a written process for checking compressor energy performance on a bi-annual basis to bring the units back to spec and avoid faults like set point drift, slide valve calibration, oil cooler settings and economizer operation. Annual average savings could be in the 5% range.

• Test for water in ammonia charge. Create a written process for annually checking ammonia water levels, which needs to be extracted to improve performance. For example, a 10% water level could cause a 7% inefficiency in the system.

• Switch to non?clogging condenser nozzles. Test condensers for water flow ability of current nozzles and replace if they are clogged. A 30% clog results in fans working 15% harder. Replacements in this scenario could result in a 10% savings.

• Switch to notched condenser fan belts. Replace regular belts with V-notch style, which create less friction and have an average annual savings of 2%.

Did you enjoy this article? Click here to subscribe to Refrigerated & Frozen Foods magazine.

You must login or register in order to post a comment.

Multimedia

Videos

Image Galleries

Evolution Fresh: Enhancing the Premium Juice Market with HPP Technology

Evolution Fresh’s new Rancho Cucamonga, Calif., juicery employs HPP technology to help produce cold-pressed juices.

Posted: December 11, 2014

12/8/14 12:00 pm EST

FSMA & GFSI and Their Impact on Sanitary Machine and Plant Design

There have been updates to the Global Food Safety Initiative and the Food Safety Modernization Act that will impact OEM's and food and beverage processors. This webinar will review those changes and discuss what machine builders and processors need to do for future compliance.

Refrigerated and Frozen Foods Magazine

CoverImage

2014 December

Refrigerated & Frozen Foods' December 2014 issue features the 2014 Frozen Foods Processor of the Year—White Castle.

Table Of Contents Subscribe

COLD FOOD PROCESSING IN 2015

What are some key factors that play into the success of the cold food industry in 2015?
View Results Poll Archive

The Refrigerated and Frozen Food Store

ColdPackagingMaterialsGuide_products
Cold Packaging Materials Guide

A guide to cold packaging containers and materials.

More Products

Refrigerated & Frozen Foods Delivers

RFF Infographic 133x133Click here to see a snapshot of the many different ways Refrigerated & Frozen Foods delivers business and technology solutions to cold chain professionals.

STAY CONNECTED

facebook_2014 twitter_40px youtube_40pxlinkedin_40px

Buyer's Guide

Visit our Buyer's Guide!

Refrigerated & Frozen Foods offers a Cold Packaging Materials Guide, as well as a Cold Storage Warehouse Guide, the most comprehensive listing of cold storage warehouses.

Visit the Buyer's Guide page today!