Prefabrication Raises the Bar

Written on: December 12, 2022 by Tom Soukup

I’ve been in the home comfort trade for 20 years. Much has changed in that time, but two things in particular are very different from when I first lit a standing pilot.

First, equipment has gone from “dumb” to “intelligent.” That includes boilers, controls, T-stats, tools and even utility vans. Second, society wants instant gratification. They want it now, and they want it perfect. Both of these changes impact our profession, and neither is going to change. So we need to.

That means more preparation, thoughtful design and precise execution. The days of “winging it” are long gone for our industry. Now, everything must be planned, calculated, analyzed and accounted for.

I realized this a while ago and started making changes in the way my company operates. The big turning point, though—the “lightbulb” moment, as some would say—came when I first pre-fabricated a boiler system.

These days, 90% of the boiler systems we install are pre-assembled in the shop after carefully measuring the mechanical space and taking many photos of the area in which the system needs to fit. We’ve found that this creates a better final product, reduces our time on-site, cuts overall labor by 20% and drastically curtails system downtime during the retrofit.

Room (and time) to work
Our prefab shop has plenty of space and plenty of light. Working on a table or stand means we’re not stooping over or resting on our knees. Big equipment/tools are already in place, so we’re not wasting time with setup and tear-down. We have jigs and spacers for a variety of system types and sizes, depending largely on the number of boilers in a system (more on that later).

The shop offers a relaxed atmosphere; no customers watching, no other trades fighting over power outlets, no messes, no weather considerations, no loud noises, etc. This all means greater attention to detail. Burn permits and fire watch are also a thing of the past. Hydronic racks are accessible from all sides, unlike working against a mechanical room wall.

We make our racks out of unistrut and build the system up from there. If the system is meant to heat a pool, or will be exposed to other caustic environments, we use stainless steel rack material.

We preassemble the entire boiler system to include wiring and all components. Everything is assembled loose and will be press connected later in the field. Once the system is complete, we take pictures, label everything with tape, put it in a box and reassemble it on-site like a simple jigsaw puzzle.

Cost, redundancy, turndown
Prefabbing boiler systems makes my company more competitive and provides a better product. Plain and simple, it just makes the job easier. Through the process of developing our pre-fab methods, we found another trick to add value to our commercial and multi-family installations.

Prefabricating boiler systems makes it easy to install multiple condensing boilers. We’ve found that it’s less expensive, per British Thermal Unit (BTU), to install multiple, small boilers than a single big one.

For example, many of the systems we replace require somewhere in the neighborhood of 450 to 550 thousand BTU per hour (MBH). In those situations, we fabricate hydronic systems with three U.S. Boiler Company K2 condensing boilers. If we need less firepower, we can drop to a smaller model. Need more heat? Add more boilers!

As I mentioned, equipment cost per BTU is usually slightly lower with multiple boilers, but there are many other advantages, such as redundancy with multiple boilers. The units are physically easier to handle. Turndown ratio goes way up. In the case of the K2 boilers, three boilers provide a full 30:1 turndown. Pair that with 95% annual fuel utilization efficiency (AFUE), and we’re talking about some major energy efficiency.

All that turndown also means that we can be more flexible in our boiler sizing. By properly staging the units through the K2’s Sage controls, the boilers will be running long hours at minimal input. That’s the perfect recipe to low fuel use and long boiler life cycle.

Multiple boiler installations are preferred for these many reasons, but can become a major headache and piping mess in the mechanical room without a solid design and the ability to prefab system components.

Customer satisfaction
For just a moment, forget about cost and efficiency. Just focus on the customer experience provided by a company that prefabs their boiler systems. It’s here you’ll find the biggest selling point for most commercial facilities, where time is critical and managers are extremely busy.

For example, we were recently hired to replace the boiler system at a retirement facility. We erected the entire system in our shop weeks before demolition day. On day one of the actual install, we had the old system torn apart, all of our racking installed and piping started. Day two had the boilers in place and fired. Day three included the finishing touches, control details and customer orientation. That can only be done through prefabrication.

Beyond speed, prefabbing boiler systems has other advantages. Building the system before the project starts eliminates change orders. Also, we take full accountability of the system, eliminating the footwork and orchestration needed on the customer’s part. They don’t need to be concerned about an electrician, a plumber and a gas tech, in addition to us. We provide one point of connection for each of these trades. ICM


Tom Soukup is the Principal of Patriot Water Heater Co. with more than 20 years as a hydronic designer and installer. He specializes in high-efficiency and Green technology and brings his expertise to custom commercial work, pool heating and agricultural projects. Email him at: