As a writer you know you’re a "seasoned citizen" when some of those you work with are preparing to welcome their first child while you’re waiting for the arrival of grandchild #13. Another sign is when you rely on those grandchildren to solve quirky issues involving a smart phone or a website.

While I admit to not being fully informed on the latest things from Google, Apple, Chat GPT, or social media, I’m confident that I can still pass along advice to those who are new to the hydronic industry, especially those involved with designing systems.

Many of the suggestions that follow are based on my own mistakes in earlier years. Thankfully none of them were catastrophic. Most involved interaction with clients and how engineering services were delivered.

Here they are - in no particular order:

1. When discussing hydronic heating with a potential client describe benefits rather than technical features.

Early in my career I was fascinated by technology such as cross-linked polyethylene tubing, variable speed injection mixing, and outdoor reset control. I wanted to share my enthusiasm for technical details with potential clients who were interested in hydronic heating. Without realizing it, the more detail I went into, the more I inferred that hydronic heating was exotic, expensive, and only capable of being installed or serviced by a limited number of "artisans." I eventually learned that the vast majority of clients were not interested in technical details, they just want to be really comfortable. Comfort is the preeminent benefit of hydronic heating, and in the eyes of most clients it’s far more important than the technical details used to achieve it.

2. Don’t reduce prices when asked for a "deal:

"Make an offer" might be appropriate on eBay, but it’s not appropriate for professional services.

I’ve developed pricing for hundreds of engineering projects, and have occasionally been asked "can you do this for less." My response has been a polite but firm - no.

Responding in any other manner implies that the quotation was "padded," or that I really couldn’t afford to loose the work. Either implication suggests poor judgement, or questionable competency. Neither should be associated with professional services.

Furthermore, a potential client who’s trying to chip away at pricing is a "tip-off" that other disagreements or deviations from the scope may lie ahead. It’s alway better to politely and confidently state that your pricing, scope, and terms are as written in the agreement presented to them. If the client cannot accept that pricing, scope, or terms, thank them for their time, sincerely wish them success with their project, and politely decline the work.

3. Don’t loosely specify systems:

Over the years I’ve been dumbfounded at how some engineering specifications leave so many "loose ends" when it comes to actually specifying hardware. There are pages of boiler plate language that reference ASTM standards, etc. but then nothing more than a generic open-ended description of critical items such as what make and model boiler will be used, or how the system will be controlled.

Personally I view such loose ends as a failure to ensure that all hardware has been selected to operate as a system. It might also be a veiled attempt to shift some of the leg work necessary to complete the design to others (e.g., venders, or contractors).

Sure, I understand that hardware submittals by the contractor will be forthcoming in such situations, and that approved substitutes are possible, but why create a situation where so much follow up work, both on the part of the contractor and engineer is necessary? Personally I think that writing "tight" specifications minimizes potential incompatibility issues, reduces liability, and demonstrates thorough engineering practice.

4. Never let clients select hardware:

If I told a client who hired me to design a hydronic heating system that a 1" thermostatic mixing valve costs $125, and that a 1" motorized mixing valve with controller costs $800, and that their intended function was similar, then gave them their choice, which valve would most of them select?

The majority would select the less expensive valve - especially since I sort of implied that the two valves provide a similar function. The client has no idea what the Cv of a valve is, no idea of how the motorized valve and controller can protect the boiler against flue gas condensation, and no idea about the temperature accuracy and reliability attainable from either valve.

I use the following analogy when a client implies they wants to select hardware for their system: When you purchased your last new car, did you have a choice on what type of spark plugs it came with? Of course not. That selection was made for you - hopefully by engineers who understood exactly what spark plug characteristics were required for the car’s best performance. You trusted those pros to make the right selection. The same applies to hardware selected for hydronic systems.

5. Always have a written agreement for the services you will provide:

Many years ago I made the mistake of having what I understood to be a verbal agreement for design services. I provided the initial portion of those services, invoiced for that work, and was immediately challenged by the client. They had no intention of paying for work that, in their opinion, only involved site visits, meeting with an architect, and discussing possible approach to heating their building. From their standpoint I should have provided all that "pro bono."

In those early years I really needed the income so I challenged the already disgruntled client in small claims court. I lost. The judge, who I could tell was empathetic to my situation, simply stated that without a written and signed agreement I had no basis for charging anything.

From that day on every project started with a written and signed agreement for scope, time frame, payment terms, and other details. The vast majority of clients I’ve since worked for fully understood, respected, and even appreciated the need for such an agreement. The two who, after discussing the agreement, still stated that they could not abide by it, provided a heads up that it was best to decline the work.

6. Keep systems as simple as possible:

Hydronic system don’t have to be complicated to be sophisticated. Quite the opposite. The simpler the system can be and still provide the required functionality, the better the design.

One example would be reducing a design that uses 3 or 4 mixing assemblies to achieve slightly different supply water temperatures to different zones, to a system that only requires one mixing assembly. This is done by varying tube spacing in floor heating system, or changing the size of panel radiators. If the required zone supply temperatures at design load are all within +/- 5 ºF of the average supply temperature it’s very likely a single supply temperature is workable.

Another example is using a reverse indirect water heater as both a domestic water heating device, a hydraulic separation device, and a buffering mass for a highly zoned distribution system. One tank potentially replaces two tanks and either a pair of closely spaced tees or a hydraulic separator.

Always look for synergy in design, coaxing as much functionally as possible from individual components.

Avoid the temptation to go "hog wild" with hardware, especially controls. Good design is not about building a "trophy system" containing the most hardware possible - even when the client can afford it. Instead it’s about building a system that delivers superior comfort, using the simplest and most cost effective approach, while remaining reliable, serviceable, and efficient for years to come.

7. Don’t sell "a couple of hours" of your time:

I’ve been asked several times if I would "sell" a couple of hours of time to review a project and make recommendations. While I respect that the person making the inquiry wanted to pay for professional advice, I also know that any involvement in a project, even pro bono recommendations, could be an exposure to potential liability. The old saying " In for a penny, in for a pound" applies.

Like many engineers, I want to help in situations where problems are at hand, or soon will be, and where an alternative approach would provide better results. Still, I limit any conversations in such situations to suggestions, I don’t charge for those suggestions, and I often pass along contact information for other professionals who could help complete the design or installation.

8. Always document your designs:

In my opinion one of the most significant and recurring problems with hydronic system design is the lack of good documentation. As a designer you do not want to be the only person alive who understands how a specific system is supposed to operate. Instead, you want to leave a trail so that any reasonably competent technician can quickly understand how the system is supposed to operate.

Complete documentation for a system should include:

1. A detailed piping schematic, including all pipe sizes, minimum straight lengths, or other critical dimensions such as for turbulence reduction or thermal traps, specific make / model listings for all equipment with the exception of common fittings.
2. For radiant panel projects documentation should include a tubing layout on a scale drawing of the floor plans. All circuits should be labelled. All circuit lengths should be listed. All control joint locations should be identified. Clearances from objects such as structural columns, toilet flanges, etc. should also be noted.
3. A detailed wiring schematic. Point-to-point wiring including all wire types, and sizes, breaker ratings, grounding requirements, shielding requirements, and separation of low and line voltage wiring.
4. A detailed sequence(s) of operation in all possible modes.
5. Initial settings for all controllers in the system.
6. Water quality requirements.
7. Description of startup and commissioning procedures.

All documentation should be carefully cross-referenced. For example, when a circulator is labelled as (P2) in the piping schematic be sure it’s also labelled (P2) in the electrical schematic, and all other documentation. When the project will be bid a detailed set of specifications should be provided. Don’t leave any "loose ends" in those specifications.

As an engineer your job is to impartially evaluate the "reality" of these options in the context of a specific building, budget, and expected outcome, select an approach that’s in the best interest of your client, and to the level expected, explain your findings. In doing the latter it’s important to base discussions on physical facts and principles rather than unsupported opinions or marketing claims.

9. Design for the present - and the future:

Be sure your clients understand that a hydronic system is a long term value proposition. A well-designed, properly-installed, and reasonably maintained hydronic distribution system can last for decades. In all likelihood it will outlast its first heat source, maybe even its second heat source. The marginally higher costs associated with designing for low water temperature heating at present, (which in my opinion is nothing higher than 120 ºF supply temperature at design load), helps ensure that the original distribution system and heat emitters will remain compatible with future heat sources - such as a heat pump replacing a boiler.

Talk to your clients about possible future expansions of their building, and how your current design might be able to streamline the heating or cooling needs of that expansion. These discussions demonstrate that you’re taking a strong personal interest in the project rather than just turning the crank to generate another "adequate" system for the here and now.

10. Be prepared to support your recommendations:

There are obviously many choices when it comes to a person selecting a heating or cooling system for their building. There’s also incessant marketing to steer opinions toward specific approaches and specific products.

As an engineer your job is to impartially evaluate the "reality" of these options in the context of a specific building, budget, and expected outcome, select an approach that’s in the best interest of your client, and to the level expected, explain your findings. In doing the latter it’s important to base discussions on physical facts and principles rather than unsupported opinions or marketing claims. Anticipate what questions or concerns your client might have, and demonstrate that you’ve done your due diligence to address them. Make sure your client’s expectations are rational, reasonable, and most of all deliverable.

Lessons learned

Perhaps you’re thinking that I should have anticipated some of the less-than-ideal experiences described above before they occurred. In retrospect, my eagerness to seize an opportunity for designing a unique system for each client likely did cause me to proceed, at times, more "informally" that I should have. Still, I count all these experiences as blessings, and I offer all of the above advice with humility, hoping that some of it might help those who follow.