tekmar

By Jason Richards, Hajoca Corp.

I’ve seen a lot of creative ways to provide emergency heat to buildings during no-heat situations, but maybe none as original as a project we became involved with early this year at an upscale rural property near Reading, Pa.

The 12,500-square-foot building, one of many on the 100-acre property, houses a heated pool, spa, full size tennis court, kitchen and locker rooms.  When the old sectional boiler used to heat the facility failed mid-winter, maintenance staff turned the pool water temperature way up.  This not only held the natatorium at a safe temperature, but waste heat from the pool heating equipment kept the adjacent tennis court from freezing.

With 37 employees, Summers & Zims serves southeastern Pennsylvania from their headquarters in Atglen, Pa.

Mechanical contractor Summers & Zims, Atglen, Pa, was called in January to handle the no-heat call. The 37-person company had served the property owner in 2013 when they installed an extensive snowmelt system.

Joe Henderson, plumbing project manager, responded to the call and found that the large boiler was beyond repair; a replacement was needed immediately.

“Jason Richards, at Hajoca, and I began designing a replacement,” said Henderson. “There was a 500-gallon fuel oil tank on the property for the hydronic system and backup generator, and there was also an LP tank for the pool heater. The problem with replacing the original oil boiler with a propane unit was that the existing LP tank wasn’t large enough to handle the additional load. Plus, a second LP tank wasn’t immediately available.”

We didn’t know it then, but that was the first instance we experienced where major product availability issues would impact our decisions during the design process. Luckily, the supply chain challenges ultimately resulted in an even better system than we planned for initially.

Collaborative design

We continued the design with a multi-boiler approach. The original plan was to install a single large sectional boiler, but supply chain issues caused some trouble. I consulted with Dave Raabe, at ROI Marketing, and we learned that the boiler we wanted wouldn’t be available for a few weeks.

“This project took place at the height of the product availability challenge,” said Raabe. “The larger boilers weren’t available, so we looked at using three smaller MPO-IQ boilers, made by U.S. Boiler Company. These were immediately available. Ultimately, installing three boilers provides three stages of heat input for higher efficiency, and it also provides a level of redundancy. The smaller boilers also meant that the units could be wheeled into the mechanical on hand carts, instead of being field-assembled.

As a result, the design team selected three, 189 MBH boilers.

“We’ve come to love the MPO-IQ,” said Henderson. “We’ve installed tons of them. At 87 percent, they’re the most efficient, dependable oil boiler we’ve ever used.”

This design yielded a three-stage oil-fired system, which is uncommon in a residential/light commercial application. It provides some redundancy and, more importantly, allows the system to fire at lower input based on outdoor reset.

Controlling the boilers became the next question. Summers & Zims’ HVAC trainer and in-house tech support, Kenny Walker, has a great deal of experience with tekmar controls and had used the tekmar Boiler Control 274 for staging multiple boilers on numerous occasions. The property owner also wanted to remotely monitor the system through WiFi, so the new tekmar Smart Boiler Control 294 was selected.

Using the Watts OnSite web or mobile applications associated with the tekmar Smart Boiler Control 294, Kenny Walker can monitor the boiler system from his desktop or mobile device.

Rapid installation

Summers & Zims, originally Summers Brothers Plumbing & Heating, has been in the business since 1930. They merged with Zim’s Sales & Service in the 70s, forming the company it is today.

I’ve known a lot of their people for a long time, and can speak to their professionalism. They’re what I’d call “do the right thing” kind of people.  Joe Henderson and I go back 25 years, even before I joined Hajoca.  He’s a very sharp hydronics guy. When it came time to install the system in a hurry, I knew they could handle it.

For the install, Walker was joined by Todd Lease, head plumbing technician, Andrew DiEugenio, journeyman plumber, and Austin McGhee, apprentice.

The boilers were rolled into the mechanical room and a primary-secondary piping configuration was used to connect them to the system loop. The fuel supply line to each boiler features a Tigerloop fuel oil deaerator.

“We install a Tigerloop on every oil-fired system we install,” said Walker. “They cut down on nonsense service and emergency calls by cleaning up ignition and burn, which creates less soot in the heat exchanger. We also like that they allow us to use spin-on oil filters, which catch small dirt particles and reduce nozzle failures.

Kenny Walker, Summers & Zims HVAC trainer and in-house tech support, installs a Tigerloop Ultra oil line de-aerator.

“If the homeowner isn’t attentive to the amount of fuel they have left in the tank, running empty isn’t such a big deal,” he added. “The Tigerloop provides a two-pipe system from the oil pump to the unit. This way, the oil pump will self-prime, meaning the owner or the fuel delivery tech can simply hit the reset button on the primary control once oil has been delivered.”

Flexible fuel lines were used from the Tigerloop to the boiler’s Beckett burner.  To provide easy access to the three-pass heat exchanger, the MPO-IQ features a hinged front door, where the burner is located. By using flexible lines instead of hard pipe, service techs can open the boiler without removing the fuel fitting at the burner.

“Providing deaeration is even more critical on a multi-boiler installation like this because the more times you Tee off of the fuel line, the more opportunity there is for air to enter the fuel supply,” continued Walker.

Venting the boilers was done as deliberately as supplying the fuel. The existing chimney was large enough, but common venting the three units had to be done carefully.

“We couldn’t just run three, six-inch vents into a common stack, because the distance between the boilers and the main stack were slightly different,” explained Henderson. “The first two boilers join into an eight-inch vent, which increases to 10 inches as it picks up the third boiler and exits to the chimney.”

Control

When the original boiler failed, the homeowner decided that he wanted to monitor the heating system regardless of where he was, and he also made the decision to sign a service agreement with Summers & Zims.  For both of those reasons, Henderson wanted to find a control solution to stage the boilers and provide web-based monitoring. That said, they also wanted to avoid the use of a complex, costly building automation system.

“Jason had recently told us about the new tekmar 294,” said Walker. “So when we bought the boilers from Hajoca, we also bought the control. The 294 is similar to the 274, but with more features, a touch screen, and most importantly, remote monitoring capability. It can also send me texts, emails and push notifications for a wide variety of alerts.”

Kenny Walker installs the tekmar Smart Boiler Control 294.

The control stages and rotates the boilers, as well as handling outdoor reset, DHW priority, warm weather shutdown, etc.

In a typical MPO-IQ boiler installation, the onboard boiler control features optional plug-and-play cards to provide outdoor reset, low-water cutoff and aquastat. In this system, the tekmar 294 replaces all but the low-water cutoff card.

“The 294 was easy to install, and I can pull up and make setpoint changes to the customer’s system at my office or on my phone,” said Walker. “Right off the top of my head, we have half a dozen other systems in the field that would benefit from the use of this control. Each one can control four appliances, and they’re expandable to 16.”

Within a week of the old boiler failing, the new hydronic system was heating the building, and the pool heater was turned back down to its normal operating temperature.

I think this job—and the speed at which it came together despite supply chain issues—is a testament to Summers & Zims. The whole company shows up and honestly tries to do the very best they can.

I know it’s the start of summer and you’re thinking, “who is thinking snow and cold temps?” But it could be the best time to ramp up your snowmelt game for the upcoming winter season. Once upon a time, commercial snowmelt systems lived independently, with little concern about the larger mechanical environment they were often a part of. Typically, a boiler provided heat and a smart tubing layout, properly circulated, offered thermal distribution.

Voila! As if by magic, tropical warmth gently melted away midwinter precipitation from parking lots, walkways, ramps and driveways.

All good things change, and occasionally for the better. As for modern snowmelt systems, their renaissance has come in the way of—you probably guessed it— improved and more sophisticated controls. Now, snowmelt systems can integrate with BAS (building automation systems).

It only makes sense that snowmelt systems would eventually cross that bridge. Getting there, however, wasn’t without challenge.

BAS networks, by design, are largely “inclusive.” That is, their purpose in life is to integrate, control and monitor as many of a building’s key functions as possible, including heating, cooling, ventilation, lighting and other important operations.

Yet, because snowmelt systems operate outside a building, and are exposed to ambient conditions outside the envelope—with conditions that change quickly, often requiring far more than simple on/off function—BAS systems are challenged by their limitations. The key frustration expressed by design engineers, installers and building owners alike is that the ever-changing nature of outside, ambient conditions defies the constraints of most automated controls.

For this reason, anyone attempting to tie commercial snowmelt function with a BAS confronted a giant hurdle.

Fortunately, those impediments may now be things of the past.

The nature of the beast

For the longest time, achieving proper connection to and communication between snowmelt controls and a BAS was the seemingly impossible task. The two key parts of that puzzle were a.) sensors didn’t want to communicate digitally with the BAS, and b.) controls were mostly incapable of anything more than on-off operation. Maintaining idle operation, controlling gradual increases in temperature, or especially measured deactivation—these became the key challenges.

After all, if snowmelt system deactivation happens too soon, winter accumulations may pile up, or snow may melt prematurely, turning into treacherous ice. Or, if a system demands too much heat, or stays on too long, it punishes the building owner with unexpected operational costs.

For many years, there were many reverse-engineered attempts to connect snow and ice sensors with building automation systems. However, more recently, new technology has been developed to meet this challenge.

This new technology helps connect these two previously disconnected functions by receiving input data and sending information from sophisticated sensors directly to the building automation system, which ultimately tells the snow melting system to turn on or off.

A snow and ice sensor interface communicates directly with a BAS controller through BACnet MS/TP protocol, letting the BAS know to engage the on and off function of a snowmelt system when the outside sensors detect snow or ice. This unique piece of technology has quickly turned a traditionally inefficient process into a smart and truly automated system.

Having the ability to interface snow and ice sensors directly with any BACnet controller is not only creating more efficient snow melting systems for facility and building owners, it’s making it easier for contractors to have a simple, standard solution that can be easily applied to any snowmelt job—without custom coding or complex installation.

Despite its simplicity, connecting a snow and ice sensor interface to a BAS should incorporate many functions, also known as objects (see bullets below). The device itself is designed to be installed in a mechanical room, or at any remote location on site—perhaps in a service room closer to the snow melting area.

The list of data objects shared with the BAS controller should ideally include:

• Snow or ice has been detected
• Snow or ice has not been detected
• Outdoor air temperature
• Slab temperature
• Slab target temperature
• Snow/ice sensor sensitivity
• Warm weather shut down (WWSD)
• Cold weather cut off (CWCO)
• Error codes

As is often the case—and especially when new technology is introduced—questions arise. Here are some common questions from professionals in the field:

What happens if ambient conditions are too cold, or too warm?

Interface features such as warm weather shut down (WWSD) and cold weather cut off (CWCO) are particularly useful in ensuring the snow melting system is only running when needed. For instance, with CWCO, when outdoor air temperature is too cold (below CWCO setting), the BAS heat source is not able to increase the slab temperature to melt snow or ice. Features like this create critical efficiencies and save loads of energy.

With the right technology in place, the interface sends a signal to the BAS to turn off the snow melting system. Once the outdoor air temperature increases above the CWCO temperature setpoint, the interface will communicate to the BAS to turn on the snow melting system and resume its operation.

Of course, if conditions are too warm for the formation of snow or ice, the systems will use the opposite logic (WWSD) and tells the BAS to deactivate the system.

What types of alert functions are available to building managers?

Ideally, a snow and ice sensor interface will use error codes to signal the BAS controller if there are operational problems with the sensors.

This would allow the BAS to have feedback on the system and determine if any action needs to be taken.

Can contractors use the BACnet Sensor Interface with any snowmelt application controlled by BAS controllers?

Here, too—a versatile snow and ice sensor interface should be compatible with any snowmelt system application. After all, BAS controllers use BACnet MS/TP protocol for communication. The technology should be capable across many types of installations, such as snowmelt applications with a simple dedicated boiler, or more complex multi-boiler plants with multiple zones and mixing valves. And, the right technology should be BTL certified, providing the confidence of seamless integration.

Why is it important to control the slab temperature?

Controlling slab temperature is crucial to have an efficient snowmelt system. If the slab temperature is too low, the snow will not melt off. If the temperature is too high, the slab could be damaged and will waste a lot of energy.

Information = power

So, if you’re faced with the need to install—or retrofit—a commercial snowmelt system, and BAS is in the cards, you’re now equipped with new information and ready to reenter winter warfare. But this time, better prepared.

Cleber Alves is product manager for tekmar.

tekmar Control Systems has announced the addition of four new switching relay and zone valve control models to their existing line of zone control solutions.

tekmar now offers 2-zone pumps, 3-zone pumps, 3-zone valves, and 5-zone valves. The newly added switching relays and zone valve controls are compatible with all low-voltage thermostats and offer a variety of benefits for homeowners. These include unlimited expansion; exercising, which prevents pumps from seizing during the summer; zone priority; and priority override to protect homes from freezing over the winter months.

The switching relays and zone valve controls also send out a RoomResponse™ signal to automatically adjust boiler temperatures to improve comfort, conserve energy and save money.

Learn more about switching relays and zone valve controls by tekmar and see the complete lineup of 1-6 zone pumps and 3-6 zone valves at www.tekmarcontrols.com/products/zoning.html.

When you take pride in your work, the craftsmanship shines through, and the customer receives a reliable, comfortable radiant heating system. Tim Kuhlman, plumbing tech, Grasser’s Plumbing & Heating Inc., McNabb, Ill., is no stranger to meticulous installs and a job well done. Grasser’s is a family-owned plumbing and HVAC company serving the Illinois valley for more than 60 years.

To put it directly, the Oglesby, Ill. customer at a larger residence—3,186-sq.-ft. main floor; 3,300-sq.-ft. basement; and 1,200-sq.-ft. garage—wanted a professional install that worked. As a result, “The customer is very happy with the boiler install and performance of the system,” says Kuhlman.

As part of the solution, Kuhlman used tekmar 4-way mixing valves to raise the return temps for the garage and basement — the main floor set point is 140 degrees F; the basement and garage set points are 120 degrees F. The garage is set to 58 degrees F, the basement at 65 degrees F and the main floor to 68 degrees F.

Inside the Mechanical Room

• Boiler — Weil McLain/ultra 230 series 3
• Water heater — Navien 240A (not shown)
• Pumps — Grundfos UPS15-58FC, 3 speed circulator Relays
• Zone controls — Taco 4 Zone pump relay
• Piping – All primary and secondary piping done in copper with sweat fittings • • Main Tools Used —Bernzomatic TS8000 torch,
• Valves — Webstone isolation pump valves
• Separators —2” spirotherm air seperatore, Flexconsole expansion tank holder
• Expansion tanks —#60 Extrol expansion tank
• Other—three 12-loop 1” stainless steel uponor radiant heat manifolds and one 4-loop uponor ep manifold for garage.