Best Practice Guide

Food and Beverage Growers and Processors

Introduction

Planning an Energy Program

Funding and Approval

Commissioning

On-the-Farm Energy Use

Lighting

Building Envelope

Central HVAC System

Boilers

Steam

Combined Heat and Power

Compressed Air

Energy Use Basics

Proper Maintenance

Proper Operations

Waste Heat Recovery

Refrigeration

Motors

Demand Response

Distributed Generation

Water Use


Fetzer Vineyard

J Vineyards and Winery

Mission Foods

S. Martinelli and Company

Sara Lee

Vineyard 29


View the Glossary

Compressed Air

Waste Heat Recovery

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Waste Heat Recovery and Heat Exchangers
Even in a well-maintained compressed air system, as much as 80 to 90 percent of energy is converted to heat. A heat exchanger could capture anywhere between 50 to 90 percent of the thermal energy otherwise lost and reuse this to heat air or water.

It is easiest to adapt packaged, rotary screw compressors since a heat exchanger is not needed. Add ducting and a fan that prevents backpressure on the compressor cooling fan. Warm air can then be vented to desired areas. The closer the compressor is to the area of use, the more efficient this system will be.

Water can be heated by adding a heat exchanger to either a rotary screw or a reciprocating compressor. The heat exchanger collects thermal energy from the lubricant coolers, using this to heat the water.

The U.S. Department of Energy estimates that air compressor heat recovery can reduce a facility's total energy use by about two percent with an average simple payback of 10 months.


Resources

Improving Compressed Air System Performance: A Sourcebook for Industry. Compressed Air Challenge and U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy. The Compressed Air Challenge(CAC) is a voluntary coalition of industry, manufacturers, state research and development agencies, energy efficiency organizations, contractors, and utilities. CAC provides a number of resources online, including best practices, tips, and case studies, as well as live trainings held throughout the country. The mission of CAC is to develop and provide resources that educate industry on the opportunities to increase net profits through compressed air system optimization.

Efficiency Improvements in Industrial Compressed Air Systems. Pacific Gas & Electric Company, April 25, 1997.

Air Compressor Energy-Saving Tips. Minnesota Technical Assistance Program, University of Minnesota, 2003.

U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Industrial Technologies Program, Compressed Air Best Practices.

Wise Rules for Industrial Energy Efficiency: A Toolkit for Estimating Energy Savings and Greenhouse Gas Emissions Reductions. U.S. Environmental Protection Agency, ENERGY STAR, September 2003.

The Compressor Guy website, archived files on Profit and Productivity Thieves and Unregulated Use.