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 Read more
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 Read more
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.
Summertime is the perfect time to line up your snowmelt projects and installations heading into the upcoming unpredictable weather patterns of the changing seasons. For Jason Ridgeway, owner of Ridgeway Home Services, West Chicago, Ill., a provider of indoor home comfort services for the Chicagoland area, snowmelt has been added to his comfort portfolio, and Read more
Summertime is the perfect time to line up your snowmelt projects and installations heading into the upcoming unpredictable weather patterns of the changing seasons. For Jason Ridgeway, owner of Ridgeway Home Services, West Chicago, Ill., a provider of indoor home comfort services for the Chicagoland area, snowmelt has been added to his comfort portfolio, and an additional technology he encourages potential HVAC customers to pursue. “What used to be a popular choice for larger homes, snowmelt is becoming more commonplace in ‘regular’ sized homes in the area,” said Ridgeway.
Ridgeway was called to the near west suburban neighborhood to install snowmelt for a residence’s driveway/walkway, and in addition, believe it or not, a miniature railroad/train track system—which still runs, by the way—that meanders throughout the customer’s property.
The original homeowner decided to install the train tracks in the yard for his children and grandchildren, and when he sold the home to the current owner, “the railroad had become a neighborhood institution of sorts, with neighbors pleading to keep the landmark train system, and keep it operational,” said Ridgeway.
The project began with paving contractors removing the tracks and labeling them accordingly, while a welder repaired the tracks and fitted them atop the tubing, which was installed later.
Ridgeway began the snowmelt project in September of 2017, adding the “oomph” behind the system in the basement mechanical room. Prefabbed in his shop, Ridgeway constructed the mechanical panel, which consists of Grundfos circulators, an Axiom filling station, tekmar controls for the brains behind the snowmelt system sensing, and an HTP Elite 399 boiler—installed onsite. On a side note, Ridgeway left stub outs on the boiler panel in the event of upgraded in-home radiant heat, or in the case of a future boiler change-out.
Covering approximately 3,000 sq. ft. of outdoor space—with approximately 4,500 linear ft. of REHAU PEX tubing—which includes the area of the tracks, driveway and walkways, Ridgeway began the multiple week installation—due in part to an arduous concrete pour and curing timeline—with time to spare for the upcoming winter months.
Ridgeway came away impressed with the ease of the tubing installation with both the PEXGUN installation tool, an automatic, lightweight and compact hand-held tool that attaches PEX pipe to rebar or wire mesh, and his commitment to REHAU products, in this case, the tubing uncoiler. “With the PEXGUN tubing installation tool, and REHAU uncoiler, I personally can put down 300 ft. of tubing, the same as three guys using zip ties in equal amount of time or better. The extra plus is that I don’t have to go back and cut off the tails when I’m done,” said Ridgeway.
The supply water temperature was set to 160 F with the slab melting temperature set point at 34-36 F. The cold-water shutoff was set to -10 F.
The intelligence of the system is controlled by a tekmar 090 snow and ice sensor and a tekmar 665 snowmelt control system. Basically, the in-ground sensor—used in conjunction with the tekmar snow melting controls—“senses” the precipitation and intuitively correlates the freezing or below freezing temperatures and automatically detects precipitation as snow or sleet on the applicable surface, which tells the system to activate.
The tekmar 665 control uses the snow/ice detection sensor in order to automatically melt snow using Pulse Width Modulation and slab outdoor reset to maintain slab temperature. It is capable of controlling a single boiler, a system pump, and providing a signal when melting is enabled.
The existing system is one zone but is set up for the possibility of adding multiple zones, which is advantageous to Ridgeway. He will be going back to the residence to add snowmelt to existing pavers around the pool area in the back of the house. This added snowmelt will pull hot water from the existing HTP boiler.
Ridgeway ran into one challenge during the installation when the system, upon initial start-up, kept experiencing a drop in pressure. Initially thinking there was a leak in the lines somewhere, Ridgeway eventually resolved the issue by diagnosing the problem, finding an unusually high content of air in the system. An elongated purging of excess air in the system solved that minor glitch.
The end result is a beautifully paved snowmelt area, complete with added railroad tracks crisscrossing through the driveway. Needless to say, when all was said and done, and a full season of experiencing snowstorms, ice and a wintry mix in between, the end result was one happy homeowner.
Manifold images: All REHAU manifolds are pressurized to 80psi.
Complex hydronic systems are so 2008, at least according to Mechanical-Hub ProStaffer Andy Mickelson, who owns Mickelson Plumbing and Heating in Missoula, Mont. His three-man shop does plenty of high-end residential work, and even here—no—especially here, their recipe for success, serviceability and efficiency includes a heavy dose of “keep it simple.” On a custom home Read more
Complex hydronic systems are so 2008, at least according to Mechanical-Hub ProStaffer Andy Mickelson, who owns Mickelson Plumbing and Heating in Missoula, Mont. His three-man shop does plenty of high-end residential work, and even here—no—especially here, their recipe for success, serviceability and efficiency includes a heavy dose of “keep it simple.”
On a custom home, where some contractors may be tempted to stack the material list high and deep, Andy does the opposite. He takes a step back from the blueprints and figures out how to use the fewest components needed without any compromise. Numerous zones, DHW production, multiple supply temperatures and snowmelt loops can and are all handled without making things more complicated.
“There are a number of things you can do to keep systems simple,” said Mickelson. “I make sure to avoid ‘inadvertent’ redundancy: that is, two products that accomplish the same task.
Proper sizing of radiation, pipe, pumps and boilers accurately is obviously important, too. Picking a control system that accomplishes what you need and nothing more is helpful.
Another thing we began doing a few years ago—and have noticed an improvement since – is sizing and grouping our zones to the capacity of a specific pump, instead for creating a zone with no real parameters, and trying to find a pump that fits the zone or zone group.”
Like a round peg in a round hole, selecting your circulator first can save a lot of trouble, as well as the issues that come with over- or under-pumping a system.
Starting in late October of last year, Mickelson was hired for a job that would test his ability to “keep it simple.”
Just out of town, the customer had purchased a nice lot with an older, 800-sq.-ft. home. The house was leveled and the basement foundation was re-used. The plan was to build a new 5,000-sq.-ft., two-story home on top of and around the original foundation.
Pick the pump first
“Like we do on all our jobs, I interviewed the homeowner long before we started the work, in order to really understand what they wanted,” said Mickelson. “Comfort was paramount, and budget not as much. So a thin concrete slab covers all radiant tubing, which is set at nine-inch centers.”
Before Mickelson started his loop layouts, he chose the Taco VT2218 variable speed circulator to serve all of the zones, with a total of six pumps. Additionally, Taco 007e single-speed ECM circulators are used on the 200 MBH fire-tube boiler and the indirect water heater.
“I like a Delta-T pump on a job like this, but another reason I used the VT2218 is for its broad pump curve, and we made use of it,” explained Mickelson. “It’s also very easy to program. Each radiant pump serves a group of zones. The zones are paired up according to the pump’s capacity, in terms of both head loss and flow rate. That way there aren’t any extra, underutilized circulators.”
Once the pump has been selected and the heat loss has been completed, the zones can be designed to fit the home. A common misconception about radiant circuits is that they must be as close to 300 feet long as possible, this just isn’t true. By dropping the length of each circuit, the head loss can be comfortably managed. The downfall to this is that the zone may require more circuits, but honestly the difference between five circuits and seven is minimal. It’s the same amount of tubing, no real noticeable increase in labor, just a larger manifold and a manageable head loss.
Through zone valves, each pump supplies the appropriate amount of water and heat to a Watts Radiant stainless steel manifold, located remotely. Half-inch Watts RadiantPERT tubing was laid out before the gypcrete was poured.
“We chose the PERT instead of PEX because the radiant work was done throughout the winter. With spells of sub-zero weather, the increased flexibility of PERT was a huge benefit, especially considering our tight tube spacing.”
Because of the hydronic radiators, unit ventilator and snowmelt, the boiler maintains the buffer tank at 140°F at an outdoor design condition of -15°F. To make low temp water for the radiant zones, a Watts 4-way mixing valve with a tekmar 741 actuating motor was used. The 741 communicates with a tekmar 402 House Control in order to supply the exact radiant temperature need based on the outdoor temperature.
“The mixing valve sets the final delivery temp to all the low-temp zones,” said Mickleson. “It’s one of three elements at play here that really allow us to provide the exact temperature and flow rate to the radiant zones, so we’re really capitalizing on the primary/secondary piping, and squeezing every last ounce of comfort and efficiency out of the system. The other two elements are the outdoor reset on the higher temp boiler zones, and the variable-speed, Delta-T pumps. They all work hand in hand.”
The home has several areas with structural elements which made installing some of the tubing a challenging. Because of this, Mickelson had no choice but to run PEX supply and return piping through exterior walls. As a guard against the challenge of Montana winters, he wanted to run a glycol solution in the system. He installed a Neutra-Safe system feeder, which is an all-in-one reservoir, pump and control.
The fourth and fifth VT2218 circulators serve the home’s three high-temp zones directly out of the buffer tank. In the basement, where the existing, uninsulated slab is still in place, Runtal baseboard was used in lieu of radiant tubing. Mickelson had considered ceiling radiant, but there wasn’t enough height to allow it. The circulator used for the baseboard zone also supplies water to the 12,000 BTU Smith Environmental unit ventilator in the garage attic.
The last variable-speed circulator serves as the snow melt system pump on the loop side of the brazed-plate heat exchanger. Mickelson uses a tekmar 654 Snowmelt Control to manage automatic operation and maintain a 25°F Delta-T across the 400 square-foot zone. This control features a snow and ice sensor that’s set in concrete when poured. The snowmelt loops also utilize a second Neutra-Safe System Feeder.
“Because of the components used and a thoughtful design, we’re covering five different loads with one boiler while installing it in a relatively tight space, all without being overly complicated,” said Mickelson.
“In the case of an emergency, I only have to deal with a single control system or one replacement pump,” he added. And with all that said, I can’t think of a quieter, more comfortable, or higher efficiency heating system.”
Mickelson is now going over a punch list, and looking forward to the feedback from the customer. He’s expecting rave reviews about the comfort level, and complete satisfaction when the owner receives their first propane bill.
Fellow Hydronic Professionals,, I have been the director of the RPA now for 2 and 1/3 years. It has been an arduous journey, with some ups and some downs, mostly ups, but we (I especially) do this for the industry. We now have in place one of the most dynamic group of people (members on Read more
I have been the director of the RPA now for 2 and 1/3 years. It has been an arduous journey, with some ups and some downs, mostly ups, but we (I especially) do this for the industry.
We now have in place one of the most dynamic group of people (members on committees and members in general) and are kicking butt and taking names. We have an actual Hydronics/Radiant Code that is part of the Uniform family of codes (Uniforms Solar Energy Hydronics Code) and are in the final stages of developing an ANSI recognized, ASSE developed Professional Certification program for designers and installers.
We have and continue to add instructors to, our online university, RPAU, with HeatSpring offering some of the best instructors time and money can buy, making education of yourself and your employees available at YOUR convenience.
We recently inked a deal with Tom Grandy and Associates to help show experienced contractors how to turn their hard work into a good profit margins so they can retire comfortably or live well before retirement.
We have inked a deal with Kilowatt Financial to provide low interest, high dollar (up to $30K) financing IN THE CONSUMERS HOUSE. (less than 30 minute approvals online)
We have renewed commitments from UPS offering our members a significant discount on shipping less than truck loads.
We have a monthly newsletter available to members only.
We have printed magazines to help you sell radiant comfort (walls floors and ceilings) to the consumers.
We have monthly Lunch and Learn webinars to keep you abreast of the latest and greatest in our industry.
We have HydroniX Talk (which is on summer vacation) which is also available to members only, and will now be taking place early evenings during the week, beginning this coming fall, featuring the likes of Dan Holohan and many other notable hydronics pioneers.
All of this for a contractor for less than $1.00 per day (actually less than that because the $300/year fee is good for 3 employees) as well as access to some of the best minds this industry has to offer (locked access LinkedIn accounts).
And we continue to look for ways to promote this wonderful industry of ours so that we can prove to the world something that most people here have known for a long time, that being that hydronics is THE most efficient method of transferring energy from point A to point B, or from point B to point A.
We have legislative power in Washington DC looking out for our industry’s interests. (The old RPA was not allowed to lobby)
There’s only one major missing component…..
>>> YOU! <<<
I and my membership committee (and the other 7 committees) are baffeled as to why former members of the old RPA and new potential members are not coming back into the fold.
So, I’d like to ask some questions and clear up some rumors.
Rumor 1: IAPMO runs the RPA. Wrong, WE run the RPA. IAPMO owns it lock stock and barrel, and provides us with all of the tools and support we need to further its goals, but the RPA is run by its members. It is an organization OF the members, BY the members, FOR the members.
Rumor 2: RPA is dead. Wrong, it came extremely close to going under during the economic down turn, and if IAPMO had not intervened, it would have gone down in flames. Fortunately, IAPMO caught it before it plowed into the ground, gave it a soft landing, re-painted the plane, refueled it and sent it back up into the air.
Rumor 3: IAPMO is dead. This couldn’t be further from the truth. IAPMO is the largest CDO (Code Development Organization) in the world. In fact they are expanding and now have offices around the world, helping to establish plumbing and mechanical codes around the world.
Rumor 4: IAPMO and the RPA are too big for me to consider joining. WRONG, these organizations are here to support you, not fight you. Every code and standard that is developed by these organizations are done so under a very tightly watched and controlled ANSI Open Consensus process. No complaint goes unattended or ignored. All concerns are addressed until there are no more concerns.
So, my question to you is why have you (contractors, designers, installers, equipment manufacturers, manufacturer rep agencies and others) not joined, or rejoined this fantastic organization? There is strength in numbers, and if we as an industry don’t band together real soon, there is a real possibility that our industry will be put out of business by some very savvy foreign interests who have stated publicly that their intent is to take over ALL methods of heating and cooling.
Tell me what rumors you’ve heard, or why it is that you haven’t joined this organization. We are all ears, and we want to make certain that this machine is your machine, and that it does work for YOU, the industry.
I’d also like to thank all of our volunteers and our board of directors for their guidance in getting the ship to this point. Without your help, we wouldn’t have gotten this far. THANK YOU.
Now, tell me what your concerns are?
If you’d like to join, go to www.radiantprofessionalsalliance.org and click on the JOIN button, or simply call Alan Wald, our Vice President of Memberships at 909-472-4211and he or one of his staff can get you signed up over the phone. Easy squeasy lemon peasy.
Thank you for your consideration, and thanks to the Mechanical Hub for being a member and allowing us to use this venue.
Executive Director, Radiant Professionals Alliance