Zoned Hydronics

By Leah Den Hartogh

Passion and artistry are probably two words that most technicians aren’t used to hearing when it comes to their work; however, in the hydronics industry, they are in many ways artists. Putting together a fully functioning mechanical room takes time and experience to get it right. Passion is the driving force behind why these technicians enjoy doing their work, day-after-day.  Each piece of the hydronic system has to come together to create this giant mechanical jigsaw puzzle.

“Sometimes you don’t even know what you’re building,” says Stephen Levy, hydronics manager—Prairie Region for Master Group. “I mean that’s the cool part; it’s like a blank puzzle. Cutting out the pieces and you’re almost putting it together yourself. It is a lot of fun.” That isn’t to say it’s an easy task.

“You can get into a lot of trouble quickly. But that being said, we try not to get ourselves into trouble as much as we can, but like anything, it’s all about the end result and working backwards to make sure that you have everything in place.” To ensure that the finished project is parallel with what the homeowner is looking to end up with, communication plays a key role.

As a rule of thumb, a contractor much listen and understand what the homeowner or end-user is looking for out of their system. Do they want their bathroom floor to be nice and toasty for when they step out of the shower? But also want their bedroom to be cool to sleep in? This all can be done via a zoned system, but the contractor first needs to know what the end goal is. In a sense, work backwards. Find out what the client’s wish list is and determine how best to reach each of those goals; make sure their expectations are realistic to the system installed, explains Mike Wills, national category manager—hydronics, water heaters, pumps for Wolseley Canada.

Body parts

The components within a hydronic system can vary depending on the application. Piping, manifolds, actuators, boilers, buffer tanks, control panels, valves, and pumps are all terms that are thrown around when it comes to different methods of designing a zoned hydronic system. “To determine the components used in a hydronic system, it’s usually customized to the system that we’re designing,” says Levy.

In Canada, the common practice is to use zone valves; however, that isn’t to say that pumps aren’t a popular method as well. The water needs to flow somehow. “The pump will push the water through the loops; the valves will open and close which will allow for fluid to pass through to that zone,” explains says John Wiehler, president of Wiehler Mechanical Ltd. You need a minimum of one pump and two-zone valves to justify a zone valve system.

By zoning a house or building, the benefit is that it’ll allow for temperatures to vary from floor to floor, room to room, it just all depends on how the building has zoned, says Vince Baggetta with Next Supply. “If I were to stress anything, it would be not to overcomplicate things,” says Baggetta. “I think hydronics has been complicated over the years because we can have so many zones. Just because you have the option of having multiple zones doesn’t mean you need them; it doesn’t mean you need to overcomplicate the system.”

That is to say that the industry doesn’t appear to be heading this way. In Europe, it is common to zone like crazy, or micro-zone. This could even mean zoning every single room in a home, reports Wills. This could be problematic for the entire heating system if precautions aren’t made. This might mean ensuring that the boiler, or heat source, can modulate and that a buffer tank is installed to take off some of that load; after all, you don’t want to overshoot or undershoot. It is also important to remember that over-zoning will require more maintenance because of moving parts and product failure. The homeowner should be aware that this might increase their costs over the years, says Wiehler.

Best practices

Controls are an essential component for zoning hydronic systems, they are essentially the brains of the operation. Thermostats are one way to communicate with a valve or pump. Within the thermostat market, there is an endless number of solutions available to satisfy the customer. This could mean a simple plug-and-play thermostat, or it could evolve into smart technology. “When we talk about zones, we are talking thermostats,” says Baggetta. “Whether you want Wi-fi or not, it’s based on the application and the user.” This also means that proper wiring choices have been made. “One thing we’re doing for all our jobs now is encouraging people to use shielded wiring because these Wi-Fi enabled thermostats are more and more common. It’s a good practice to start with good wiring,” says Baggetta.

Like with any trade, there are plenty of tricks that have been passed along from technician to technician. One such suggestion was to ensure that everything has been labelled properly, said Wiehler. “Label your heating pipes, label your wires, label your zone board every time because when you come back to troubleshoot, it can be extremely difficult. I’ve spent tens of thousands of dollars learning that lesson.” If the system isn’t properly labelled, the contractor ends up having to use thermal cameras to determine the problem.

One instance where labelling could have solved an issue before it even started involved a master bedroom and ensuite washroom. What ended up being the issue was that the two actuators that served each loop was reversed. When the master bedroom was looking for heat, it was going to the ensuite, explains Baggetta.

Ramping up

As previously mentioned, ensuring that the heating source, whether it is a boiler or not, can modulate can make the job a bit easier. “It should ramp up and down just like the pumps, based on how many zones that are calling. If you don’t need 100 per cent of the heat out of the boiler, it’s better to have 50 per cent—depending on what the turndown ratio is on the boiler,” suggests Wills.

At the end of the day, the designer and contractor are creating a system that will ensure the customer is happy and comfortable. However, that doesn’t mean that they are always aware that they are comfortable. They just know when they are uncomfortable.

When first testing the system, it is essential to do a full-run start-up with the thermostats all the way up. “That way a full call is on,” explains Wills. “Then as a contractor go get your coffee. Go to Tim Hortons, go down the street, I don’t care what you do, just walk away from the job for about an hour. This will allow you to make sure they fully open. That’s one of the biggest issues that we have with contractors going back to zone valves not working. Did you fully activate them? No; well okay. Do what I just told you and don’t plug the system for an hour.” Even if a contractor forgets to do this little trick, they can still come back and easily train the valves to fully open.

At the end of the day, don’t forget the basics. If there are issues, there are plenty of resources available including your local wholesaler. “As I learned very early on in my career, the devil is in the details,” says Levy.

“The subject is vast, and it takes years for people to understand and balance it all out,” says Bob Williams, Tropical Heating & Air Conditioning Ltd. “But good design and good practices will keep you out of trouble.”

After all, hydronics people love what they do and since it’s still a small percentage of the market, it helps lend itself to the artistry behind getting the chance to practice their craft, says Wiehler.