Basics of energy efficiency for industrial, manufacturing facility design
Industrial and manufacturing facilities have specialty energy efficiency and sustainability needs engineers must include in new or retrofit projects
- Jaimie Ross Handscomb, PEng, Principal, Industrial Buildings, Stantec, Waterloo, Ontario
- Steve J. Sovak, PE, Principal, Salas O’Brien, Chicago
- Jeffrey R. Thomas, PE, CEM, CEA, GBE, CHC, Vice President, Lockwood Andrews & Newnam Inc. (LAN), Houston
Describe a recent project in which the building envelope was complex or unique.
Steve J. Sovak: We recently completed a project for HB Taylor, a food ingredient manufacturer. They have an existing production facility in Chicago and wanted a second local plant to increase production. They purchased an older existing warehouse building in Calumet City, Ill. As this was to be a food plant with high requirements for washdown, we designed the production rooms as rooms within the bigger room. The spaces were built out of 4 inches insulated cooler panel walls and ceilings. The ceilings were at an elevation that equipment serving the space below could be above and accessed from the cooler panel ceiling. This resulted in a very durable and cleanable surface for their production spaces, which was quicker to install and more cost effective than constructing masonry walls.
Describe energy storage systems at an industrial or manufacturing facility. What have you designed recently?
Steve J. Sovak: While we have designed a number of large photovoltaic systems, one of the limiting factors is the availability of a large cost-effective battery storage system. Currently if you are generating electricity from a PV array and you are producing more than you are consuming and you don’t have a storage system, you are forced to sell the power back to the utility company. I was at a recent seminar and learned that in southern California where PV systems are very prevalent, the rate at which the utility company will buy back your excess power goes to zero at times. Storage battery technology needs to improve to support the level of PV power generation now in place.
How has the demand for energy recovery technology influenced the design for these kinds of projects? Describe a mixed-use building in which the heat from the industrial or manufacturing section of the plant was used in other portions of the building.
Steve J. Sovak: Energy recovery has been used in industrial plants for years on a limited basis. Heat from a large air compressor captured to be used for plant heating or boiler stack economizers installed to preheat water or heat from large generator installation reclaimed to make hot water or steam. But, use of these systems is now becoming common place. Energy recovery on exhaust air streams is being used more frequently, but care needs to be taken if the exhaust stream is potentially contaminated. Run-around coils as opposed to energy recovery wheels should be considered.
What level of performance are you being asked to achieve, such as WELL Building Standards, U.S. Green Building Council LEED certification, net zero energy, Passive House or other guidelines?
Steve J. Sovak: Where we have had projects that were actually pursuing a certification program in the industrial or manufacturing arena, it has been with the U.S. Green Building Council LEED program. Many industrial owners do pursue the goals that the standards embody such as striving for net zero or minimizing waste or carbon footprint because those have a direct impact on their costs, but they do not pursue the actual certification process.
One project we are currently involved in is for the Greater Chicago Food Depository. They will be constructing a new approximately 60,000-square-foot meal preparation facility located on Chicago’s southwest side. They are pursuing a goal of LEED Gold certification. This is somewhat challenging as they are a nonprofit entity working on a limited budget. Also, their program is to produce both fresh and frozen meals for delivery, so it is a very energy-use intensive building.
What types of renewable or alternative energy systems have you recently specified to provide power? This may include photovoltaics, wind turbines, etc. Describe the challenges and solutions.
Jeffrey R. Thomas: LAN has designed and specified PV, compressed natural gas and combined heat and power plants for clients in recent years. In almost every case, the decision to implement an alternative energy system came down to simple economics driven by the commodity fuel markets. For example, PV in Texas has a 7 to 10 year payback due to relatively low electric rates. California has much better economics due to their higher tariffs. Smaller (2 to 3 megawatts) natural gas fired CHP has a similar payback due to the 10-year costs associated with the engine overhaul that comes due right about the time the system would have paid for itself. Larger plants, usually gas turbines, have a better payback if clients need both electricity and heat for their processes. LAN has one client that uses these turbines to generate electricity for about 7,500 tons of chilled water capacity and process steam for a health care campus. In short, a detailed investigation is required to match the alternative energy source to the demand to see if the economics work.
Steve J. Sovak: Most industrial facilities are very expansive low-rise buildings. They are well suited for the use of PV systems for producing electrical power. We had been involved in a number of warehouse distribution centers that have installed PV arrays to generate power.
What unusual systems or features are being requested to make such projects more energy efficient?
Steve J. Sovak: We have seen more recent interest in the use of geothermal systems at varying manufacturing facilities. However, this still has limited application due to the system temperature limits. We did work on a study using a gasification system to produce electricity. That is where items are burned at a low oxygen level while under pressure, resulting in very little emissions. The costs were prohibitive and the project did not go forward.