tekmar

According to Forbes, the occupancy rate among US multi-family housing units rose to 96.9 percent in mid-2021, and the trend has continued post-pandemic.

With real-estate prices increasing sharply and rent costs reaching all-time highs, there’s more incentive than ever to renovate, update and repurpose commercial and light commercial facilities, whether properties include multi-tenant housing, mixed office space, retail locations, etc.

Compared to new construction, however, this leaves property owners, managers and mechanical contractors at a disadvantage: older but serviceable mechanical equipment can be difficult to integrate with a smart and connected control platform.

This may be especially true in northern climates, where hydronic systems have been the default source of space heat due to boiler efficiency, comfort, longevity and the ability to provide ample domestic hot water.

Older boiler plants generally lack connectivity in the 50,000-square-foot and under market, where installing a building automation system (BAS) may not be worth the expense.

James Dice, PE, CEM, CMVP, founder of Nexus Labs, recently wrote a white paper titled “The Untapped 87%: Simplifying Controls Technology for Small Buildings.”  In it, the author explains that a 20,500 square foot building was retrofitted with a BAS by the United States Department of Energy’s Pacific Northwest Laboratory (PNNL) in 2010.  Within the first two years, this lead to a 22% energy savings, 25% return on investment and a “dramatic decline” in occupant comfort complaints.

The white paper goes on to explain that buildings smaller than 50,000 square feet represent 94% of commercial buildings in the US, 44% of electricity use, and 44% of total energy use.  Yet, only 13% of these buildings are equipped with a BAS.

The reason? BAS systems are either too complex or not cost effective enough for the average building owner.  BAS frequently cost $50k to $100k, which exceeds the fiscal budgets of many building owners. In addition, they require an expensive annual service plan.

Because of this, there is massive opportunity to reduce energy consumption and simplify maintenance with the use of new, connected HVAC system controls without installing a BAS.

Aging boiler plants

Many commercial boiler plants feature multiple boilers for staged input or redundancy.  Over the years, as various boilers were replaced, it’s not uncommon to have multiple different boiler models serving the same system.

For example, a system that was originally served by three conventional boilers of the same model might have been retrofitted with a single condensing boiler to replace two of the originals, while the third existing boiler remained in place for supplemental heat on design days.

In new construction applications or in systems where every boiler in the system is replaced, the boiler manufacturer’s onboard cascading controls are often used for lead-lag cycling of the units, though establishing remote access can still be a frustration.

Fleet management is a major problem for facility managers. The heating system equipment is usually different in every building. This is due to the buildings being built and updated at different times, and buildings being acquired and sold by the management company.

So facility managers, property owners and mechanical contractors involved with light commercial systems too small to warrant the installation of a BAS are left asking how to control and remotely monitor their systems.  If multiple properties are involved, the challenge is multiplied.

Evolving needs

“We’ve been building multi-stage boiler controls for over 30 years,” said Jay Vath, life cycle engineer at tekmar Control Systems.  “There are a number of other control manufacturers with similar products, and for everyone in this market sector, the initial goal was to provide outdoor temperature reset for boilers that didn’t offer it.”

The demand for features in a boiler control package evolved along with the boilers themselves, along with the need for greater efficiency and control.  Boiler manufacturers began offering outdoor reset and onboard staging across multiple, identical units.  So the focus shifted to remote access, existing boiler plants, and the installation of hybrid condensing and non-condensing boilers plants.

Control manufacturers introduced modules that offered some degree of remote monitoring capability for boiler plants, but one large issue remained: Many existing boiler plants included disparate models, often with decades separating them.  There was no way to aggregate different brands and models onto a single, web-enabled control platform short of installing a BAS.

Long-sought solution

The primary drawbacks to installing a BAS solely for boiler plant control in a facility that otherwise doesn’t need it are the initial and maintenance cost, but equally important is the level of responsiveness on the part of the controls contractor.  A BAS system creates an additional hurdle between the system and the service contractor.  If an alert is generated by the boiler plant, the controls contractor – who may or may not be responsive in a reasonable amount of time – notifies the service contractor.

Eliminating the controls contractor and creating a direct conduit from the boiler plant to the service contractor reduces expense and expedites the service response.

“This is a key consideration for any connected boiler control,” said Vath.  “It puts power in the hands of the service contractor, while providing remote monitoring capability for systems that may feature a number of different boiler makes models.”

Tekmar’s Smart Boiler Control 294 is an internet connected control that can be accessed via any web-enabled device for remote boiler plant monitoring and control.  A boiler wizard provides integration with thousands of boiler models, and various levels of control and permission can be set for specific individuals, such as the service contractor, a facility manager and the building owner.

Compound savings

“Installing a smart and connected boiler plant control system provides real potential to save money on energy and maintenance,” said Vath.  “Compared to a fixed operating setpoint system, outdoor reset alone can save upwards of 30 percent in fuel expenses.”

But there are many other savings advantages, some not as easy to quantify.  Automatic boiler and pump shutoff reduces energy use when the system isn’t needed.  Short-cycling is reduced or eliminated.  Rotating boilers balances runtime hours, providing maintenance and longevity advantages.  Staging boilers correctly helps accurately match the heating input to the load.  Conventional and condensing boilers in the same plant can be grouped together and staged independently, keeping the least efficient appliance offline until needed.  Some savings though, take place outside the mechanical room.

“With the notifications and insight that web-enabled boiler controls provide, the service technician knows what’s needed in the event of an alert, which they receive via email, text or push notification,” said Vath.  “For example, a pressure input could indicate that the expansion tank’s diaphragm is flooded, so the technician would know in advance to put a replacement in the truck.  With remote monitoring, dispatching occurs quickly.  Alternatively, if the control generates an alert on an issue that can wait until the next scheduled service interval, an unnecessary trip is eliminated.  This kind of information reduces unnecessary expense and allows service professionals to be proactive.  The Watts OnSite app provides notifications when boilers and pumps are due for servicing based on run time hours. This allows for the creation of scheduled maintenance plans.”

Using a flexible boiler plant control also offers cost saving options in the event of a retrofit.  If the ability to connect an old boiler to a new control system is the only factor prohibiting a facility from leaving existing capacity online while retrofitting a portion of the mechanical system, that’s no longer a concern.  New boilers can be paired with old boilers for backup heat, ultimately reducing the amount of new firing capacity needed.

Forward-backward compatibility

“For systems that already include tekmar boiler controls, updating the system with the 294 is simple,” said Vath.  “All the equipment applications we’ve had in the past are covered by the 294.”

Similarly, the 294 can be quickly updated as new apps or other improvements are introduced.  Updates and new features are sent to existing units as they’re developed.  This is a big advantage for code compliance.

“In the future, if certain codes are accepted that require specific monitoring parameters, the 294 is designed to be updated to provide reporting as required.”

This flexibility allows the owner to remain current, not just to become current now.   It’s a matter of being proactive, not reactive.

For example, 30 U.S. municipalities across the US are currently phasing in higher standards for commercial real estate emission reductions and energy consumption.  A long-known problem is that systems become less efficient over time due to poor maintenance.  Remote monitoring is a key method to keep the boiler system operating at the designed efficiency.

Customized control

Web-enabled boiler controls offer a “BAS Lite” solution.    With that comes substantial customization.

“The fact that dissimilar boiler technology is being controlled by a single system, tailored to the needs of an individual customer and property means that the control platform has to be extremely versatile,” said Vath.  “For that reason, the 294 can be configured for many combinations.”

For example, a fixed “lead” boiler can be established, in the event that a draft is needed for one of the boilers in the system.  A fixed “last” can also be established in the event that a conventional boiler is used only under design conditions, allowing condensing units to fire first.

Control can be established for firing rates or water temperatures, and the system can switch between the two depending on the call for heat.  A DHW call may create a water temperature setpoint while a call for space heat may dictate boiler firing rate, and so on.

Security and ownership

Much of the remote access in buildings from the past 20 or 30 years was closed-loop, like key card room access, fire alarms, auto-dialers, etc.  To provide full-featured remote access to a variety of team members, an internet connection is needed for a cloud-based platform.

“Fundamentally, where we’ve changed gears from what was done in the past is connectivity,” said Vath.  “Once the 294 is connected via Wi-Fi or Ethernet, we use the Watts Onsite app or browser interface to remotely access the device with the ability to adjust every setting in the control.  This has a great deal of value for property management groups that have a fleet of buildings, seeking control consistency across properties and boiler plants.”

Security is built into the control and into the Microsoft Azure platform that it operates on.  Access is end-to-end encrypted, just like a banking app.  Login information is specific to each individual on the team and does not need to be shared among members.  The physical control also includes a passcode to prevent unauthorized access.

The program and information resident on the physical controller is a digital twin of the control on the remote device.  The virtual device can be modified in real-time, immediately updating the physical device.  This reduces trips to the property and allows every member of the team to access the system.  Team members who have access to the digital twin can be added and removed, and different levels of access can be established for each.

The new control offers as many advantages to the owner as it does to the service professional. Ownership can be transferred in the event of property sale.  Transfer of responsibility is quick and simple, if the service contract changes hands.

The property owner can also monitor and review the responsiveness of the contractor.  An acknowledgement is logged when the service professional reviews the alarm.  This allows the owner to see if they’re receiving the service they’re paying for.

Ultimate flexibility

Creating remote access for existing light commercial boiler plants requires a great deal of flexibility.  Varying loads, miss-matched boiler models and different building codes to conform to all require a control package to be extremely flexible.  Looking ahead, the potential addition of air-to-water heat pumps is something that a modern boiler plant control system has to be able to facilitate.

“The only constant is change,” said Vath.  “Building owners change, technology changes, service contracts change, codes change.  A modern boiler control package must adapt to these transitions.”

This piece was contributed by Eric Balt, technical sales manager for tekmar Control Systems and Mercedeh Fallahkhair, senior product manager for tekmar Control Systems

References:

Dice, J. “The Untapped 87%: Simplifying Controls Technology for Small Buildings”, Accessed June 2023

Cole, R. (2021, November 8). These are the Multifamily Trends Experts Are Predicting for 2022. Forbes.https://www.forbes.com/sites/reginacole/2021/11/08/multifamily-trends-in-2022/?sh=523a0e4b82bb Accessed June 2023

Sadovi, M. W. (2022, November 29). Five US cities target building energy use, emissions with fines. CFO Dive. https://www.cfodive.com/news/five-us-cities-target-building-energy-use-emissions-fines/637538/, Accessed June 2023

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.

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.

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.

“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.”

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.