Prefabrication: A key to higher quality and profit

BY JOHN ABULARRAGE
contributing writer

Prefabrication is by no means a new concept. It has existed in the industry for more than 50 years and, although it is underutilized, it offers a number of important benefits. Prefabrication also presents some challenges, however, and it requires close attention to detail and a highly organized approach.

Advantages abound

It is generally accepted that prefabrication can save 50% or more in labor costs over site fabrication. It provides the ability to meet demanding schedule deadlines by allowing fabrication in advance of field availability. At times, we have had as many as a half dozen control panels prefabricated in our shop, waiting for the appropriate time for installation. This solves the problem created by the “wait and hurry up” jobs that would otherwise be impossible to complete in a timely manner.

Prefabrication provides a controlled and comfortable work environment with all the necessary tools at your disposal. It prevents the repetitive setup and breakdown on a daily basis usually required with field fabrication. On long distance jobs, prefabrication can reduce travel time and expense. It also permits unrestricted work hours, not subject to the time constrictions that may exist on a given jobsite. Ultimately, the quality of prefabricated work is much higher than the quality that can usually be achieved in the field.

A less evident benefit of prefabrication is training. Mentoring an apprentice under shop conditions with real-world applications is priceless. It acts as a bridge between the classroom and the field. I’ve found that the ability to train from theory through development to fabrication and, finally, to the installation of a control panel to be a most effective training methodology.

Planning is key

The prefabrication process is best accomplished with continuity of responsibility. If the same person is performing the site survey, fabrication and installation, any conflicts can be readily identified and remediated. Coordination and communications with related trades is also streamlined.

The process of prefabrication always begins with accurate measurement of the space available for the prefabricated equipment. You need to avoid what is referred to in the data processing industry as “garbage in, garbage out.” The last thing you want to happen is to deliver a prefabricated control panel that is larger than the available space to a jobsite.

Once the site survey is complete, it’s time to generate an accurate CAD drawing of the floor and wall space available for all of the system components, including control panels, boilers, tanks and supply and return piping that will connect to the control panel. This drawing must include any equipment from other trades that needs to be in the mechanical room. Access for servicing of the equipment is critical and needs to be documented in the drawing as well.

Starting from an accurate piping schematic, the basic layout of the fittings and components can begin. There are always many variations of the layout that can affect the overall dimension of the panel. Sequencing either vertically or horizontally can make a tremendous difference in dimensions in either direction. It always seems to amaze me that, regardless of how much space is available, it so often comes down to a matter of inches in order to make a control panel fit in the allotted space.

When laying out the components, consideration must be given to the hangers that will support the system. This sometimes requires adding additional length to piping between components to accommodate the hangers. Once the layout is decided, all dimensions must be confirmed with the mechanical room drawing. Then the actual assembly can begin.

The professional touch

At this stage, decisions can be made about the alignment of valves and components. While this alignment has little effect on the performance of the system, it adds to the overall cohesiveness of the finished project, without adding significant time to the fabrication. This visually important refinement communicates a high level of craftsmanship and professionalism. Don’t dismiss the value of this as merely “mechanical vanity.” Anyone who is impressed with the finished product will add that all important word-of-mouth element to your sales efforts.

While prefabrication is not for every situation, it can be an important key to higher quality and profit for every contractor. Almost every job offers the opportunity to prefabricate some aspect of it. If you have not tried prefabrication yet, start with a simple subsystem that you have typically fabricated in the field. Take your time. As you develop the shop techniques, the efficiency will follow, and the rewards will offset the investment in the learning curve many times over.

John Abularrage is the owner and president of Advanced Radiant Design Inc. of Stone Ridge, N.Y. His company has been designing and installing radiant heating systems for more than 25 years and has won numerous national awards. John is a certified instructor for the Radiant Panel Association.