Take The High Road
John Siegenthaler, P.E.
This will be a great year for hydronic heating professionals. It may not be a great year for those who see hydronics as the daily grind of soldering copper, strapping down PEX and hoping it all works with the main switch is flipped on.
Newcomers to hydronic heating need to operate with a professional attitude from Day One. As in any career, they’ll encounter plenty of forks in the road as they hone their technical and business skills. Choosing correctly can make the difference between a satisfying pro-fessional career and an endless series of complaints, callbacks and even litigation from dissatisfied consumers.
Here are a few tips for rookies from someone who has seen the “thrill of victory” as well as the “agony of defeat” when it comes to heating buildings with water.
Use The Plates: Anyone entering the field of hydronics is likely to pursue radiant floor heating projects. They’ll encounter a plethora of choices from manufacturers as well as a range of advice from wholesalers. There’s little doubt one of the options they’ll hear about is stapling tubing to the underside of floors or the sides of floor framing without any enhancement from aluminum heat transfer plates such as the installation in Figure 1.
A question to those rookies contemplating their first plateless staple-up installation: How lucky do you feel? Perhaps, if you’re fortunate enough to be installing the system in a very well-insulated house, located in a relatively mild climate, with low-resistance floor cover-ings, and owners who are comfortable in lower air temperatures, a plateless staple-up sys-tem will produce results that are above the callback threshold. Remove any of these as-sumptions and you’ll be skating on very thin ice.
Rather than getting “chilled” by a radiant system with a case of thermal constipation, I sug-gest working with proven installation methods (slab-on-grade, thin-slab, tube-and-plate, or panelized systems). Do these until your feet are firmly planted on warm floors. Once you’ve seen how these systems perform, you’ll be in a much better position to judge for yourself how some of the “fringe” installation methods will perform.
Get Second Opinions: When you’re told something that suggests current meth-ods of hydronics installation are obsolete or much more complicated and expensive than necessary, it’s worth doing some research before you buy into the proposed miracle meth-ods or materials.
Your customers expect the choices you make on their behalf will provide decades of reli-able operation. They will seldom challenge your decisions, even in situations where thou-sands of dollars worth of materials and labor are at stake.
Ask for third-party test results on new products. Get them (if available) and read them. Ask your source of information for contacts that let you follow up to verify performance claims. Manufacturers of legitimate products will be more than happy to support your inquiries.
Otherwise, check your general liability insurance coverage and be prepared to go it alone should anything not go as expected.
Wise Up: One of the best ways to sift through the hundreds of choices for materials and methods is to attend an industry conference, such as the Radiant Panel Association’s Radiant Expo, Aug. 24-26 in Hartford, Conn., or either of two Canadian Hydronic Conferences - Foothills Conference, April 19-20 in Edmonton, or the Great Lakes Conference, May 15-16 in Toronto.
Besides attending generic seminars, you can listen in as your peers debate sometimes-controversial issues. You’ll have plenty of opportunity for second opinions from people who’ve already passed over hurdles you have yet to encounter. Continuing education is an inseparable requirement of being a professional in any field. Set aside the time and budget to maintain your professional status.
Don’t Overpump: Our industry has plenty of 95+ percent efficient boilers. Like-wise, the forced-air industry has at least as many 95+ percent efficient furnaces.
We can’t offer combustion efficiencies better than furnaces, but we do have the potential of beating the forced-air industry in the area of distribution efficiency (e.g., how much electrical power is needed to deliver heat from where it’s generated to where it’s needed).
The key word here is “potential.” Indiscriminant use of wet-rotor circulators quickly adds wattage to otherwise thermally efficient systems. I’ve personally visited homes with 40 cir-culators, and have been told of residences containing 100 circulators!
Such systems have distribution wattage requirements approaching forced-air systems of similar thermal capacity. They needlessly plunder the huge thermodynamic advantage of moving heat using water rather than air.
It’s far better, at least for the time being, to use a small number of higher efficiency and ap-propriately sized circulators along with valves for micro-zoning instead of dozens of wet-rotor circulators.
An even better option that will soon be at your disposal is the use of “smart circulators” that continually adjust their wattage based on the needs of the distribution system. Here is a product that truly represents a quantum leap in hydronics technology. Get on board as soon as these products are available to you.
After you’ve learned to be a good steward of circulator wattage, be sure your customers know about the distribution efficiency advantage your systems offer over competing op-tions.
Care For Your Fluids: One area of hydronics technology that’s had scant atten-tion is maintenance of system fluids in residential and light commercial systems. Most of these systems are simply filled with the water available on site. Few are internally “washed” as part of start up.
This leaves soldering flux, cutting oil, and maybe even some dirt inside the system to blend with the water’s own chemistry. In some cases, the results will gum up air vents, clog circula-tors and corrode the system to the point where it has to be ripped out and replaced. Glycol-based antifreezes add even more potential for problems if not properly stabilized and main-tained.
Those new to hydronics as well as seasoned hydronic pros should take a hard look at what they’re doing to ensure the fluids in their systems do not create problems over the long haul. We all take care to service the fluids in our trucks, why not treat our multithousand dollar hydronic systems with the same diligence?
Look Beyond First Cost: Assume you were selecting a circulator to provide a flow of 16 gallons per minute against 9.4 feet of head. One option is a $250 circulator with a peak wire-to-water efficiency of 40 percent. Another option is a $125 circulator having a 22 percent peak wire-to-water efficiency. Which would you choose?
Assuming both circulators operated for 3,000 hours per year for more than 20 years, and that electricity costs $0.10/kwhr, the circulator with 22 percent peak wire-to-water efficiency would cost $341 more to operate than the circulator with 40 percent efficiency. And this doesn’t even factor in any increase in electrical cost!
Total lifecycle owning and operating cost gives a truer picture of the “net cost” to the cus-tomer than does installation cost alone. Few consumers tend to think in such terms. For ex-ample, when was the last time a customer questioned your choice of circulator for a given situation? Still, it’s the job of hydronic professionals to guide customers to choices that benefit them.
Be prepared to defend sound choices based on life-cycle costs against the “I can get the same thing from someone else for less money” argument.
Parallel Beats Series: There are plenty of choices for hydronic distribution sys-tems. They have names like series loop, primary/secondary, two-pipe and homerun. Fun-damentally, they all come down to the concept of series vs. parallel flow.
With series systems, the loads are all connected in sequence and temperature drops from one active load to the next are always present. Head losses also add up as more components are connected into a loop. Some designers properly account for such condi-tions and some don’t.
With series flow, the system often suffers from inadequate flow and excessively high temperature drops. The end result is that heat does not get delivered when and where it’s needed.
In my opinion, it’s much better to avoid the potential pitfalls of series circuits by using dis-tribution systems with parallel flow paths, such as two-pipe or homerun systems. They provide the same water temperature to each load and typically allow flow balancing to adjust heat output. They also allow servicing of one distribution subcircuit without shut-ting down the entire system.
Get Your Systems Online: The coming years will see more HVAC systems ca-pable of being accessed through the Internet. More and more control products are be-coming available to allow Internet-based data logging, troubleshooting and setting ad-justments from remote locations.
I’m convinced that Internet accessibility represents the largest paradigm shift in control technology for residential and light commercial HVAC systems in years. Savvy hydronic pros will not want to miss out on the opportunities in hydronic-specific controls as well as the much larger building automation market that these control systems make possible.
My suggestion is to research currently available Internet-accessible control systems, choose one you feel comfortable with, and commit the time and resources necessary to learn how to make it sing sweetly. The time you invest will elevate the services you offer above those of the average Joe Wrenchturner.
Almost anyone can lay down a circuit of PEX tubing. Far fewer can configure a net-worked control system that allows their clients to keep track of or adjust what’s happen-ing in their building from almost anywhere in the world.
Craftsmanship Still Counts: No matter how technically sophisticated our hardware options become or how much we learn, nothing replaces a continuing com-mitment to craftsmanship in every system we design or install.
Never view the service you offer as a commodity. Instead, think of every new project as a “custom” system designed to address specific technical requirements, customer pref-erences, and budgetary constraints. Resist the temptation to lower standards to save time or cut cost, even when it costs you a few jobs to competitors.
Just because other “installers” in your area do it doesn’t necessarily mean it works. In the end, taking the high road always leads to success and a fulfilling career giving people the comfort they seek. Think and act like a pro because you are one.
Wishing you a prosperous 2007.